diff --git a/assignment-client/CMakeLists.txt b/assignment-client/CMakeLists.txt
index abb94f95e3c..345118a89b0 100644
--- a/assignment-client/CMakeLists.txt
+++ b/assignment-client/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME assignment-client)
 
-setup_hifi_project(Core Gui Network Script Quick WebSockets)
+setup_hifi_project(Core Gui Network Quick WebSockets)
 
 # Fix up the rpath so macdeployqt works
 if (APPLE)
diff --git a/assignment-client/src/Agent.cpp b/assignment-client/src/Agent.cpp
index 4b9b2d5095f..121276efcc1 100644
--- a/assignment-client/src/Agent.cpp
+++ b/assignment-client/src/Agent.cpp
@@ -27,6 +27,7 @@
 #include <DebugDraw.h>
 #include <EntityScriptingInterface.h>
 #include <LocationScriptingInterface.h>
+#include <AudioScriptingInterface.h>
 #include <MessagesClient.h>
 #include <NetworkAccessManager.h>
 #include <NodeList.h>
@@ -34,7 +35,9 @@
 #include <ResourceCache.h>
 #include <ResourceScriptingInterface.h>
 #include <ScriptCache.h>
+#include <ScriptEngine.h>
 #include <ScriptEngines.h>
+#include <ScriptManager.h>
 #include <SoundCacheScriptingInterface.h>
 #include <SoundCache.h>
 #include <UserActivityLoggerScriptingInterface.h>
@@ -56,7 +59,7 @@
 
 #include "entities/AssignmentParentFinder.h"
 #include "AssignmentDynamicFactory.h"
-#include "RecordingScriptingInterface.h"
+#include <recording/RecordingScriptingInterface.h>
 #include "AbstractAudioInterface.h"
 #include "AgentScriptingInterface.h"
 
@@ -180,7 +183,7 @@ static const QString AGENT_LOGGING_NAME = "agent";
 
 void Agent::run() {
     // Create ScriptEngines on threaded-assignment thread then move to main thread.
-    DependencyManager::set<ScriptEngines>(ScriptEngine::AGENT_SCRIPT)->moveToThread(qApp->thread());
+    DependencyManager::set<ScriptEngines>(ScriptManager::AGENT_SCRIPT)->moveToThread(qApp->thread());
 
     DependencyManager::set<ScriptCache>();
 
@@ -372,7 +375,7 @@ void Agent::executeScript() {
     // the following block is scoped so that any shared pointers we take here
     // are cleared before we call setFinished at the end of the function
     {
-        _scriptEngine = scriptEngineFactory(ScriptEngine::AGENT_SCRIPT, _scriptContents, _payload);
+        _scriptManager = scriptManagerFactory(ScriptManager::AGENT_SCRIPT, _scriptContents, _payload);
 
         // setup an Avatar for the script to use
         auto scriptedAvatar = DependencyManager::get<ScriptableAvatar>();
@@ -386,10 +389,11 @@ void Agent::executeScript() {
         scriptedAvatar->getHeadOrientation();
 
         // give this AvatarData object to the script engine
-        _scriptEngine->registerGlobalObject("Avatar", scriptedAvatar.data());
+        auto scriptEngine = _scriptManager->engine();
+        scriptEngine->registerGlobalObject("Avatar", scriptedAvatar.data());
 
         // give scripts access to the Users object
-        _scriptEngine->registerGlobalObject("Users", DependencyManager::get<UsersScriptingInterface>().data());
+        scriptEngine->registerGlobalObject("Users", DependencyManager::get<UsersScriptingInterface>().data());
 
         auto player = DependencyManager::get<recording::Deck>();
         connect(player.data(), &recording::Deck::playbackStateChanged, [&player, &scriptedAvatar] {
@@ -493,26 +497,26 @@ void Agent::executeScript() {
         });
 
         auto avatarHashMap = DependencyManager::set<AvatarHashMap>();
-        _scriptEngine->registerGlobalObject("AvatarList", avatarHashMap.data());
+        scriptEngine->registerGlobalObject("AvatarList", avatarHashMap.data());
 
         // register ourselves to the script engine
-        _scriptEngine->registerGlobalObject("Agent", new AgentScriptingInterface(this));
+        scriptEngine->registerGlobalObject("Agent", new AgentScriptingInterface(this));
 
-        _scriptEngine->registerGlobalObject("AnimationCache", DependencyManager::get<AnimationCacheScriptingInterface>().data());
-        _scriptEngine->registerGlobalObject("SoundCache", DependencyManager::get<SoundCacheScriptingInterface>().data());
+        scriptEngine->registerGlobalObject("AnimationCache", DependencyManager::get<AnimationCacheScriptingInterface>().data());
+        scriptEngine->registerGlobalObject("SoundCache", DependencyManager::get<SoundCacheScriptingInterface>().data());
 
-        QScriptValue webSocketServerConstructorValue = _scriptEngine->newFunction(WebSocketServerClass::constructor);
-        _scriptEngine->globalObject().setProperty("WebSocketServer", webSocketServerConstructorValue);
+        ScriptValue webSocketServerConstructorValue = scriptEngine->newFunction(WebSocketServerClass::constructor);
+        scriptEngine->globalObject().setProperty("WebSocketServer", webSocketServerConstructorValue);
 
         auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
 
-        _scriptEngine->registerGlobalObject("EntityViewer", &_entityViewer);
+        scriptEngine->registerGlobalObject("EntityViewer", &_entityViewer);
 
-        _scriptEngine->registerGetterSetter("location", LocationScriptingInterface::locationGetter,
+        scriptEngine->registerGetterSetter("location", LocationScriptingInterface::locationGetter,
                                             LocationScriptingInterface::locationSetter);
 
         auto recordingInterface = DependencyManager::get<RecordingScriptingInterface>();
-        _scriptEngine->registerGlobalObject("Recording", recordingInterface.data());
+        scriptEngine->registerGlobalObject("Recording", recordingInterface.data());
 
         entityScriptingInterface->init();
 
@@ -522,8 +526,8 @@ void Agent::executeScript() {
 
         DependencyManager::set<AssignmentParentFinder>(_entityViewer.getTree());
 
-        DependencyManager::get<ScriptEngines>()->runScriptInitializers(_scriptEngine);
-        _scriptEngine->run();
+        DependencyManager::get<ScriptEngines>()->runScriptInitializers(_scriptManager);
+        _scriptManager->run();
 
         Frame::clearFrameHandler(AUDIO_FRAME_TYPE);
         Frame::clearFrameHandler(AVATAR_FRAME_TYPE);
@@ -602,7 +606,7 @@ void Agent::setIsAvatar(bool isAvatar) {
             // start the timer
             _avatarQueryTimer->start(AVATAR_VIEW_PACKET_SEND_INTERVAL_MSECS);
 
-            connect(_scriptEngine.data(), &ScriptEngine::update,
+            connect(_scriptManager.get(), &ScriptManager::update,
                     scriptableAvatar.data(), &ScriptableAvatar::update, Qt::QueuedConnection);
 
             // tell the avatarAudioTimer to start ticking
@@ -638,7 +642,7 @@ void Agent::setIsAvatar(bool isAvatar) {
                 nodeList->sendPacket(std::move(packet), *node);
             });
 
-            disconnect(_scriptEngine.data(), &ScriptEngine::update,
+            disconnect(_scriptManager.get(), &ScriptManager::update,
                        scriptableAvatar.data(), &ScriptableAvatar::update);
 
             QMetaObject::invokeMethod(&_avatarAudioTimer, "stop");
@@ -875,7 +879,7 @@ void Agent::aboutToFinish() {
 
     // drop our shared pointer to the script engine, then ask ScriptEngines to shutdown scripting
     // this ensures that the ScriptEngine goes down before ScriptEngines
-    _scriptEngine.clear();
+    _scriptManager.reset();
 
     {
         DependencyManager::get<ScriptEngines>()->shutdownScripting();
@@ -895,8 +899,8 @@ void Agent::aboutToFinish() {
 }
 
 void Agent::stop() {
-    if (_scriptEngine) {
-        _scriptEngine->stop();
+    if (_scriptManager) {
+        _scriptManager->stop();
     } else {
         setFinished(true);
     }
diff --git a/assignment-client/src/Agent.h b/assignment-client/src/Agent.h
index eb58e32897c..efed440a8ae 100644
--- a/assignment-client/src/Agent.h
+++ b/assignment-client/src/Agent.h
@@ -15,12 +15,12 @@
 #include <memory>
 #include <vector>
 
-#include <QtScript/QScriptEngine>
 #include <QtCore/QObject>
 #include <QtCore/QSharedPointer>
 #include <QtCore/QUrl>
 #include <QtCore/QTimer>
 #include <QUuid>
+#include <QtCore/QSharedPointer>
 
 #include <EntityEditPacketSender.h>
 #include <EntityTree.h>
@@ -29,11 +29,17 @@
 
 #include <plugins/CodecPlugin.h>
 
+#include <Sound.h>
 #include "AudioGate.h"
 #include "MixedAudioStream.h"
 #include "entities/EntityTreeHeadlessViewer.h"
 #include "avatars/ScriptableAvatar.h"
 
+class ScriptEngine;
+class ScriptManager;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
+
 class Agent : public ThreadedAssignment {
     Q_OBJECT
 
@@ -90,7 +96,7 @@ private slots:
     void encodeFrameOfZeros(QByteArray& encodedZeros);
     void computeLoudness(const QByteArray* decodedBuffer, QSharedPointer<ScriptableAvatar>);
 
-    ScriptEnginePointer _scriptEngine;
+    ScriptManagerPointer _scriptManager;
     EntityEditPacketSender _entityEditSender;
     EntityTreeHeadlessViewer _entityViewer;
 
diff --git a/assignment-client/src/avatars/ScriptableAvatar.cpp b/assignment-client/src/avatars/ScriptableAvatar.cpp
index 752eaf81d28..15c9fce788d 100644
--- a/assignment-client/src/avatars/ScriptableAvatar.cpp
+++ b/assignment-client/src/avatars/ScriptableAvatar.cpp
@@ -17,16 +17,18 @@
 
 #include <shared/QtHelpers.h>
 #include <AnimUtil.h>
+#include <AvatarHashMap.h>
 #include <ClientTraitsHandler.h>
 #include <GLMHelpers.h>
 #include <ResourceRequestObserver.h>
 #include <AvatarLogging.h>
 #include <EntityItem.h>
 #include <EntityItemProperties.h>
+#include <NetworkAccessManager.h>
 #include <NetworkingConstants.h>
 
 
-ScriptableAvatar::ScriptableAvatar() {
+ScriptableAvatar::ScriptableAvatar(): _scriptEngine(newScriptEngine()) {
     _clientTraitsHandler.reset(new ClientTraitsHandler(this));
 }
 
@@ -311,7 +313,7 @@ AvatarEntityMap ScriptableAvatar::getAvatarEntityDataInternal(bool allProperties
             EntityItemProperties properties = entity->getProperties(desiredProperties);
 
             QByteArray blob;
-            EntityItemProperties::propertiesToBlob(_scriptEngine, sessionID, properties, blob, allProperties);
+            EntityItemProperties::propertiesToBlob(*_scriptEngine, sessionID, properties, blob, allProperties);
             data[id] = blob;
         }
     });
@@ -335,7 +337,7 @@ void ScriptableAvatar::setAvatarEntityData(const AvatarEntityMap& avatarEntityDa
     while (dataItr != avatarEntityData.end()) {
         EntityItemProperties properties;
         const QByteArray& blob = dataItr.value();
-        if (!blob.isNull() && EntityItemProperties::blobToProperties(_scriptEngine, blob, properties)) {
+        if (!blob.isNull() && EntityItemProperties::blobToProperties(*_scriptEngine, blob, properties)) {
             newProperties[dataItr.key()] = properties;
         }
         ++dataItr;
@@ -415,7 +417,7 @@ void ScriptableAvatar::updateAvatarEntity(const QUuid& entityID, const QByteArra
 
     EntityItemPointer entity;
     EntityItemProperties properties;
-    if (!EntityItemProperties::blobToProperties(_scriptEngine, entityData, properties)) {
+    if (!EntityItemProperties::blobToProperties(*_scriptEngine, entityData, properties)) {
         // entityData is corrupt
         return;
     }
diff --git a/assignment-client/src/avatars/ScriptableAvatar.h b/assignment-client/src/avatars/ScriptableAvatar.h
index 8e58108e8cb..f6c721a3246 100644
--- a/assignment-client/src/avatars/ScriptableAvatar.h
+++ b/assignment-client/src/avatars/ScriptableAvatar.h
@@ -220,7 +220,7 @@ public slots:
     QHash<QString, int> _fstJointIndices; ///< 1-based, since zero is returned for missing keys
     QStringList _fstJointNames; ///< in order of depth-first traversal
     QUrl _skeletonFBXURL;
-    mutable QScriptEngine _scriptEngine;
+    mutable ScriptEnginePointer _scriptEngine;
     std::map<QUuid, EntityItemPointer> _entities;
 
     /// Loads the joint indices, names from the FST file (if any)
diff --git a/assignment-client/src/scripts/EntityScriptServer.cpp b/assignment-client/src/scripts/EntityScriptServer.cpp
index 4ff920516af..3b8144164f9 100644
--- a/assignment-client/src/scripts/EntityScriptServer.cpp
+++ b/assignment-client/src/scripts/EntityScriptServer.cpp
@@ -14,7 +14,9 @@
 #include <mutex>
 
 #include <AudioConstants.h>
+#include <AudioScriptingInterface.h>
 #include <AudioInjectorManager.h>
+#include <AvatarHashMap.h>
 #include <ClientServerUtils.h>
 #include <DebugDraw.h>
 #include <EntityNodeData.h>
@@ -130,7 +132,7 @@ void EntityScriptServer::handleEntityScriptGetStatusPacket(QSharedPointer<Receiv
         replyPacketList->writePrimitive(messageID);
 
         EntityScriptDetails details;
-        if (_entitiesScriptEngine->getEntityScriptDetails(entityID, details)) {
+        if (_entitiesScriptManager->getEntityScriptDetails(entityID, details)) {
             replyPacketList->writePrimitive(true);
             replyPacketList->writePrimitive(details.status);
             replyPacketList->writeString(details.errorInfo);
@@ -175,7 +177,7 @@ void EntityScriptServer::handleSettings() {
 }
 
 void EntityScriptServer::updateEntityPPS() {
-    int numRunningScripts = _entitiesScriptEngine->getNumRunningEntityScripts();
+    int numRunningScripts = _entitiesScriptManager->getNumRunningEntityScripts();
     int pps;
     if (std::numeric_limits<int>::max() / _entityPPSPerScript < numRunningScripts) {
         qWarning() << QString("Integer multiplication would overflow, clamping to maxint: %1 * %2").arg(numRunningScripts).arg(_entityPPSPerScript);
@@ -236,7 +238,7 @@ void EntityScriptServer::pushLogs() {
 
 void EntityScriptServer::handleEntityScriptCallMethodPacket(QSharedPointer<ReceivedMessage> receivedMessage, SharedNodePointer senderNode) {
 
-    if (_entitiesScriptEngine && _entityViewer.getTree() && !_shuttingDown) {
+    if (_entitiesScriptManager && _entityViewer.getTree() && !_shuttingDown) {
         auto entityID = QUuid::fromRfc4122(receivedMessage->read(NUM_BYTES_RFC4122_UUID));
 
         auto method = receivedMessage->readString();
@@ -250,13 +252,13 @@ void EntityScriptServer::handleEntityScriptCallMethodPacket(QSharedPointer<Recei
             params << paramString;
         }
 
-        _entitiesScriptEngine->callEntityScriptMethod(entityID, method, params, senderNode->getUUID());
+        _entitiesScriptManager->callEntityScriptMethod(entityID, method, params, senderNode->getUUID());
     }
 }
 
 
 void EntityScriptServer::run() {
-    DependencyManager::set<ScriptEngines>(ScriptEngine::ENTITY_SERVER_SCRIPT);
+    DependencyManager::set<ScriptEngines>(ScriptManager::ENTITY_SERVER_SCRIPT);
     DependencyManager::set<EntityScriptServerServices>();
     DependencyManager::set<AvatarHashMap>();
 
@@ -446,7 +448,8 @@ void EntityScriptServer::selectAudioFormat(const QString& selectedCodecName) {
 
 void EntityScriptServer::resetEntitiesScriptEngine() {
     auto engineName = QString("about:Entities %1").arg(++_entitiesScriptEngineCount);
-    auto newEngine = scriptEngineFactory(ScriptEngine::ENTITY_SERVER_SCRIPT, NO_SCRIPT, engineName);
+    auto newManager = scriptManagerFactory(ScriptManager::ENTITY_SERVER_SCRIPT, NO_SCRIPT, engineName);
+    auto newEngine = newManager->engine();
 
     auto webSocketServerConstructorValue = newEngine->newFunction(WebSocketServerClass::constructor);
     newEngine->globalObject().setProperty("WebSocketServer", webSocketServerConstructorValue);
@@ -456,42 +459,42 @@ void EntityScriptServer::resetEntitiesScriptEngine() {
 
     // connect this script engines printedMessage signal to the global ScriptEngines these various messages
     auto scriptEngines = DependencyManager::get<ScriptEngines>().data();
-    connect(newEngine.data(), &ScriptEngine::printedMessage, scriptEngines, &ScriptEngines::onPrintedMessage);
-    connect(newEngine.data(), &ScriptEngine::errorMessage, scriptEngines, &ScriptEngines::onErrorMessage);
-    connect(newEngine.data(), &ScriptEngine::warningMessage, scriptEngines, &ScriptEngines::onWarningMessage);
-    connect(newEngine.data(), &ScriptEngine::infoMessage, scriptEngines, &ScriptEngines::onInfoMessage);
+    connect(newManager.get(), &ScriptManager::printedMessage, scriptEngines, &ScriptEngines::onPrintedMessage);
+    connect(newManager.get(), &ScriptManager::errorMessage, scriptEngines, &ScriptEngines::onErrorMessage);
+    connect(newManager.get(), &ScriptManager::warningMessage, scriptEngines, &ScriptEngines::onWarningMessage);
+    connect(newManager.get(), &ScriptManager::infoMessage, scriptEngines, &ScriptEngines::onInfoMessage);
 
-    connect(newEngine.data(), &ScriptEngine::update, this, [this] {
+    connect(newManager.get(), &ScriptManager::update, this, [this] {
         _entityViewer.queryOctree();
         _entityViewer.getTree()->preUpdate();
         _entityViewer.getTree()->update();
     });
 
-    scriptEngines->runScriptInitializers(newEngine);
-    newEngine->runInThread();
-    auto newEngineSP = qSharedPointerCast<EntitiesScriptEngineProvider>(newEngine);
+    scriptEngines->runScriptInitializers(newManager);
+    newManager->runInThread();
+    std::shared_ptr<EntitiesScriptEngineProvider> newEngineSP = newManager;
     // On the entity script server, these are the same
     DependencyManager::get<EntityScriptingInterface>()->setPersistentEntitiesScriptEngine(newEngineSP);
     DependencyManager::get<EntityScriptingInterface>()->setNonPersistentEntitiesScriptEngine(newEngineSP);
 
-    if (_entitiesScriptEngine) {
-        disconnect(_entitiesScriptEngine.data(), &ScriptEngine::entityScriptDetailsUpdated,
+    if (_entitiesScriptManager) {
+        disconnect(_entitiesScriptManager.get(), &ScriptManager::entityScriptDetailsUpdated,
                    this, &EntityScriptServer::updateEntityPPS);
     }
 
-    _entitiesScriptEngine.swap(newEngine);
-    connect(_entitiesScriptEngine.data(), &ScriptEngine::entityScriptDetailsUpdated,
+    _entitiesScriptManager.swap(newManager);
+    connect(_entitiesScriptManager.get(), &ScriptManager::entityScriptDetailsUpdated,
             this, &EntityScriptServer::updateEntityPPS);
 }
 
 
 void EntityScriptServer::clear() {
     // unload and stop the engine
-    if (_entitiesScriptEngine) {
+    if (_entitiesScriptManager) {
         // do this here (instead of in deleter) to avoid marshalling unload signals back to this thread
-        _entitiesScriptEngine->unloadAllEntityScripts();
-        _entitiesScriptEngine->stop();
-        _entitiesScriptEngine->waitTillDoneRunning();
+        _entitiesScriptManager->unloadAllEntityScripts();
+        _entitiesScriptManager->stop();
+        _entitiesScriptManager->waitTillDoneRunning();
     }
 
     _entityViewer.clear();
@@ -503,8 +506,8 @@ void EntityScriptServer::clear() {
 }
 
 void EntityScriptServer::shutdownScriptEngine() {
-    if (_entitiesScriptEngine) {
-        _entitiesScriptEngine->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
+    if (_entitiesScriptManager) {
+        _entitiesScriptManager->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
     }
     _shuttingDown = true;
 
@@ -513,7 +516,7 @@ void EntityScriptServer::shutdownScriptEngine() {
     auto scriptEngines = DependencyManager::get<ScriptEngines>();
     scriptEngines->shutdownScripting();
 
-    _entitiesScriptEngine.clear();
+    _entitiesScriptManager.reset();
 
     auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
     // our entity tree is going to go away so tell that to the EntityScriptingInterface
@@ -531,8 +534,8 @@ void EntityScriptServer::addingEntity(const EntityItemID& entityID) {
 }
 
 void EntityScriptServer::deletingEntity(const EntityItemID& entityID) {
-    if (_entityViewer.getTree() && !_shuttingDown && _entitiesScriptEngine) {
-        _entitiesScriptEngine->unloadEntityScript(entityID, true);
+    if (_entityViewer.getTree() && !_shuttingDown && _entitiesScriptManager) {
+        _entitiesScriptManager->unloadEntityScript(entityID, true);
     }
 }
 
@@ -543,20 +546,20 @@ void EntityScriptServer::entityServerScriptChanging(const EntityItemID& entityID
 }
 
 void EntityScriptServer::checkAndCallPreload(const EntityItemID& entityID, bool forceRedownload) {
-    if (_entityViewer.getTree() && !_shuttingDown && _entitiesScriptEngine) {
+    if (_entityViewer.getTree() && !_shuttingDown && _entitiesScriptManager) {
 
         EntityItemPointer entity = _entityViewer.getTree()->findEntityByEntityItemID(entityID);
         EntityScriptDetails details;
-        bool isRunning = _entitiesScriptEngine->getEntityScriptDetails(entityID, details);
+        bool isRunning = _entitiesScriptManager->getEntityScriptDetails(entityID, details);
         if (entity && (forceRedownload || !isRunning || details.scriptText != entity->getServerScripts())) {
             if (isRunning) {
-                _entitiesScriptEngine->unloadEntityScript(entityID, true);
+                _entitiesScriptManager->unloadEntityScript(entityID, true);
             }
 
             QString scriptUrl = entity->getServerScripts();
             if (!scriptUrl.isEmpty()) {
                 scriptUrl = DependencyManager::get<ResourceManager>()->normalizeURL(scriptUrl);
-                _entitiesScriptEngine->loadEntityScript(entityID, scriptUrl, forceRedownload);
+                _entitiesScriptManager->loadEntityScript(entityID, scriptUrl, forceRedownload);
             }
         }
     }
@@ -573,9 +576,9 @@ void EntityScriptServer::sendStatsPacket() {
 
     QJsonObject scriptEngineStats;
     int numberRunningScripts = 0;
-    const auto scriptEngine = _entitiesScriptEngine;
-    if (scriptEngine) {
-        numberRunningScripts = scriptEngine->getNumRunningEntityScripts();
+    const auto scriptManager = _entitiesScriptManager;
+    if (scriptManager) {
+        numberRunningScripts = scriptManager->getNumRunningEntityScripts();
     }
     scriptEngineStats["number_running_scripts"] = numberRunningScripts;
     statsObject["script_engine_stats"] = scriptEngineStats;
diff --git a/assignment-client/src/scripts/EntityScriptServer.h b/assignment-client/src/scripts/EntityScriptServer.h
index b7929eb5af3..71d6340fae0 100644
--- a/assignment-client/src/scripts/EntityScriptServer.h
+++ b/assignment-client/src/scripts/EntityScriptServer.h
@@ -18,12 +18,14 @@
 #include <QtCore/QObject>
 #include <QtCore/QSharedPointer>
 #include <QtCore/QUuid>
+#include <QtCore/QSharedPointer>
 
 #include <EntityEditPacketSender.h>
 #include <plugins/CodecPlugin.h>
-#include <ScriptEngine.h>
 #include <SimpleEntitySimulation.h>
 #include <ThreadedAssignment.h>
+#include <ScriptManager.h>
+
 #include "../entities/EntityTreeHeadlessViewer.h"
 
 class EntityScriptServer : public ThreadedAssignment {
@@ -76,7 +78,7 @@ private slots:
     bool _shuttingDown { false };
 
     static int _entitiesScriptEngineCount;
-    ScriptEnginePointer _entitiesScriptEngine;
+    ScriptManagerPointer _entitiesScriptManager;
     SimpleEntitySimulationPointer _entitySimulation;
     EntityEditPacketSender _entityEditSender;
     EntityTreeHeadlessViewer _entityViewer;
diff --git a/domain-server/CMakeLists.txt b/domain-server/CMakeLists.txt
index a3a85684b4d..6f123f23612 100644
--- a/domain-server/CMakeLists.txt
+++ b/domain-server/CMakeLists.txt
@@ -25,6 +25,7 @@ symlink_or_copy_directory_beside_target(${_SHOULD_SYMLINK_RESOURCES} "${CMAKE_CU
 # link the shared hifi libraries
 include_hifi_library_headers(gpu)
 include_hifi_library_headers(graphics)
+include_hifi_library_headers(script-engine)
 link_hifi_libraries(embedded-webserver networking shared avatars octree)
 
 target_zlib()
diff --git a/interface/CMakeLists.txt b/interface/CMakeLists.txt
index 0462ba22143..8a2b57484e1 100644
--- a/interface/CMakeLists.txt
+++ b/interface/CMakeLists.txt
@@ -21,7 +21,7 @@ set(CUSTOM_INTERFACE_QRC_PATHS "")
 
 find_package(
   Qt5 COMPONENTS
-  Gui Widgets Multimedia Network Qml Quick Script Svg
+  Gui Widgets Multimedia Network Qml Quick Svg
   ${PLATFORM_QT_COMPONENTS}
   WebChannel WebSockets
 )
@@ -217,7 +217,7 @@ link_hifi_libraries(
   shared workload task octree ktx gpu gl procedural graphics graphics-scripting render
   pointers recording hfm model-serializers networking material-networking
   model-networking model-baker entities avatars
-  audio audio-client animation script-engine physics
+  audio audio-client animation physics
   render-utils entities-renderer avatars-renderer ui qml auto-updater midi
   controllers plugins image platform
   ui-plugins display-plugins input-plugins
@@ -227,6 +227,7 @@ link_hifi_libraries(
   ${PLATFORM_PLUGIN_LIBRARIES}
   shaders
 )
+include_hifi_library_headers(script-engine)
 
 # include the binary directory of render-utils for shader includes
 target_include_directories(${TARGET_NAME} PRIVATE "${CMAKE_BINARY_DIR}/libraries/render-utils")
@@ -291,7 +292,7 @@ endif ()
 target_link_libraries(
   ${TARGET_NAME}
   Qt5::Gui Qt5::Network Qt5::Multimedia Qt5::Widgets
-  Qt5::Qml Qt5::Quick Qt5::Script Qt5::Svg
+  Qt5::Qml Qt5::Quick Qt5::Svg
   Qt5::WebChannel
   ${PLATFORM_QT_LIBRARIES}
 )
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 5fee0112e38..92f2d770f21 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -130,15 +130,19 @@
 #include <plugins/SteamClientPlugin.h>
 #include <plugins/OculusPlatformPlugin.h>
 #include <plugins/InputConfiguration.h>
-#include <RecordingScriptingInterface.h>
+#include <Quat.h>
+#include <recording/RecordingScriptingInterface.h>
 #include <render/EngineStats.h>
 #include <SecondaryCamera.h>
 #include <ResourceCache.h>
 #include <ResourceRequest.h>
 #include <SandboxUtils.h>
 #include <SceneScriptingInterface.h>
-#include <ScriptEngines.h>
 #include <ScriptCache.h>
+#include <ScriptEngines.h>
+#include <ScriptEngineCast.h>
+#include <ScriptManager.h>
+#include <ScriptUUID.h>
 #include <ShapeEntityItem.h>
 #include <SoundCacheScriptingInterface.h>
 #include <ui/TabletScriptingInterface.h>
@@ -166,6 +170,7 @@
 #include <procedural/ProceduralMaterialCache.h>
 #include <procedural/ReferenceMaterial.h>
 #include "recording/ClipCache.h"
+#include <Vec3.h>
 
 #include "AudioClient.h"
 #include "audio/AudioScope.h"
@@ -861,7 +866,7 @@ bool setupEssentials(int& argc, char** argv, bool runningMarkerExisted) {
 #endif
     DependencyManager::set<DomainAccountManager>();
     DependencyManager::set<StatTracker>();
-    DependencyManager::set<ScriptEngines>(ScriptEngine::CLIENT_SCRIPT, defaultScriptsOverrideOption);
+    DependencyManager::set<ScriptEngines>(ScriptManager::CLIENT_SCRIPT, defaultScriptsOverrideOption);
     DependencyManager::set<Preferences>();
     DependencyManager::set<recording::Deck>();
     DependencyManager::set<recording::Recorder>();
@@ -1446,8 +1451,8 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer, bo
 
     {
         auto scriptEngines = DependencyManager::get<ScriptEngines>().data();
-        scriptEngines->registerScriptInitializer([this](ScriptEnginePointer engine) {
-            registerScriptEngineWithApplicationServices(engine);
+        scriptEngines->registerScriptInitializer([this](ScriptManagerPointer manager) {
+            registerScriptEngineWithApplicationServices(manager);
         });
 
         connect(scriptEngines, &ScriptEngines::scriptCountChanged, this, [this] {
@@ -5900,7 +5905,7 @@ void Application::loadAvatarScripts(const QVector<QString>& urls) {
         if (index < 0) {
             auto scriptEnginePointer = scriptEngines->loadScript(url, false);
             if (scriptEnginePointer) {
-                scriptEnginePointer->setType(ScriptEngine::Type::AVATAR);
+                scriptEnginePointer->setType(ScriptManager::Type::AVATAR);
             }
         }
     }
@@ -5911,7 +5916,7 @@ void Application::unloadAvatarScripts() {
     auto urls = scriptEngines->getRunningScripts();
     for (auto url : urls) {
         auto scriptEngine = scriptEngines->getScriptEngine(url);
-        if (scriptEngine->getType() == ScriptEngine::Type::AVATAR) {
+        if (scriptEngine->getType() == ScriptManager::Type::AVATAR) {
             scriptEngines->stopScript(url, false);
         }
     }
@@ -7501,9 +7506,10 @@ void Application::addingEntityWithCertificate(const QString& certificateID, cons
     ledger->updateLocation(certificateID, placeName);
 }
 
-void Application::registerScriptEngineWithApplicationServices(const ScriptEnginePointer& scriptEngine) {
+void Application::registerScriptEngineWithApplicationServices(const ScriptManagerPointer& scriptManager) {
 
-    scriptEngine->setEmitScriptUpdatesFunction([this]() {
+    auto scriptEngine = scriptManager->engine();
+    scriptManager->setEmitScriptUpdatesFunction([this]() {
         SharedNodePointer entityServerNode = DependencyManager::get<NodeList>()->soloNodeOfType(NodeType::EntityServer);
         return !entityServerNode || isPhysicsEnabled();
     });
@@ -7535,13 +7541,13 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
 
     ClipboardScriptingInterface* clipboardScriptable = new ClipboardScriptingInterface();
     scriptEngine->registerGlobalObject("Clipboard", clipboardScriptable);
-    connect(scriptEngine.data(), &ScriptEngine::finished, clipboardScriptable, &ClipboardScriptingInterface::deleteLater);
+    connect(scriptManager.get(), &ScriptManager::finished, clipboardScriptable, &ClipboardScriptingInterface::deleteLater);
 
     scriptEngine->registerGlobalObject("Overlays", &_overlays);
-    qScriptRegisterMetaType(scriptEngine.data(), RayToOverlayIntersectionResultToScriptValue,
+    scriptRegisterMetaType(scriptEngine.get(), RayToOverlayIntersectionResultToScriptValue,
                             RayToOverlayIntersectionResultFromScriptValue);
 
-    bool clientScript = scriptEngine->isClientScript();
+    bool clientScript = scriptManager->isClientScript();
 
 #if !defined(DISABLE_QML)
     scriptEngine->registerGlobalObject("OffscreenFlags", getOffscreenUI()->getFlags());
@@ -7556,13 +7562,13 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     }
 #endif
 
-    qScriptRegisterMetaType(scriptEngine.data(), wrapperToScriptValue<ToolbarProxy>, wrapperFromScriptValue<ToolbarProxy>);
-    qScriptRegisterMetaType(scriptEngine.data(),
+    scriptRegisterMetaType(scriptEngine.get(), wrapperToScriptValue<ToolbarProxy>, wrapperFromScriptValue<ToolbarProxy>);
+    scriptRegisterMetaType(scriptEngine.get(),
                             wrapperToScriptValue<ToolbarButtonProxy>, wrapperFromScriptValue<ToolbarButtonProxy>);
     scriptEngine->registerGlobalObject("Toolbars", DependencyManager::get<ToolbarScriptingInterface>().data());
 
-    qScriptRegisterMetaType(scriptEngine.data(), wrapperToScriptValue<TabletProxy>, wrapperFromScriptValue<TabletProxy>);
-    qScriptRegisterMetaType(scriptEngine.data(),
+    scriptRegisterMetaType(scriptEngine.get(), wrapperToScriptValue<TabletProxy>, wrapperFromScriptValue<TabletProxy>);
+    scriptRegisterMetaType(scriptEngine.get(),
                             wrapperToScriptValue<TabletButtonProxy>, wrapperFromScriptValue<TabletButtonProxy>);
     scriptEngine->registerGlobalObject("Tablet", DependencyManager::get<TabletScriptingInterface>().data());
     // FIXME remove these deprecated names for the tablet scripting interface
@@ -7613,12 +7619,12 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     scriptEngine->registerGlobalObject("Account", AccountServicesScriptingInterface::getInstance()); // DEPRECATED - TO BE REMOVED
     scriptEngine->registerGlobalObject("GlobalServices", AccountServicesScriptingInterface::getInstance()); // DEPRECATED - TO BE REMOVED
     scriptEngine->registerGlobalObject("AccountServices", AccountServicesScriptingInterface::getInstance());
-    qScriptRegisterMetaType(scriptEngine.data(), DownloadInfoResultToScriptValue, DownloadInfoResultFromScriptValue);
+    scriptRegisterMetaType(scriptEngine.get(), DownloadInfoResultToScriptValue, DownloadInfoResultFromScriptValue);
 
     scriptEngine->registerGlobalObject("AvatarManager", DependencyManager::get<AvatarManager>().data());
 
     scriptEngine->registerGlobalObject("LODManager", DependencyManager::get<LODManager>().data());
-    qScriptRegisterMetaType(scriptEngine.data(), worldDetailQualityToScriptValue, worldDetailQualityFromScriptValue);
+    scriptRegisterMetaType(scriptEngine.get(), worldDetailQualityToScriptValue, worldDetailQualityFromScriptValue);
 
     scriptEngine->registerGlobalObject("Keyboard", DependencyManager::get<KeyboardScriptingInterface>().data());
     scriptEngine->registerGlobalObject("Performance", new PerformanceScriptingInterface());
@@ -7633,7 +7639,7 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     scriptEngine->registerGlobalObject("Render", RenderScriptingInterface::getInstance());
     scriptEngine->registerGlobalObject("Workload", _gameWorkload._engine->getConfiguration().get());
 
-    GraphicsScriptingInterface::registerMetaTypes(scriptEngine.data());
+    GraphicsScriptingInterface::registerMetaTypes(scriptEngine.get());
     scriptEngine->registerGlobalObject("Graphics", DependencyManager::get<GraphicsScriptingInterface>().data());
 
     scriptEngine->registerGlobalObject("ScriptDiscoveryService", DependencyManager::get<ScriptEngines>().data());
@@ -7645,11 +7651,11 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     scriptEngine->registerGlobalObject("GooglePoly", DependencyManager::get<GooglePolyScriptingInterface>().data());
 
     if (auto steamClient = PluginManager::getInstance()->getSteamClientPlugin()) {
-        scriptEngine->registerGlobalObject("Steam", new SteamScriptingInterface(scriptEngine.data(), steamClient.get()));
+        scriptEngine->registerGlobalObject("Steam", new SteamScriptingInterface(scriptManager.get(), steamClient.get()));
     }
     auto scriptingInterface = DependencyManager::get<controller::ScriptingInterface>();
     scriptEngine->registerGlobalObject("Controller", scriptingInterface.data());
-    UserInputMapper::registerControllerTypes(scriptEngine.data());
+    UserInputMapper::registerControllerTypes(scriptEngine.get());
 
     auto recordingInterface = DependencyManager::get<RecordingScriptingInterface>();
     scriptEngine->registerGlobalObject("Recording", recordingInterface.data());
@@ -7665,18 +7671,18 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     scriptEngine->registerGlobalObject("HifiAbout", AboutUtil::getInstance());  // Deprecated.
     scriptEngine->registerGlobalObject("ResourceRequestObserver", DependencyManager::get<ResourceRequestObserver>().data());
 
-    registerInteractiveWindowMetaType(scriptEngine.data());
+    registerInteractiveWindowMetaType(scriptEngine.get());
 
     auto pickScriptingInterface = DependencyManager::get<PickScriptingInterface>();
-    pickScriptingInterface->registerMetaTypes(scriptEngine.data());
+    pickScriptingInterface->registerMetaTypes(scriptEngine.get());
 
     // connect this script engines printedMessage signal to the global ScriptEngines these various messages
     auto scriptEngines = DependencyManager::get<ScriptEngines>().data();
-    connect(scriptEngine.data(), &ScriptEngine::printedMessage, scriptEngines, &ScriptEngines::onPrintedMessage);
-    connect(scriptEngine.data(), &ScriptEngine::errorMessage, scriptEngines, &ScriptEngines::onErrorMessage);
-    connect(scriptEngine.data(), &ScriptEngine::warningMessage, scriptEngines, &ScriptEngines::onWarningMessage);
-    connect(scriptEngine.data(), &ScriptEngine::infoMessage, scriptEngines, &ScriptEngines::onInfoMessage);
-    connect(scriptEngine.data(), &ScriptEngine::clearDebugWindow, scriptEngines, &ScriptEngines::onClearDebugWindow);
+    connect(scriptManager.get(), &ScriptManager::printedMessage, scriptEngines, &ScriptEngines::onPrintedMessage);
+    connect(scriptManager.get(), &ScriptManager::errorMessage, scriptEngines, &ScriptEngines::onErrorMessage);
+    connect(scriptManager.get(), &ScriptManager::warningMessage, scriptEngines, &ScriptEngines::onWarningMessage);
+    connect(scriptManager.get(), &ScriptManager::infoMessage, scriptEngines, &ScriptEngines::onInfoMessage);
+    connect(scriptManager.get(), &ScriptManager::clearDebugWindow, scriptEngines, &ScriptEngines::onClearDebugWindow);
 
 }
 
diff --git a/interface/src/Application.h b/interface/src/Application.h
index 215473ddfbc..50a31ebc7c6 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -14,6 +14,7 @@
 #define hifi_Application_h
 
 #include <functional>
+#include <memory>
 
 #include <QtCore/QHash>
 #include <QtCore/QPointer>
@@ -21,11 +22,13 @@
 #include <QtCore/QSharedPointer>
 #include <QtCore/QStringList>
 #include <QtQuick/QQuickItem>
+#include <QtCore/QSharedPointer>
 
 #include <QtGui/QImage>
 
 #include <QtWidgets/QApplication>
 
+#include <AvatarHashMap.h>
 #include <ThreadHelpers.h>
 #include <AbstractScriptingServicesInterface.h>
 #include <AbstractViewStateInterface.h>
@@ -40,7 +43,6 @@
 #include <PhysicsEngine.h>
 #include <plugins/Forward.h>
 #include <ui-plugins/PluginContainer.h>
-#include <ScriptEngine.h>
 #include <ShapeManager.h>
 #include <SimpleMovingAverage.h>
 #include <StDev.h>
@@ -89,6 +91,8 @@ class MainWindow;
 class AssetUpload;
 class CompositorHelper;
 class AudioInjector;
+class ScriptEngine;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
 
 namespace controller {
     class StateController;
@@ -244,7 +248,7 @@ class Application : public QApplication,
     NodeToOctreeSceneStats* getOcteeSceneStats() { return &_octreeServerSceneStats; }
 
     virtual controller::ScriptingInterface* getControllerScriptingInterface() { return _controllerScriptingInterface; }
-    virtual void registerScriptEngineWithApplicationServices(const ScriptEnginePointer& scriptEngine) override;
+    virtual void registerScriptEngineWithApplicationServices(const ScriptManagerPointer& scriptManager) override;
 
     virtual void copyCurrentViewFrustum(ViewFrustum& viewOut) const override { copyDisplayViewFrustum(viewOut); }
     virtual QThread* getMainThread() override { return thread(); }
diff --git a/interface/src/AvatarBookmarks.cpp b/interface/src/AvatarBookmarks.cpp
index f5d7eadc4d0..35ac531c810 100644
--- a/interface/src/AvatarBookmarks.cpp
+++ b/interface/src/AvatarBookmarks.cpp
@@ -49,12 +49,12 @@ void addAvatarEntities(const QVariantList& avatarEntities) {
     EntitySimulationPointer entitySimulation = entityTree->getSimulation();
     PhysicalEntitySimulationPointer physicalEntitySimulation = std::static_pointer_cast<PhysicalEntitySimulation>(entitySimulation);
     EntityEditPacketSender* entityPacketSender = physicalEntitySimulation->getPacketSender();
-    QScriptEngine scriptEngine;
+    ScriptEnginePointer scriptEngine = newScriptEngine();
     for (int index = 0; index < avatarEntities.count(); index++) {
         const QVariantMap& avatarEntityProperties = avatarEntities.at(index).toMap();
         QVariant variantProperties = avatarEntityProperties["properties"];
         QVariantMap asMap = variantProperties.toMap();
-        QScriptValue scriptProperties = variantMapToScriptValue(asMap, scriptEngine);
+        ScriptValue scriptProperties = variantMapToScriptValue(asMap, *scriptEngine);
         EntityItemProperties entityProperties;
         EntityItemPropertiesFromScriptValueIgnoreReadOnly(scriptProperties, entityProperties);
 
@@ -298,7 +298,7 @@ QVariantMap AvatarBookmarks::getAvatarDataToBookmark() {
     EntityTreePointer entityTree = treeRenderer ? treeRenderer->getTree() : nullptr;
 
     if (entityTree) {
-        QScriptEngine scriptEngine;
+        ScriptEnginePointer scriptEngine = newScriptEngine();
         auto avatarEntities = myAvatar->getAvatarEntityDataNonDefault();
         for (auto entityID : avatarEntities.keys()) {
             auto entity = entityTree->findEntityByID(entityID);
@@ -318,7 +318,7 @@ QVariantMap AvatarBookmarks::getAvatarDataToBookmark() {
             desiredProperties -= PROP_JOINT_TRANSLATIONS;
 
             EntityItemProperties entityProperties = entity->getProperties(desiredProperties);
-            QScriptValue scriptProperties = EntityItemPropertiesToScriptValue(&scriptEngine, entityProperties);
+            ScriptValue scriptProperties = EntityItemPropertiesToScriptValue(scriptEngine.get(), entityProperties);
             avatarEntityData["properties"] = scriptProperties.toVariant();
             wearableEntities.append(QVariant(avatarEntityData));
         }
diff --git a/interface/src/LODManager.cpp b/interface/src/LODManager.cpp
index 1c6ef387f3a..3acd4f47819 100644
--- a/interface/src/LODManager.cpp
+++ b/interface/src/LODManager.cpp
@@ -426,13 +426,14 @@ WorldDetailQuality LODManager::getWorldDetailQuality() const {
     return qApp->isHMDMode() ? _hmdWorldDetailQuality : _desktopWorldDetailQuality;
 }
 
-QScriptValue worldDetailQualityToScriptValue(QScriptEngine* engine, const WorldDetailQuality& worldDetailQuality) {
-    return worldDetailQuality;
+ScriptValue worldDetailQualityToScriptValue(ScriptEngine* engine, const WorldDetailQuality& worldDetailQuality) {
+    return engine->newValue(worldDetailQuality);
 }
 
-void worldDetailQualityFromScriptValue(const QScriptValue& object, WorldDetailQuality& worldDetailQuality) {
+bool worldDetailQualityFromScriptValue(const ScriptValue& object, WorldDetailQuality& worldDetailQuality) {
     worldDetailQuality = 
         static_cast<WorldDetailQuality>(std::min(std::max(object.toInt32(), (int)WORLD_DETAIL_LOW), (int)WORLD_DETAIL_HIGH));
+    return true;
 }
 
 void LODManager::setLODQualityLevel(float quality) {
diff --git a/interface/src/LODManager.h b/interface/src/LODManager.h
index 419ca9cddcc..afebe9d7747 100644
--- a/interface/src/LODManager.h
+++ b/interface/src/LODManager.h
@@ -22,7 +22,9 @@
 #include <PIDController.h>
 #include <SimpleMovingAverage.h>
 #include <render/Args.h>
+#include <ScriptValue.h>
 
+class ScriptEngine;
 
 /*@jsdoc
  * <p>The world detail quality rendered.</p>
@@ -380,7 +382,7 @@ class LODManager : public QObject, public Dependency {
     glm::vec4 _pidOutputs{ 0.0f };
 };
 
-QScriptValue worldDetailQualityToScriptValue(QScriptEngine* engine, const WorldDetailQuality& worldDetailQuality);
-void worldDetailQualityFromScriptValue(const QScriptValue& object, WorldDetailQuality& worldDetailQuality);
+ScriptValue worldDetailQualityToScriptValue(ScriptEngine* engine, const WorldDetailQuality& worldDetailQuality);
+bool worldDetailQualityFromScriptValue(const ScriptValue& object, WorldDetailQuality& worldDetailQuality);
 
 #endif // hifi_LODManager_h
diff --git a/interface/src/Menu.cpp b/interface/src/Menu.cpp
index aa116a9ce52..5d21896753c 100644
--- a/interface/src/Menu.cpp
+++ b/interface/src/Menu.cpp
@@ -22,6 +22,7 @@
 #include <thread>
 
 #include <AddressManager.h>
+#include <AssetClient.h>
 #include <AudioClient.h>
 #include <CrashHelpers.h>
 #include <DependencyManager.h>
diff --git a/interface/src/PerformanceManager.cpp b/interface/src/PerformanceManager.cpp
index 190071724a6..090c72d07e8 100644
--- a/interface/src/PerformanceManager.cpp
+++ b/interface/src/PerformanceManager.cpp
@@ -19,7 +19,11 @@
 
 PerformanceManager::PerformanceManager()
 {
-    setPerformancePreset((PerformancePreset) _performancePresetSetting.get());
+    static std::once_flag registry_flag;
+    std::call_once(registry_flag, [] {
+        qRegisterMetaType<PerformanceManager::PerformancePreset>("PerformanceManager::PerformancePreset");
+    });
+    setPerformancePreset((PerformancePreset)_performancePresetSetting.get());
 }
 
 void PerformanceManager::setupPerformancePresetSettings(bool evaluatePlatformTier) {
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 943845bda75..191770642bf 100755
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -13,7 +13,8 @@
 
 #include <string>
 
-#include <QScriptEngine>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 
 #include "AvatarLogging.h"
 
@@ -735,8 +736,8 @@ AvatarSharedPointer AvatarManager::getAvatarBySessionID(const QUuid& sessionID)
 }
 
 RayToAvatarIntersectionResult AvatarManager::findRayIntersection(const PickRay& ray,
-                                                                 const QScriptValue& avatarIdsToInclude,
-                                                                 const QScriptValue& avatarIdsToDiscard,
+                                                                 const ScriptValue& avatarIdsToInclude,
+                                                                 const ScriptValue& avatarIdsToDiscard,
                                                                  bool pickAgainstMesh) {
     QVector<EntityItemID> avatarsToInclude = qVectorEntityItemIDFromScriptValue(avatarIdsToInclude);
     QVector<EntityItemID> avatarsToDiscard = qVectorEntityItemIDFromScriptValue(avatarIdsToDiscard);
@@ -980,7 +981,7 @@ float AvatarManager::getAvatarSortCoefficient(const QString& name) {
 }
 
 // HACK
-void AvatarManager::setAvatarSortCoefficient(const QString& name, const QScriptValue& value) {
+void AvatarManager::setAvatarSortCoefficient(const QString& name, const ScriptValue& value) {
     bool somethingChanged = false;
     if (value.isNumber()) {
         float numericalValue = (float)value.toNumber();
diff --git a/interface/src/avatar/AvatarManager.h b/interface/src/avatar/AvatarManager.h
index f7e951d21d2..e2784008211 100644
--- a/interface/src/avatar/AvatarManager.h
+++ b/interface/src/avatar/AvatarManager.h
@@ -26,13 +26,14 @@
 #include <AudioInjectorManager.h>
 #include <workload/Space.h>
 #include <EntitySimulation.h> // for SetOfEntities
+#include <ScriptValue.h>
 
 #include "AvatarMotionState.h"
 #include "DetailedMotionState.h"
 #include "MyAvatar.h"
 #include "OtherAvatar.h"
 
-
+class ScriptEngine;
 using SortedAvatar = std::pair<float, std::shared_ptr<Avatar>>;
 
 /*@jsdoc 
@@ -94,7 +95,7 @@ class AvatarManager : public AvatarHashMap {
      */
 
     /// Registers the script types associated with the avatar manager.
-    static void registerMetaTypes(QScriptEngine* engine);
+    static void registerMetaTypes(ScriptEngine* engine);
 
     virtual ~AvatarManager();
 
@@ -185,8 +186,8 @@ class AvatarManager : public AvatarHashMap {
      * }
      */
     Q_INVOKABLE RayToAvatarIntersectionResult findRayIntersection(const PickRay& ray,
-                                                                  const QScriptValue& avatarIdsToInclude = QScriptValue(),
-                                                                  const QScriptValue& avatarIdsToDiscard = QScriptValue(),
+                                                                  const ScriptValue& avatarIdsToInclude = ScriptValue(),
+                                                                  const ScriptValue& avatarIdsToDiscard = ScriptValue(),
                                                                   bool pickAgainstMesh = true);
     /*@jsdoc
      * @function AvatarManager.findRayIntersectionVector
@@ -229,7 +230,7 @@ class AvatarManager : public AvatarHashMap {
      * @param {number} value - Value.
      * @deprecated This function is deprecated and will be removed.
      */
-    Q_INVOKABLE void setAvatarSortCoefficient(const QString& name, const QScriptValue& value);
+    Q_INVOKABLE void setAvatarSortCoefficient(const QString& name, const ScriptValue& value);
 
     /*@jsdoc
      * Gets PAL (People Access List) data for one or more avatars. Using this method is faster than iterating over each avatar 
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 0d650bf2e73..3fdcc6f1d34 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -43,13 +43,15 @@
 #include <udt/PacketHeaders.h>
 #include <PathUtils.h>
 #include <PerfStat.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
 #include <SharedUtil.h>
 #include <SoundCache.h>
 #include <ModelEntityItem.h>
 #include <TextRenderer3D.h>
 #include <UserActivityLogger.h>
 #include <recording/Recorder.h>
-#include <RecordingScriptingInterface.h>
+#include <recording/RecordingScriptingInterface.h>
 #include <RenderableModelEntityItem.h>
 #include <VariantMapToScriptValue.h>
 #include <NetworkingConstants.h>
@@ -377,8 +379,6 @@ MyAvatar::MyAvatar(QThread* thread) :
 
 MyAvatar::~MyAvatar() {
     _lookAtTargetAvatar.reset();
-    delete _scriptEngine;
-    _scriptEngine = nullptr;
     if (_addAvatarEntitiesToTreeTimer.isActive()) {
         _addAvatarEntitiesToTreeTimer.stop();
     }
@@ -438,18 +438,18 @@ void MyAvatar::enableHandTouchForID(const QUuid& entityID) {
 }
 
 void MyAvatar::registerMetaTypes(ScriptEnginePointer engine) {
-    QScriptValue value = engine->newQObject(this, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects);
+    ScriptValue value = engine->newQObject(this, ScriptEngine::QtOwnership);
     engine->globalObject().setProperty("MyAvatar", value);
 
-    QScriptValue driveKeys = engine->newObject();
+    ScriptValue driveKeys = engine->newObject();
     auto metaEnum = QMetaEnum::fromType<DriveKeys>();
     for (int i = 0; i < MAX_DRIVE_KEYS; ++i) {
         driveKeys.setProperty(metaEnum.key(i), metaEnum.value(i));
     }
     engine->globalObject().setProperty("DriveKeys", driveKeys);
 
-    qScriptRegisterMetaType(engine.data(), audioListenModeToScriptValue, audioListenModeFromScriptValue);
-    qScriptRegisterMetaType(engine.data(), driveKeysToScriptValue, driveKeysFromScriptValue);
+    scriptRegisterMetaType(engine.get(), audioListenModeToScriptValue, audioListenModeFromScriptValue);
+    scriptRegisterMetaType(engine.get(), driveKeysToScriptValue, driveKeysFromScriptValue);
 }
 
 void MyAvatar::setOrientationVar(const QVariant& newOrientationVar) {
@@ -2061,7 +2061,7 @@ void MyAvatar::avatarEntityDataToJson(QJsonObject& root) const {
 
 void MyAvatar::loadData() {
     if (!_scriptEngine) {
-        _scriptEngine = new QScriptEngine();
+        _scriptEngine = newScriptEngine();
     }
     getHead()->setBasePitch(_headPitchSetting.get());
 
@@ -2669,8 +2669,7 @@ QVariantList MyAvatar::getAvatarEntitiesVariant() {
             EntityItemProperties entityProperties = entity->getProperties(desiredProperties);
             {
                 std::lock_guard<std::mutex> guard(_scriptEngineLock);
-                QScriptValue scriptProperties;
-                scriptProperties = EntityItemPropertiesToScriptValue(_scriptEngine, entityProperties);
+                ScriptValue scriptProperties = EntityItemPropertiesToScriptValue(_scriptEngine.get(), entityProperties);
                 avatarEntityData["properties"] = scriptProperties.toVariant();
             }
             avatarEntitiesData.append(QVariant(avatarEntityData));
@@ -5702,20 +5701,22 @@ void MyAvatar::setAudioListenerMode(AudioListenerMode audioListenerMode) {
     }
 }
 
-QScriptValue audioListenModeToScriptValue(QScriptEngine* engine, const AudioListenerMode& audioListenerMode) {
-    return audioListenerMode;
+ScriptValue audioListenModeToScriptValue(ScriptEngine* engine, const AudioListenerMode& audioListenerMode) {
+    return engine->newValue(audioListenerMode);
 }
 
-void audioListenModeFromScriptValue(const QScriptValue& object, AudioListenerMode& audioListenerMode) {
+bool audioListenModeFromScriptValue(const ScriptValue& object, AudioListenerMode& audioListenerMode) {
     audioListenerMode = static_cast<AudioListenerMode>(object.toUInt16());
+    return true;
 }
 
-QScriptValue driveKeysToScriptValue(QScriptEngine* engine, const MyAvatar::DriveKeys& driveKeys) {
-    return driveKeys;
+ScriptValue driveKeysToScriptValue(ScriptEngine* engine, const MyAvatar::DriveKeys& driveKeys) {
+    return engine->newValue(driveKeys);
 }
 
-void driveKeysFromScriptValue(const QScriptValue& object, MyAvatar::DriveKeys& driveKeys) {
+bool driveKeysFromScriptValue(const ScriptValue& object, MyAvatar::DriveKeys& driveKeys) {
     driveKeys = static_cast<MyAvatar::DriveKeys>(object.toUInt16());
+    return true;
 }
 
 
diff --git a/interface/src/avatar/MyAvatar.h b/interface/src/avatar/MyAvatar.h
index 8b5ffa233a4..80b6de7bcb3 100644
--- a/interface/src/avatar/MyAvatar.h
+++ b/interface/src/avatar/MyAvatar.h
@@ -14,6 +14,7 @@
 #define hifi_MyAvatar_h
 
 #include <bitset>
+#include <memory>
 
 #include <glm/glm.hpp>
 
@@ -27,10 +28,10 @@
 #include <EntityItem.h>
 #include <ThreadSafeValueCache.h>
 #include <Rig.h>
-#include <ScriptEngine.h>
 #include <SettingHandle.h>
 #include <Sound.h>
 #include <shared/Camera.h>
+#include <ScriptValue.h>
 
 #include "AtRestDetector.h"
 #include "MyCharacterController.h"
@@ -40,6 +41,8 @@ class AvatarActionHold;
 class ModelItemID;
 class MyHead;
 class DetailedMotionState;
+class ScriptEngine;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
 
 /*@jsdoc
  * <p>Locomotion control types.</p>
@@ -869,7 +872,7 @@ class MyAvatar : public Avatar {
      *     MyAvatar.removeAnimationStateHandler(handler);
      * }, 100);
      */
-    Q_INVOKABLE QScriptValue addAnimationStateHandler(QScriptValue handler, QScriptValue propertiesList) { return _skeletonModel->getRig().addAnimationStateHandler(handler, propertiesList); }
+    Q_INVOKABLE ScriptValue addAnimationStateHandler(const ScriptValue& handler, const ScriptValue& propertiesList) { return _skeletonModel->getRig().addAnimationStateHandler(handler, propertiesList); }
 
     /*@jsdoc
      * Removes an animation state handler function.
@@ -877,7 +880,7 @@ class MyAvatar : public Avatar {
      * @param {number} handler - The ID of the animation state handler function to remove.
      */
     // Removes a handler previously added by addAnimationStateHandler.
-    Q_INVOKABLE void removeAnimationStateHandler(QScriptValue handler) { _skeletonModel->getRig().removeAnimationStateHandler(handler); }
+    Q_INVOKABLE void removeAnimationStateHandler(const ScriptValue& handler) { _skeletonModel->getRig().removeAnimationStateHandler(handler); }
 
 
     /*@jsdoc
@@ -3098,7 +3101,7 @@ private slots:
     //
     // keep a ScriptEngine around so we don't have to instantiate on the fly (these are very slow to create/delete)
     mutable std::mutex _scriptEngineLock;
-    QScriptEngine* _scriptEngine { nullptr };
+    ScriptEnginePointer _scriptEngine { nullptr };
     bool _needToSaveAvatarEntitySettings { false };
 
     bool _reactionTriggers[NUM_AVATAR_TRIGGER_REACTIONS] { false, false };
@@ -3115,11 +3118,11 @@ private slots:
     QTimer _addAvatarEntitiesToTreeTimer;
 };
 
-QScriptValue audioListenModeToScriptValue(QScriptEngine* engine, const AudioListenerMode& audioListenerMode);
-void audioListenModeFromScriptValue(const QScriptValue& object, AudioListenerMode& audioListenerMode);
+ScriptValue audioListenModeToScriptValue(ScriptEngine* engine, const AudioListenerMode& audioListenerMode);
+bool audioListenModeFromScriptValue(const ScriptValue& object, AudioListenerMode& audioListenerMode);
 
-QScriptValue driveKeysToScriptValue(QScriptEngine* engine, const MyAvatar::DriveKeys& driveKeys);
-void driveKeysFromScriptValue(const QScriptValue& object, MyAvatar::DriveKeys& driveKeys);
+ScriptValue driveKeysToScriptValue(ScriptEngine* engine, const MyAvatar::DriveKeys& driveKeys);
+bool driveKeysFromScriptValue(const ScriptValue& object, MyAvatar::DriveKeys& driveKeys);
 
 bool isWearableEntity(const EntityItemPointer& entity);
 
diff --git a/interface/src/commerce/QmlCommerce.cpp b/interface/src/commerce/QmlCommerce.cpp
index 47105e0f3a2..78363b077d1 100644
--- a/interface/src/commerce/QmlCommerce.cpp
+++ b/interface/src/commerce/QmlCommerce.cpp
@@ -374,7 +374,7 @@ bool QmlCommerce::installApp(const QString& itemHref, const bool& alsoOpenImmedi
         // Don't try to re-load (install) a script if it's already running
         QStringList runningScripts = DependencyManager::get<ScriptEngines>()->getRunningScripts();
         if (!runningScripts.contains(scriptUrl)) {
-            if ((DependencyManager::get<ScriptEngines>()->loadScript(scriptUrl.trimmed())).isNull()) {
+            if (!(DependencyManager::get<ScriptEngines>()->loadScript(scriptUrl.trimmed()))) {
                 qCDebug(commerce) << "Couldn't load script.";
                 return false;
             }
diff --git a/interface/src/raypick/LaserPointerScriptingInterface.cpp b/interface/src/raypick/LaserPointerScriptingInterface.cpp
index 16fe65a989f..ed5fd2ecb69 100644
--- a/interface/src/raypick/LaserPointerScriptingInterface.cpp
+++ b/interface/src/raypick/LaserPointerScriptingInterface.cpp
@@ -11,14 +11,14 @@
 
 #include "LaserPointerScriptingInterface.h"
 
-#include "RegisteredMetaTypes.h"
 #include "PointerScriptingInterface.h"
+#include <ScriptValueUtils.h>
 
-void LaserPointerScriptingInterface::setIgnoreItems(unsigned int uid, const QScriptValue& ignoreItems) const {
+void LaserPointerScriptingInterface::setIgnoreItems(unsigned int uid, const ScriptValue& ignoreItems) const {
     DependencyManager::get<PointerManager>()->setIgnoreItems(uid, qVectorQUuidFromScriptValue(ignoreItems));
 }
 
-void LaserPointerScriptingInterface::setIncludeItems(unsigned int uid, const QScriptValue& includeItems) const {
+void LaserPointerScriptingInterface::setIncludeItems(unsigned int uid, const ScriptValue& includeItems) const {
     DependencyManager::get<PointerManager>()->setIncludeItems(uid, qVectorQUuidFromScriptValue(includeItems));
 }
 
diff --git a/interface/src/raypick/LaserPointerScriptingInterface.h b/interface/src/raypick/LaserPointerScriptingInterface.h
index ab3bca57d62..fe70509a0c8 100644
--- a/interface/src/raypick/LaserPointerScriptingInterface.h
+++ b/interface/src/raypick/LaserPointerScriptingInterface.h
@@ -16,6 +16,8 @@
 #include "DependencyManager.h"
 #include <PointerManager.h>
 
+class ScriptValue;
+
 class LaserPointerScriptingInterface : public QObject, public Dependency {
     Q_OBJECT
     SINGLETON_DEPENDENCY
@@ -113,7 +115,7 @@ class LaserPointerScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pointer.
      * @param {Uuid[]} ignoreItems - A list of IDs to ignore.
      */
-    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const QScriptValue& ignoreEntities) const;
+    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const ScriptValue& ignoreEntities) const;
 
     /*@jsdoc
      * Sets a list of entity and avatar IDs that a pointer should include during intersection, instead of intersecting with
@@ -122,7 +124,7 @@ class LaserPointerScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pointer.
      * @param {Uuid[]} includeItems - A list of IDs to include.
      */
-    Q_INVOKABLE void setIncludeItems(unsigned int uid, const QScriptValue& includeEntities) const;
+    Q_INVOKABLE void setIncludeItems(unsigned int uid, const ScriptValue& includeEntities) const;
 
 
     /*@jsdoc
diff --git a/interface/src/raypick/PathPointer.cpp b/interface/src/raypick/PathPointer.cpp
index 8a1675cfe18..b0223888aa4 100644
--- a/interface/src/raypick/PathPointer.cpp
+++ b/interface/src/raypick/PathPointer.cpp
@@ -12,6 +12,7 @@
 
 #include <DependencyManager.h>
 #include <PickManager.h>
+#include <Quat.h>
 #include "PickScriptingInterface.h"
 #include "RayPick.h"
 
diff --git a/interface/src/raypick/PickScriptingInterface.cpp b/interface/src/raypick/PickScriptingInterface.cpp
index e7777efe458..b5ef887f628 100644
--- a/interface/src/raypick/PickScriptingInterface.cpp
+++ b/interface/src/raypick/PickScriptingInterface.cpp
@@ -29,6 +29,8 @@
 #include "EntityTransformNode.h"
 
 #include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptValueUtils.h>
 
 static const float WEB_TOUCH_Y_OFFSET = 0.105f;  // how far forward (or back with a negative number) to slide stylus in hand
 static const glm::vec3 TIP_OFFSET = glm::vec3(0.0f, StylusPick::WEB_STYLUS_LENGTH - WEB_TOUCH_Y_OFFSET, 0.0f);
@@ -425,11 +427,11 @@ void PickScriptingInterface::setPrecisionPicking(unsigned int uid, bool precisio
     DependencyManager::get<PickManager>()->setPrecisionPicking(uid, precisionPicking);
 }
 
-void PickScriptingInterface::setIgnoreItems(unsigned int uid, const QScriptValue& ignoreItems) {
+void PickScriptingInterface::setIgnoreItems(unsigned int uid, const ScriptValue& ignoreItems) {
     DependencyManager::get<PickManager>()->setIgnoreItems(uid, qVectorQUuidFromScriptValue(ignoreItems));
 }
 
-void PickScriptingInterface::setIncludeItems(unsigned int uid, const QScriptValue& includeItems) {
+void PickScriptingInterface::setIncludeItems(unsigned int uid, const ScriptValue& includeItems) {
     DependencyManager::get<PickManager>()->setIncludeItems(uid, qVectorQUuidFromScriptValue(includeItems));
 }
 
@@ -445,23 +447,24 @@ bool PickScriptingInterface::isMouse(unsigned int uid) {
     return DependencyManager::get<PickManager>()->isMouse(uid);
 }
 
-QScriptValue pickTypesToScriptValue(QScriptEngine* engine, const PickQuery::PickType& pickType) {
-    return pickType;
+ScriptValue pickTypesToScriptValue(ScriptEngine* engine, const PickQuery::PickType& pickType) {
+    return engine->newValue(pickType);
 }
 
-void pickTypesFromScriptValue(const QScriptValue& object, PickQuery::PickType& pickType) {
+bool pickTypesFromScriptValue(const ScriptValue& object, PickQuery::PickType& pickType) {
     pickType = static_cast<PickQuery::PickType>(object.toUInt16());
+    return true;
 }
 
-void PickScriptingInterface::registerMetaTypes(QScriptEngine* engine) {
-    QScriptValue pickTypes = engine->newObject();
+void PickScriptingInterface::registerMetaTypes(ScriptEngine* engine) {
+    ScriptValue pickTypes = engine->newObject();
     auto metaEnum = QMetaEnum::fromType<PickQuery::PickType>();
     for (int i = 0; i < PickQuery::PickType::NUM_PICK_TYPES; ++i) {
         pickTypes.setProperty(metaEnum.key(i), metaEnum.value(i));
     }
     engine->globalObject().setProperty("PickType", pickTypes);
 
-    qScriptRegisterMetaType(engine, pickTypesToScriptValue, pickTypesFromScriptValue);
+    scriptRegisterMetaType(engine, pickTypesToScriptValue, pickTypesFromScriptValue);
 }
 
 unsigned int PickScriptingInterface::getPerFrameTimeBudget() const {
diff --git a/interface/src/raypick/PickScriptingInterface.h b/interface/src/raypick/PickScriptingInterface.h
index 72470b42ee1..8afe5c45d35 100644
--- a/interface/src/raypick/PickScriptingInterface.h
+++ b/interface/src/raypick/PickScriptingInterface.h
@@ -15,6 +15,9 @@
 #include <Pick.h>
 #include <PickFilter.h>
 
+class ScriptEngine;
+class ScriptValue;
+
 /*@jsdoc
  * The <code>Picks</code> API lets you create and manage objects for repeatedly calculating intersections.
  *
@@ -103,7 +106,7 @@ class PickScriptingInterface : public QObject, public Dependency {
     SINGLETON_DEPENDENCY
 
 public:
-    void registerMetaTypes(QScriptEngine* engine);
+    void registerMetaTypes(ScriptEngine* engine);
 
     /*@jsdoc
      * Creates a new pick. Different {@link PickType}s use different properties, and within one PickType the properties you 
@@ -245,7 +248,7 @@ class PickScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pick.
      * @param {Uuid[]} ignoreItems - The list of IDs to ignore.
      */
-    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const QScriptValue& ignoreItems);
+    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const ScriptValue& ignoreItems);
 
     /*@jsdoc
      * Sets a list of entity and avatar IDs that a pick should include during intersection, instead of intersecting with 
@@ -255,7 +258,7 @@ class PickScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pick.
      * @param {Uuid[]} includeItems - The list of IDs to include.
      */
-    Q_INVOKABLE void setIncludeItems(unsigned int uid, const QScriptValue& includeItems);
+    Q_INVOKABLE void setIncludeItems(unsigned int uid, const ScriptValue& includeItems);
 
     /*@jsdoc
      * Checks if a pick is associated with the left hand: a ray or parabola pick with <code>joint</code> property set to 
diff --git a/interface/src/raypick/PointerScriptingInterface.cpp b/interface/src/raypick/PointerScriptingInterface.cpp
index 0b4c399d3bd..259fbf428d8 100644
--- a/interface/src/raypick/PointerScriptingInterface.cpp
+++ b/interface/src/raypick/PointerScriptingInterface.cpp
@@ -12,6 +12,8 @@
 #include <GLMHelpers.h>
 #include <shared/QtHelpers.h>
 
+#include <ScriptValueUtils.h>
+
 #include "Application.h"
 #include "PickManager.h"
 #include "LaserPointer.h"
@@ -23,11 +25,11 @@ static const glm::quat X_ROT_NEG_90{ 0.70710678f, -0.70710678f, 0.0f, 0.0f };
 static const glm::vec3 DEFAULT_POSITION_OFFSET{0.0f, 0.0f, -StylusPick::WEB_STYLUS_LENGTH / 2.0f};
 static const glm::vec3 DEFAULT_MODEL_DIMENSIONS{0.01f, 0.01f, StylusPick::WEB_STYLUS_LENGTH};
 
-void PointerScriptingInterface::setIgnoreItems(unsigned int uid, const QScriptValue& ignoreItems) const {
+void PointerScriptingInterface::setIgnoreItems(unsigned int uid, const ScriptValue& ignoreItems) const {
     DependencyManager::get<PointerManager>()->setIgnoreItems(uid, qVectorQUuidFromScriptValue(ignoreItems));
 }
 
-void PointerScriptingInterface::setIncludeItems(unsigned int uid, const QScriptValue& includeItems) const {
+void PointerScriptingInterface::setIncludeItems(unsigned int uid, const ScriptValue& includeItems) const {
     DependencyManager::get<PointerManager>()->setIncludeItems(uid, qVectorQUuidFromScriptValue(includeItems));
 }
 
diff --git a/interface/src/raypick/PointerScriptingInterface.h b/interface/src/raypick/PointerScriptingInterface.h
index 58439f221d4..836a86b7bdd 100644
--- a/interface/src/raypick/PointerScriptingInterface.h
+++ b/interface/src/raypick/PointerScriptingInterface.h
@@ -15,6 +15,8 @@
 #include <PointerManager.h>
 #include <Pick.h>
 
+class ScriptValue;
+
 /*@jsdoc
  * The <code>Pointers</code> API lets you create, manage, and visually represent objects for repeatedly calculating 
  * intersections with avatars, entities, and overlays. Pointers can also be configured to generate events on entities and 
@@ -365,7 +367,7 @@ class PointerScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pointer.
      * @param {Uuid[]} ignoreItems - A list of IDs to ignore.
      */
-    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const QScriptValue& ignoreEntities) const;
+    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const ScriptValue& ignoreEntities) const;
 
     /*@jsdoc
      * Sets a list of entity and avatar IDs that a pointer should include during intersection, instead of intersecting with 
@@ -375,7 +377,7 @@ class PointerScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the pointer.
      * @param {Uuid[]} includeItems - A list of IDs to include.
      */
-    Q_INVOKABLE void setIncludeItems(unsigned int uid, const QScriptValue& includeEntities) const;
+    Q_INVOKABLE void setIncludeItems(unsigned int uid, const ScriptValue& includeEntities) const;
 
 
     /*@jsdoc
diff --git a/interface/src/raypick/RayPickScriptingInterface.cpp b/interface/src/raypick/RayPickScriptingInterface.cpp
index a837121e6ad..6371632368a 100644
--- a/interface/src/raypick/RayPickScriptingInterface.cpp
+++ b/interface/src/raypick/RayPickScriptingInterface.cpp
@@ -15,6 +15,7 @@
 #include "GLMHelpers.h"
 
 #include <PickManager.h>
+#include <ScriptValueUtils.h>
 
 unsigned int RayPickScriptingInterface::createRayPick(const QVariant& properties) {
     return DependencyManager::get<PickScriptingInterface>()->createPick(PickQuery::PickType::Ray, properties);
@@ -45,11 +46,11 @@ void RayPickScriptingInterface::setPrecisionPicking(unsigned int uid, bool preci
     DependencyManager::get<PickManager>()->setPrecisionPicking(uid, precisionPicking);
 }
 
-void RayPickScriptingInterface::setIgnoreItems(unsigned int uid, const QScriptValue& ignoreItems) {
+void RayPickScriptingInterface::setIgnoreItems(unsigned int uid, const ScriptValue& ignoreItems) {
     DependencyManager::get<PickManager>()->setIgnoreItems(uid, qVectorQUuidFromScriptValue(ignoreItems));
 }
 
-void RayPickScriptingInterface::setIncludeItems(unsigned int uid, const QScriptValue& includeItems) {
+void RayPickScriptingInterface::setIncludeItems(unsigned int uid, const ScriptValue& includeItems) {
     DependencyManager::get<PickManager>()->setIncludeItems(uid, qVectorQUuidFromScriptValue(includeItems));
 }
 
diff --git a/interface/src/raypick/RayPickScriptingInterface.h b/interface/src/raypick/RayPickScriptingInterface.h
index 0aed9e4bdfa..acc11111c76 100644
--- a/interface/src/raypick/RayPickScriptingInterface.h
+++ b/interface/src/raypick/RayPickScriptingInterface.h
@@ -18,6 +18,8 @@
 
 #include "PickScriptingInterface.h"
 
+class ScriptValue;
+
 /*@jsdoc
  * The <code>RayPick</code> API is a subset of the {@link Picks} API, as used for ray picks.
  *
@@ -121,7 +123,7 @@ class RayPickScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the ray pick.
      * @param {Uuid[]} ignoreItems - The list of IDs to ignore.
      */
-    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const QScriptValue& ignoreEntities);
+    Q_INVOKABLE void setIgnoreItems(unsigned int uid, const ScriptValue& ignoreEntities);
 
     /*@jsdoc
      * Sets a list of entity and avatar IDs that a ray pick should include during intersection, instead of intersecting with 
@@ -130,7 +132,7 @@ class RayPickScriptingInterface : public QObject, public Dependency {
      * @param {number} id - The ID of the ray pick.
      * @param {Uuid[]} includeItems - The list of IDs to include.
      */
-    Q_INVOKABLE void setIncludeItems(unsigned int uid, const QScriptValue& includeEntities);
+    Q_INVOKABLE void setIncludeItems(unsigned int uid, const ScriptValue& includeEntities);
 
 
     /*@jsdoc
diff --git a/interface/src/scripting/AccountServicesScriptingInterface.cpp b/interface/src/scripting/AccountServicesScriptingInterface.cpp
index 87aacad631b..042cb25978c 100644
--- a/interface/src/scripting/AccountServicesScriptingInterface.cpp
+++ b/interface/src/scripting/AccountServicesScriptingInterface.cpp
@@ -123,10 +123,10 @@ DownloadInfoResult::DownloadInfoResult() :
  * @property {number[]} downloading - The download percentage remaining of each asset currently downloading.
  * @property {number} pending - The number of assets pending download.
  */
-QScriptValue DownloadInfoResultToScriptValue(QScriptEngine* engine, const DownloadInfoResult& result) {
-    QScriptValue object = engine->newObject();
+ScriptValue DownloadInfoResultToScriptValue(ScriptEngine* engine, const DownloadInfoResult& result) {
+    ScriptValue object = engine->newObject();
 
-    QScriptValue array = engine->newArray(result.downloading.count());
+    ScriptValue array = engine->newArray(result.downloading.count());
     for (int i = 0; i < result.downloading.count(); i += 1) {
         array.setProperty(i, result.downloading[i]);
     }
@@ -136,7 +136,7 @@ QScriptValue DownloadInfoResultToScriptValue(QScriptEngine* engine, const Downlo
     return object;
 }
 
-void DownloadInfoResultFromScriptValue(const QScriptValue& object, DownloadInfoResult& result) {
+bool DownloadInfoResultFromScriptValue(const ScriptValue& object, DownloadInfoResult& result) {
     QList<QVariant> downloading = object.property("downloading").toVariant().toList();
     result.downloading.clear();
     for (int i = 0; i < downloading.count(); i += 1) {
@@ -144,6 +144,7 @@ void DownloadInfoResultFromScriptValue(const QScriptValue& object, DownloadInfoR
     }
 
     result.pending = object.property("pending").toVariant().toFloat();
+    return true;
 }
 
 DownloadInfoResult AccountServicesScriptingInterface::getDownloadInfo() {
diff --git a/interface/src/scripting/AccountServicesScriptingInterface.h b/interface/src/scripting/AccountServicesScriptingInterface.h
index 723622523ce..2d13891fa57 100644
--- a/interface/src/scripting/AccountServicesScriptingInterface.h
+++ b/interface/src/scripting/AccountServicesScriptingInterface.h
@@ -13,14 +13,14 @@
 #define hifi_AccountServicesScriptingInterface_h
 
 #include <QObject>
-#include <QScriptContext>
-#include <QScriptEngine>
-#include <QScriptValue>
 #include <QString>
 #include <QStringList>
 
 #include <AccountManager.h>
 #include <DiscoverabilityManager.h>
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class DownloadInfoResult {
 public:
@@ -31,8 +31,8 @@ class DownloadInfoResult {
 
 Q_DECLARE_METATYPE(DownloadInfoResult)
 
-QScriptValue DownloadInfoResultToScriptValue(QScriptEngine* engine, const DownloadInfoResult& result);
-void DownloadInfoResultFromScriptValue(const QScriptValue& object, DownloadInfoResult& result);
+ScriptValue DownloadInfoResultToScriptValue(ScriptEngine* engine, const DownloadInfoResult& result);
+bool DownloadInfoResultFromScriptValue(const ScriptValue& object, DownloadInfoResult& result);
 
 class AccountServicesScriptingInterface : public QObject {
     Q_OBJECT
diff --git a/interface/src/scripting/AssetMappingsScriptingInterface.cpp b/interface/src/scripting/AssetMappingsScriptingInterface.cpp
index 5b90474d233..0c80d0384df 100644
--- a/interface/src/scripting/AssetMappingsScriptingInterface.cpp
+++ b/interface/src/scripting/AssetMappingsScriptingInterface.cpp
@@ -11,7 +11,6 @@
 
 #include "AssetMappingsScriptingInterface.h"
 
-#include <QtScript/QScriptEngine>
 #include <QtCore/QFile>
 #include <QtCore/QThread>
 
diff --git a/interface/src/scripting/AssetMappingsScriptingInterface.h b/interface/src/scripting/AssetMappingsScriptingInterface.h
index b27a72fbd0f..bc0676b1bca 100644
--- a/interface/src/scripting/AssetMappingsScriptingInterface.h
+++ b/interface/src/scripting/AssetMappingsScriptingInterface.h
@@ -15,14 +15,12 @@
 #define hifi_AssetMappingsScriptingInterface_h
 
 #include <QtCore/QObject>
-#include <QtScript/QScriptValue>
 
 #include <AssetClient.h>
 #include <QSortFilterProxyModel>
 
 #include "DependencyManager.h"
 
-
 class AssetMappingModel : public QStandardItemModel {
     Q_OBJECT
     Q_PROPERTY(bool autoRefreshEnabled READ isAutoRefreshEnabled WRITE setAutoRefreshEnabled)
diff --git a/interface/src/scripting/DesktopScriptingInterface.h b/interface/src/scripting/DesktopScriptingInterface.h
index 28d5f8d4446..68eb27c7d06 100644
--- a/interface/src/scripting/DesktopScriptingInterface.h
+++ b/interface/src/scripting/DesktopScriptingInterface.h
@@ -13,7 +13,6 @@
 #define hifi_DesktopScriptingInterface_h
 
 #include <QObject>
-#include <QtScript/QScriptValue>
 
 #include <DependencyManager.h>
 
diff --git a/interface/src/scripting/HMDScriptingInterface.cpp b/interface/src/scripting/HMDScriptingInterface.cpp
index 79c0452a452..609037b7149 100644
--- a/interface/src/scripting/HMDScriptingInterface.cpp
+++ b/interface/src/scripting/HMDScriptingInterface.cpp
@@ -11,14 +11,15 @@
 
 #include "HMDScriptingInterface.h"
 
-#include <QtScript/QScriptContext>
-
 #include <shared/QtHelpers.h>
 #include <avatar/AvatarManager.h>
 #include <display-plugins/DisplayPlugin.h>
 #include <display-plugins/CompositorHelper.h>
 #include <OffscreenUi.h>
 #include <plugins/PluginUtils.h>
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
 #include <QUuid>
 
 #include "Application.h"
@@ -151,23 +152,23 @@ bool HMDScriptingInterface::getAwayStateWhenFocusLostInVREnabled() {
 }
 
 
-QScriptValue HMDScriptingInterface::getHUDLookAtPosition2D(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue HMDScriptingInterface::getHUDLookAtPosition2D(ScriptContext* context, ScriptEngine* engine) {
     glm::vec3 hudIntersection;
     auto instance = DependencyManager::get<HMDScriptingInterface>();
     if (instance->getHUDLookAtPosition3D(hudIntersection)) {
         glm::vec2 overlayPos = qApp->getApplicationCompositor().overlayFromSphereSurface(hudIntersection);
-        return qScriptValueFromValue<glm::vec2>(engine, overlayPos);
+        return scriptValueFromValue<glm::vec2>(engine, overlayPos);
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue HMDScriptingInterface::getHUDLookAtPosition3D(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue HMDScriptingInterface::getHUDLookAtPosition3D(ScriptContext* context, ScriptEngine* engine) {
     glm::vec3 result;
     auto instance = DependencyManager::get<HMDScriptingInterface>();
     if (instance->getHUDLookAtPosition3D(result)) {
-        return qScriptValueFromValue<glm::vec3>(engine, result);
+        return scriptValueFromValue<glm::vec3>(engine, result);
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
 bool HMDScriptingInterface::getHUDLookAtPosition3D(glm::vec3& result) const {
diff --git a/interface/src/scripting/HMDScriptingInterface.h b/interface/src/scripting/HMDScriptingInterface.h
index 7790c482fab..ad0bcad1002 100644
--- a/interface/src/scripting/HMDScriptingInterface.h
+++ b/interface/src/scripting/HMDScriptingInterface.h
@@ -14,15 +14,15 @@
 
 #include <atomic>
 
-#include <QtScript/QScriptValue>
-class QScriptContext;
-class QScriptEngine;
-
 #include <GLMHelpers.h>
 #include <DependencyManager.h>
 #include <display-plugins/AbstractHMDScriptingInterface.h>
 
 #include <QReadWriteLock>
+#include <ScriptValue.h>
+
+class ScriptContext;
+class ScriptEngine;
 
 /*@jsdoc
  * The <code>HMD</code> API provides access to the HMD used in VR display mode.
@@ -442,14 +442,14 @@ class HMDScriptingInterface : public AbstractHMDScriptingInterface, public Depen
      * @function HMD.getHUDLookAtPosition2D
      * @returns {Vec2} The position on the HUD overlay that your HMD is looking at, in pixels.
      */
-    static QScriptValue getHUDLookAtPosition2D(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue getHUDLookAtPosition2D(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Gets the position on the HUD overlay that your HMD is looking at, in world coordinates.
      * @function HMD.getHUDLookAtPosition3D
      * @returns {Vec3} The position on the HUD overlay the your HMD is looking at, in world coordinates.
      */
-    static QScriptValue getHUDLookAtPosition3D(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue getHUDLookAtPosition3D(ScriptContext* context, ScriptEngine* engine);
 
     bool isMounted() const override;
 
diff --git a/interface/src/scripting/PerformanceScriptingInterface.cpp b/interface/src/scripting/PerformanceScriptingInterface.cpp
index ec56e833238..fb4561aea8d 100644
--- a/interface/src/scripting/PerformanceScriptingInterface.cpp
+++ b/interface/src/scripting/PerformanceScriptingInterface.cpp
@@ -16,6 +16,8 @@ std::once_flag PerformanceScriptingInterface::registry_flag;
 PerformanceScriptingInterface::PerformanceScriptingInterface() {
     std::call_once(registry_flag, [] {
         qmlRegisterType<PerformanceScriptingInterface>("PerformanceEnums", 1, 0, "PerformanceEnums");
+        qRegisterMetaType<PerformanceScriptingInterface::PerformancePreset>("PerformanceScriptingInterface::PerformancePreset");
+        qRegisterMetaType<PerformanceScriptingInterface::RefreshRateProfile>("PerformanceScriptingInterface::RefreshRateProfile");
     });
 }
 
diff --git a/interface/src/scripting/PlatformInfoScriptingInterface.h b/interface/src/scripting/PlatformInfoScriptingInterface.h
index 71b54f95fd5..8391c404d83 100644
--- a/interface/src/scripting/PlatformInfoScriptingInterface.h
+++ b/interface/src/scripting/PlatformInfoScriptingInterface.h
@@ -12,8 +12,6 @@
 #include <platform/Profiler.h>
 #include <QtCore/QObject>
 
-class QScriptValue;
-
 /*@jsdoc
  * The <code>PlatformInfo</code> API provides information about the hardware platform being used.
  *
diff --git a/interface/src/scripting/RenderScriptingInterface.cpp b/interface/src/scripting/RenderScriptingInterface.cpp
index 5ecb1a6e43a..aec7ae3b4cd 100644
--- a/interface/src/scripting/RenderScriptingInterface.cpp
+++ b/interface/src/scripting/RenderScriptingInterface.cpp
@@ -20,6 +20,7 @@ std::once_flag RenderScriptingInterface::registry_flag;
 RenderScriptingInterface::RenderScriptingInterface() {
     std::call_once(registry_flag, [] {
         qmlRegisterType<RenderScriptingInterface>("RenderEnums", 1, 0, "RenderEnums");
+        qRegisterMetaType<RenderScriptingInterface::RenderMethod>("RenderScriptingInterface::RenderMethod");
     });
 }
 
diff --git a/interface/src/scripting/SettingsScriptingInterface.cpp b/interface/src/scripting/SettingsScriptingInterface.cpp
index 13eddddb1f5..9ad2ef187c9 100644
--- a/interface/src/scripting/SettingsScriptingInterface.cpp
+++ b/interface/src/scripting/SettingsScriptingInterface.cpp
@@ -47,7 +47,7 @@ void SettingsScriptingInterface::setValue(const QString& setting, const QVariant
         }
     }
     // Make a deep-copy of the string.
-    // Dangling pointers can occur with QStrings that are implicitly shared from a QScriptEngine.
+    // Dangling pointers can occur with QStrings that are implicitly shared from a ScriptEngine.
     QString deepCopy = QString::fromUtf16(setting.utf16());
     Setting::Handle<QVariant>(deepCopy).set(value);
     emit valueChanged(setting, value);
diff --git a/interface/src/scripting/TestScriptingInterface.cpp b/interface/src/scripting/TestScriptingInterface.cpp
index 53630b3eede..2985ae6e50e 100644
--- a/interface/src/scripting/TestScriptingInterface.cpp
+++ b/interface/src/scripting/TestScriptingInterface.cpp
@@ -16,6 +16,7 @@
 #include <DependencyManager.h>
 #include <MainWindow.h>
 #include <OffscreenUi.h>
+#include <ScriptValue.h>
 #include <StatTracker.h>
 #include <Trace.h>
 
@@ -153,7 +154,7 @@ void TestScriptingInterface::savePhysicsSimulationStats(QString originalPath) {
     qApp->saveNextPhysicsStats(path);
 }
 
-void TestScriptingInterface::profileRange(const QString& name, QScriptValue fn) {
+void TestScriptingInterface::profileRange(const QString& name, const ScriptValue& fn) {
     PROFILE_RANGE(script, name);
     fn.call();
 }
diff --git a/interface/src/scripting/TestScriptingInterface.h b/interface/src/scripting/TestScriptingInterface.h
index 329f2a87c14..b5305d1df2a 100644
--- a/interface/src/scripting/TestScriptingInterface.h
+++ b/interface/src/scripting/TestScriptingInterface.h
@@ -12,8 +12,7 @@
 
 #include <functional>
 #include <QtCore/QObject>
-
-class QScriptValue;
+#include <ScriptValue.h>
 
 class TestScriptingInterface : public QObject {
     Q_OBJECT
@@ -127,7 +126,7 @@ public slots:
     * @param {string} name - Name used to reference the function
     * @param {function} function - Function to profile
     */
-    Q_INVOKABLE void profileRange(const QString& name, QScriptValue function);
+    Q_INVOKABLE void profileRange(const QString& name, const ScriptValue& function);
 
     /*@jsdoc
     * Clear all caches (menu command Reload Content)
diff --git a/interface/src/scripting/WindowScriptingInterface.cpp b/interface/src/scripting/WindowScriptingInterface.cpp
index e594ecd5369..cdc3fdb09a5 100644
--- a/interface/src/scripting/WindowScriptingInterface.cpp
+++ b/interface/src/scripting/WindowScriptingInterface.cpp
@@ -14,7 +14,7 @@
 #include <QClipboard>
 #include <QtCore/QDir>
 #include <QMessageBox>
-#include <QScriptValue>
+#include <ScriptValue.h>
 #include <QtGui/QDesktopServices>
 #include <shared/QtHelpers.h>
 #include <SettingHandle.h>
@@ -76,8 +76,8 @@ WindowScriptingInterface::~WindowScriptingInterface() {
     _messageBoxes.clear();
 }
 
-QScriptValue WindowScriptingInterface::hasFocus() {
-    return qApp->hasFocus();
+ScriptValue WindowScriptingInterface::hasFocus() {
+    return engine()->newValue(qApp->hasFocus());
 }
 
 void WindowScriptingInterface::setFocus() {
@@ -96,28 +96,29 @@ void WindowScriptingInterface::raise() {
 
 /// Display an alert box
 /// \param const QString& message message to display
-/// \return QScriptValue::UndefinedValue
+/// \return ScriptValue::UndefinedValue
 void WindowScriptingInterface::alert(const QString& message) {
     OffscreenUi::asyncWarning("", message, QMessageBox::Ok, QMessageBox::Ok);
 }
 
 /// Display a confirmation box with the options 'Yes' and 'No'
 /// \param const QString& message message to display
-/// \return QScriptValue `true` if 'Yes' was clicked, `false` otherwise
-QScriptValue WindowScriptingInterface::confirm(const QString& message) {
-    return QScriptValue((QMessageBox::Yes == OffscreenUi::question("", message, QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes)));
+/// \return ScriptValue `true` if 'Yes' was clicked, `false` otherwise
+ScriptValue WindowScriptingInterface::confirm(const QString& message) {
+    return engine()->newValue((QMessageBox::Yes == OffscreenUi::question("", message, QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes)));
 }
 
 /// Display a prompt with a text box
 /// \param const QString& message message to display
 /// \param const QString& defaultText default text in the text box
-/// \return QScriptValue string text value in text box if the dialog was accepted, `null` otherwise.
-QScriptValue WindowScriptingInterface::prompt(const QString& message, const QString& defaultText) {
+/// \return ScriptValue string text value in text box if the dialog was accepted, `null` otherwise.
+ScriptValue WindowScriptingInterface::prompt(const QString& message, const QString& defaultText) {
     QString result = OffscreenUi::getText(nullptr, "", message, QLineEdit::Normal, defaultText);
-    if (QScriptValue(result).equals("")) {
-        return QScriptValue::NullValue;
+    auto sResult = engine()->newValue(result);
+    if (sResult.equals(engine()->newValue(""))) {
+        return engine()->nullValue();
     }
-    return QScriptValue(result);
+    return sResult;
 }
 
 /// Display a prompt with a text box
@@ -217,8 +218,8 @@ void WindowScriptingInterface::ensureReticleVisible() const {
 /// working directory.
 /// \param const QString& title title of the window
 /// \param const QString& directory directory to start the directory browser at
-/// \return QScriptValue file path as a string if one was selected, otherwise `QScriptValue::NullValue`
-QScriptValue WindowScriptingInterface::browseDir(const QString& title, const QString& directory) {
+/// \return ScriptValue file path as a string if one was selected, otherwise `ScriptValue::NullValue`
+ScriptValue WindowScriptingInterface::browseDir(const QString& title, const QString& directory) {
     ensureReticleVisible();
     QString path = directory;
     if (path.isEmpty()) {
@@ -231,7 +232,7 @@ QScriptValue WindowScriptingInterface::browseDir(const QString& title, const QSt
     if (!result.isEmpty()) {
         setPreviousBrowseLocation(QFileInfo(result).absolutePath());
     }
-    return result.isEmpty() ? QScriptValue::NullValue : QScriptValue(result);
+    return result.isEmpty() ? engine()->nullValue() : engine()->newValue(result);
 }
 
 /// Display a "browse to directory" dialog.  If `directory` is an invalid file or directory the browser will start at the current
@@ -261,8 +262,8 @@ void WindowScriptingInterface::browseDirAsync(const QString& title, const QStrin
 /// \param const QString& title title of the window
 /// \param const QString& directory directory to start the file browser at
 /// \param const QString& nameFilter filter to filter filenames by - see `QFileDialog`
-/// \return QScriptValue file path as a string if one was selected, otherwise `QScriptValue::NullValue`
-QScriptValue WindowScriptingInterface::browse(const QString& title, const QString& directory, const QString& nameFilter) {
+/// \return ScriptValue file path as a string if one was selected, otherwise `ScriptValue::NullValue`
+ScriptValue WindowScriptingInterface::browse(const QString& title, const QString& directory, const QString& nameFilter) {
     ensureReticleVisible();
     QString path = directory;
     if (path.isEmpty()) {
@@ -275,7 +276,7 @@ QScriptValue WindowScriptingInterface::browse(const QString& title, const QStrin
     if (!result.isEmpty()) {
         setPreviousBrowseLocation(QFileInfo(result).absolutePath());
     }
-    return result.isEmpty() ? QScriptValue::NullValue : QScriptValue(result);
+    return result.isEmpty() ? engine()->nullValue() : engine()->newValue(result);
 }
 
 /// Display an open file dialog.  If `directory` is an invalid file or directory the browser will start at the current
@@ -308,8 +309,8 @@ void WindowScriptingInterface::browseAsync(const QString& title, const QString&
 /// \param const QString& title title of the window
 /// \param const QString& directory directory to start the file browser at
 /// \param const QString& nameFilter filter to filter filenames by - see `QFileDialog`
-/// \return QScriptValue file path as a string if one was selected, otherwise `QScriptValue::NullValue`
-QScriptValue WindowScriptingInterface::save(const QString& title, const QString& directory, const QString& nameFilter) {
+/// \return ScriptValue file path as a string if one was selected, otherwise `ScriptValue::NullValue`
+ScriptValue WindowScriptingInterface::save(const QString& title, const QString& directory, const QString& nameFilter) {
     ensureReticleVisible();
     QString path = directory;
     if (path.isEmpty()) {
@@ -322,7 +323,7 @@ QScriptValue WindowScriptingInterface::save(const QString& title, const QString&
     if (!result.isEmpty()) {
         setPreviousBrowseLocation(QFileInfo(result).absolutePath());
     }
-    return result.isEmpty() ? QScriptValue::NullValue : QScriptValue(result);
+    return result.isEmpty() ? engine()->nullValue() : engine()->newValue(result);
 }
 
 /// Display a save file dialog.  If `directory` is an invalid file or directory the browser will start at the current
@@ -355,8 +356,8 @@ void WindowScriptingInterface::saveAsync(const QString& title, const QString& di
 /// \param const QString& title title of the window
 /// \param const QString& directory directory to start the asset browser at
 /// \param const QString& nameFilter filter to filter asset names by - see `QFileDialog`
-/// \return QScriptValue asset path as a string if one was selected, otherwise `QScriptValue::NullValue`
-QScriptValue WindowScriptingInterface::browseAssets(const QString& title, const QString& directory, const QString& nameFilter) {
+/// \return ScriptValue asset path as a string if one was selected, otherwise `ScriptValue::NullValue`
+ScriptValue WindowScriptingInterface::browseAssets(const QString& title, const QString& directory, const QString& nameFilter) {
     ensureReticleVisible();
     QString path = directory;
     if (path.isEmpty()) {
@@ -372,7 +373,7 @@ QScriptValue WindowScriptingInterface::browseAssets(const QString& title, const
     if (!result.isEmpty()) {
         setPreviousBrowseAssetLocation(QFileInfo(result).absolutePath());
     }
-    return result.isEmpty() ? QScriptValue::NullValue : QScriptValue(result);
+    return result.isEmpty() ? engine()->nullValue() : engine()->newValue(result);
 }
 
 /// Display a select asset dialog that lets the user select an asset from the Asset Server.  If `directory` is an invalid
diff --git a/interface/src/scripting/WindowScriptingInterface.h b/interface/src/scripting/WindowScriptingInterface.h
index e7a2e809576..e3f78c0a4fd 100644
--- a/interface/src/scripting/WindowScriptingInterface.h
+++ b/interface/src/scripting/WindowScriptingInterface.h
@@ -17,10 +17,12 @@
 #include <QtCore/QObject>
 #include <QtCore/QString>
 #include <QtQuick/QQuickItem>
-#include <QtScript/QScriptValue>
 #include <QtWidgets/QMessageBox>
 
 #include <DependencyManager.h>
+#include <Scriptable.h>
+#include <ScriptValue.h>
+
 
 /*@jsdoc
  * The <code>Window</code> API provides various facilities not covered elsewhere, including: window dimensions, window focus, 
@@ -46,7 +48,7 @@
  * @property {location} location - Provides facilities for working with your current metaverse location.
  */
 
-class WindowScriptingInterface : public QObject, public Dependency {
+class WindowScriptingInterface : public QObject, protected Scriptable, public Dependency {
     Q_OBJECT
     Q_PROPERTY(int innerWidth READ getInnerWidth)
     Q_PROPERTY(int innerHeight READ getInnerHeight)
@@ -69,7 +71,7 @@ public slots:
      * @function Window.hasFocus
      * @returns {boolean} <code>true</code> if the Interface window has focus, <code>false</code> if it doesn't.
      */
-    QScriptValue hasFocus();
+    ScriptValue hasFocus();
 
     /*@jsdoc
      * Makes the Interface window have focus. On Windows, if Interface doesn't already have focus, the task bar icon flashes to 
@@ -104,7 +106,7 @@ public slots:
      * var answer = Window.confirm("Are you sure?");
      * print(answer);  // true or false
      */
-    QScriptValue confirm(const QString& message = "");
+    ScriptValue confirm(const QString& message = "");
 
     /*@jsdoc
      * Prompts the user to enter some text. Displays a modal dialog with a message and a text box, plus "OK" and "Cancel" 
@@ -121,7 +123,7 @@ public slots:
      *     print("User answer: " + answer);
      * }
      */
-    QScriptValue prompt(const QString& message, const QString& defaultText);
+    ScriptValue prompt(const QString& message, const QString& defaultText);
 
     /*@jsdoc
      * Prompts the user to enter some text. Displays a non-modal dialog with a message and a text box, plus "OK" and "Cancel" 
@@ -151,7 +153,7 @@ public slots:
      * var directory = Window.browseDir("Select Directory", Paths.resources);
      * print("Directory: " + directory);
      */
-    QScriptValue browseDir(const QString& title = "", const QString& directory = "");
+    ScriptValue browseDir(const QString& title = "", const QString& directory = "");
     
     /*@jsdoc
      * Prompts the user to choose a directory. Displays a non-modal dialog that navigates the directory tree. A
@@ -183,7 +185,7 @@ public slots:
      * var filename = Window.browse("Select Image File", Paths.resources, "Images (*.png *.jpg *.svg)");
      * print("File: " + filename);
      */
-    QScriptValue browse(const QString& title = "", const QString& directory = "",  const QString& nameFilter = "");
+    ScriptValue browse(const QString& title = "", const QString& directory = "",  const QString& nameFilter = "");
 
     /*@jsdoc
      * Prompts the user to choose a file. Displays a non-modal dialog that navigates the directory tree. A
@@ -219,7 +221,7 @@ public slots:
      * var filename = Window.save("Save to JSON file", Paths.resources, "*.json");
      * print("File: " + filename);
      */
-    QScriptValue save(const QString& title = "", const QString& directory = "",  const QString& nameFilter = "");
+    ScriptValue save(const QString& title = "", const QString& directory = "",  const QString& nameFilter = "");
 
     /*@jsdoc
      * Prompts the user to specify the path and name of a file to save to. Displays a non-modal dialog that navigates the
@@ -254,7 +256,7 @@ public slots:
      * var asset = Window.browseAssets("Select FBX File", "/", "*.fbx");
      * print("FBX file: " + asset);
      */
-    QScriptValue browseAssets(const QString& title = "", const QString& directory = "", const QString& nameFilter = "");
+    ScriptValue browseAssets(const QString& title = "", const QString& directory = "", const QString& nameFilter = "");
 
     /*@jsdoc
      * Prompts the user to choose an Asset Server item. Displays a non-modal dialog that navigates the tree of assets on the 
diff --git a/interface/src/ui/InteractiveWindow.cpp b/interface/src/ui/InteractiveWindow.cpp
index d1bdbb16523..cda66c5cf27 100644
--- a/interface/src/ui/InteractiveWindow.cpp
+++ b/interface/src/ui/InteractiveWindow.cpp
@@ -24,6 +24,8 @@
 #include <DependencyManager.h>
 #include <DockWidget.h>
 #include <RegisteredMetaTypes.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
 
 #include "OffscreenUi.h"
 #include "shared/QtHelpers.h"
@@ -91,18 +93,19 @@ static void dockWidgetDeleter(DockWidget* dockWidget) {
     dockWidget->deleteLater();
 }
 
-void registerInteractiveWindowMetaType(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, interactiveWindowPointerToScriptValue, interactiveWindowPointerFromScriptValue);
+void registerInteractiveWindowMetaType(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, interactiveWindowPointerToScriptValue, interactiveWindowPointerFromScriptValue);
 }
 
-QScriptValue interactiveWindowPointerToScriptValue(QScriptEngine* engine, const InteractiveWindowPointer& in) {
-    return engine->newQObject(in, QScriptEngine::ScriptOwnership);
+ScriptValue interactiveWindowPointerToScriptValue(ScriptEngine* engine, const InteractiveWindowPointer& in) {
+    return engine->newQObject(in, ScriptEngine::ScriptOwnership);
 }
 
-void interactiveWindowPointerFromScriptValue(const QScriptValue& object, InteractiveWindowPointer& out) {
+bool interactiveWindowPointerFromScriptValue(const ScriptValue& object, InteractiveWindowPointer& out) {
     if (const auto interactiveWindow = qobject_cast<InteractiveWindowPointer>(object.toQObject())) {
         out = interactiveWindow;
     }
+    return true;
 }
 
 void InteractiveWindow::forwardKeyPressEvent(int key, int modifiers) {
diff --git a/interface/src/ui/InteractiveWindow.h b/interface/src/ui/InteractiveWindow.h
index 744875fef52..9cce6944cbd 100644
--- a/interface/src/ui/InteractiveWindow.h
+++ b/interface/src/ui/InteractiveWindow.h
@@ -16,12 +16,14 @@
 
 #include <QtCore/QObject>
 #include <QtCore/QPointer>
-#include <QtScript/QScriptValue>
 #include <QQmlEngine>
 #include <ui/QmlWrapper.h>
 
 #include <glm/glm.hpp>
 #include <GLMHelpers.h>
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class QmlWindowProxy : public QmlWrapper {
     Q_OBJECT
@@ -408,10 +410,10 @@ protected slots:
 
 typedef InteractiveWindow* InteractiveWindowPointer;
 
-QScriptValue interactiveWindowPointerToScriptValue(QScriptEngine* engine, const InteractiveWindowPointer& in);
-void interactiveWindowPointerFromScriptValue(const QScriptValue& object, InteractiveWindowPointer& out);
+ScriptValue interactiveWindowPointerToScriptValue(ScriptEngine* engine, const InteractiveWindowPointer& in);
+bool interactiveWindowPointerFromScriptValue(const ScriptValue& object, InteractiveWindowPointer& out);
 
-void registerInteractiveWindowMetaType(QScriptEngine* engine);
+void registerInteractiveWindowMetaType(ScriptEngine* engine);
 
 Q_DECLARE_METATYPE(InteractiveWindowPointer)
 
diff --git a/interface/src/ui/JSConsole.cpp b/interface/src/ui/JSConsole.cpp
index ed4ee97780d..7d4fadab8e5 100644
--- a/interface/src/ui/JSConsole.cpp
+++ b/interface/src/ui/JSConsole.cpp
@@ -18,6 +18,8 @@
 #include <QStringListModel>
 #include <QListView>
 #include <QToolTip>
+#include <QtGui/QStandardItem>
+#include <QtGui/QStandardItemModel>
 
 #include <shared/QtHelpers.h>
 #include <ScriptEngines.h>
@@ -133,7 +135,7 @@ QStandardItemModel* JSConsole::getAutoCompleteModel(const QString& memberOf) {
     return model;
 }
 
-JSConsole::JSConsole(QWidget* parent, const ScriptEnginePointer& scriptEngine) :
+JSConsole::JSConsole(QWidget* parent, const ScriptManagerPointer& scriptManager) :
     QWidget(parent),
     _ui(new Ui::Console),
     _currentCommandInHistory(NO_CURRENT_HISTORY_COMMAND),
@@ -181,11 +183,11 @@ JSConsole::JSConsole(QWidget* parent, const ScriptEnginePointer& scriptEngine) :
     QObject::connect(_completer, static_cast<void(QCompleter::*)(const QModelIndex&)>(&QCompleter::highlighted), this,
         &JSConsole::highlightedCompletion);
 
-    setScriptEngine(scriptEngine);
+    setScriptManager(scriptManager);
 
     resizeTextInput();
 
-    connect(&_executeWatcher, &QFutureWatcher<QScriptValue>::finished, this, &JSConsole::commandFinished);
+    connect(&_executeWatcher, &QFutureWatcher<ScriptValue>::finished, this, &JSConsole::commandFinished);
 }
 
 void JSConsole::insertCompletion(const QModelIndex& completion) {
@@ -305,33 +307,33 @@ void JSConsole::highlightedCompletion(const QModelIndex& completion) {
 }
 
 JSConsole::~JSConsole() {
-    if (_scriptEngine) {
-        disconnect(_scriptEngine.data(), nullptr, this, nullptr);
-        _scriptEngine.reset();
+    if (_scriptManager) {
+        disconnect(_scriptManager.get(), nullptr, this, nullptr);
+        _scriptManager.reset();
     }
     delete _ui;
 }
 
-void JSConsole::setScriptEngine(const ScriptEnginePointer& scriptEngine) {
-    if (_scriptEngine == scriptEngine && scriptEngine != nullptr) {
+void JSConsole::setScriptManager(const ScriptManagerPointer& scriptManager) {
+    if (_scriptManager == scriptManager && scriptManager != nullptr) {
         return;
     }
-    if (_scriptEngine != nullptr) {
-        disconnect(_scriptEngine.data(), nullptr, this, nullptr);
-        _scriptEngine.reset();
+    if (_scriptManager != nullptr) {
+        disconnect(_scriptManager.get(), nullptr, this, nullptr);
+        _scriptManager.reset();
     }
 
     // if scriptEngine is nullptr then create one and keep track of it using _ownScriptEngine
-    if (scriptEngine.isNull()) {
-        _scriptEngine = DependencyManager::get<ScriptEngines>()->loadScript(_consoleFileName, false);
+    if (!scriptManager) {
+        _scriptManager = DependencyManager::get<ScriptEngines>()->loadScript(_consoleFileName, false);
     } else {
-        _scriptEngine = scriptEngine;
+        _scriptManager = scriptManager;
     }
 
-    connect(_scriptEngine.data(), &ScriptEngine::printedMessage, this, &JSConsole::handlePrint);
-    connect(_scriptEngine.data(), &ScriptEngine::infoMessage, this, &JSConsole::handleInfo);
-    connect(_scriptEngine.data(), &ScriptEngine::warningMessage, this, &JSConsole::handleWarning);
-    connect(_scriptEngine.data(), &ScriptEngine::errorMessage, this, &JSConsole::handleError);
+    connect(_scriptManager.get(), &ScriptManager::printedMessage, this, &JSConsole::handlePrint);
+    connect(_scriptManager.get(), &ScriptManager::infoMessage, this, &JSConsole::handleInfo);
+    connect(_scriptManager.get(), &ScriptManager::warningMessage, this, &JSConsole::handleWarning);
+    connect(_scriptManager.get(), &ScriptManager::errorMessage, this, &JSConsole::handleError);
 }
 
 void JSConsole::executeCommand(const QString& command) {
@@ -347,16 +349,15 @@ void JSConsole::executeCommand(const QString& command) {
 
     appendMessage(">", "<span style='" + COMMAND_STYLE + "'>" + command.toHtmlEscaped() + "</span>");
 
-    QWeakPointer<ScriptEngine> weakScriptEngine = _scriptEngine;
+    std::weak_ptr<ScriptManager> weakScriptManager = _scriptManager;
     auto consoleFileName = _consoleFileName;
-    QFuture<QScriptValue> future = QtConcurrent::run([weakScriptEngine, consoleFileName, command]()->QScriptValue{
-        QScriptValue result;
-        auto scriptEngine = weakScriptEngine.lock();
-        if (scriptEngine) {
-            BLOCKING_INVOKE_METHOD(scriptEngine.data(), "evaluate",
-                Q_RETURN_ARG(QScriptValue, result),
-                Q_ARG(const QString&, command),
-                Q_ARG(const QString&, consoleFileName));
+    QFuture<ScriptValue> future = QtConcurrent::run([weakScriptManager, consoleFileName, command]() -> ScriptValue {
+        ScriptValue result;
+        auto scriptManager = weakScriptManager.lock();
+        if (scriptManager) {
+            BLOCKING_INVOKE_METHOD(scriptManager.get(), [&scriptManager, &consoleFileName, &command, &result]() -> void {
+                result = scriptManager->evaluate(command, consoleFileName);
+            });
         }
         return result;
     });
@@ -364,7 +365,7 @@ void JSConsole::executeCommand(const QString& command) {
 }
 
 void JSConsole::commandFinished() {
-    QScriptValue result = _executeWatcher.result();
+    ScriptValue result = _executeWatcher.result();
 
     _ui->promptTextEdit->setDisabled(false);
 
@@ -373,7 +374,7 @@ void JSConsole::commandFinished() {
         _ui->promptTextEdit->setFocus();
     }
 
-    bool error = (_scriptEngine->hasUncaughtException() || result.isError());
+    bool error = (_scriptManager->engine()->hasUncaughtException() || result.isError());
     QString gutter = error ? GUTTER_ERROR : GUTTER_PREVIOUS_COMMAND;
     QString resultColor = error ? RESULT_ERROR_STYLE : RESULT_SUCCESS_STYLE;
     QString resultStr = "<span style='" + resultColor + "'>" + result.toString().toHtmlEscaped() + "</span>";
diff --git a/interface/src/ui/JSConsole.h b/interface/src/ui/JSConsole.h
index 202eb6ed6a8..4bfa4cb107d 100644
--- a/interface/src/ui/JSConsole.h
+++ b/interface/src/ui/JSConsole.h
@@ -12,13 +12,19 @@
 #ifndef hifi_JSConsole_h
 #define hifi_JSConsole_h
 
+#include <memory>
+
 #include <QFutureWatcher>
 #include <QObject>
 #include <QCompleter>
 #include <QtCore/QJsonArray>
+#include <ScriptValue.h>
 
 #include "ui_console.h"
-#include "ScriptEngine.h"
+
+class QStandardItemModel;
+class ScriptManager;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
 
 const QString CONSOLE_TITLE = "Scripting Console";
 const float CONSOLE_WINDOW_OPACITY = 0.95f;
@@ -28,10 +34,10 @@ const int CONSOLE_HEIGHT = 200;
 class JSConsole : public QWidget {
     Q_OBJECT
 public:
-    JSConsole(QWidget* parent, const ScriptEnginePointer& scriptEngine = ScriptEnginePointer());
+    JSConsole(QWidget* parent, const ScriptManagerPointer& scriptManager = ScriptManagerPointer());
     ~JSConsole();
 
-    void setScriptEngine(const ScriptEnginePointer& scriptEngine = ScriptEnginePointer());
+    void setScriptManager(const ScriptManagerPointer& scriptManager = ScriptManagerPointer());
     void clear();
 
 public slots:
@@ -66,13 +72,13 @@ private slots:
 
     QStandardItemModel* getAutoCompleteModel(const QString& memberOf = nullptr);
 
-    QFutureWatcher<QScriptValue> _executeWatcher;
+    QFutureWatcher<ScriptValue> _executeWatcher;
     Ui::Console* _ui;
     int _currentCommandInHistory;
     QString _savedHistoryFilename;
     QList<QString> _commandHistory;
     QString _rootCommand;
-    ScriptEnginePointer _scriptEngine;
+    ScriptManagerPointer _scriptManager;
     static const QString _consoleFileName;
     QJsonArray _apiDocs;
     QCompleter* _completer;
diff --git a/interface/src/ui/TestingDialog.cpp b/interface/src/ui/TestingDialog.cpp
index 5f0b20ca7e0..efaf49fc1a3 100644
--- a/interface/src/ui/TestingDialog.cpp
+++ b/interface/src/ui/TestingDialog.cpp
@@ -13,6 +13,7 @@
 
 #include "Application.h"
 #include "ScriptEngines.h"
+#include <ScriptManager.h>
 
 TestingDialog::TestingDialog(QWidget* parent) :
     QDialog(parent, Qt::Window | Qt::WindowCloseButtonHint | Qt::WindowStaysOnTopHint),
@@ -23,12 +24,12 @@ TestingDialog::TestingDialog(QWidget* parent) :
 
     _console->setFixedHeight(TESTING_CONSOLE_HEIGHT);
 
-    _engine = DependencyManager::get<ScriptEngines>()->loadScript(qApp->applicationDirPath() + testRunnerRelativePath);
-    _console->setScriptEngine(_engine);
-    connect(_engine.data(), &ScriptEngine::finished, this, &TestingDialog::onTestingFinished);
+    _scriptManager = DependencyManager::get<ScriptEngines>()->loadScript(qApp->applicationDirPath() + testRunnerRelativePath);
+    _console->setScriptManager(_scriptManager);
+    connect(_scriptManager.get(), &ScriptManager::finished, this, &TestingDialog::onTestingFinished);
 }
 
 void TestingDialog::onTestingFinished(const QString& scriptPath) {
-    _engine.reset();
-    _console->setScriptEngine();
+    _scriptManager.reset();
+    _console->setScriptManager();
 }
diff --git a/interface/src/ui/TestingDialog.h b/interface/src/ui/TestingDialog.h
index a7e909ca0e1..7707213b037 100644
--- a/interface/src/ui/TestingDialog.h
+++ b/interface/src/ui/TestingDialog.h
@@ -12,10 +12,14 @@
 #ifndef hifi_TestingDialog_h
 #define hifi_TestingDialog_h
 
+#include <memory>
+
 #include <QDialog>
-#include "ScriptEngine.h"
 #include "JSConsole.h"
 
+class ScriptManager;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
+
 const QString windowLabel = "Client Script Tests";
 const QString testRunnerRelativePath = "/scripts/developer/tests/unit_tests/testRunner.js";
 const unsigned int TESTING_CONSOLE_HEIGHT = 400;
@@ -29,7 +33,7 @@ class TestingDialog : public QDialog {
 
 private:
     std::unique_ptr<JSConsole> _console;
-    ScriptEnginePointer _engine;
+    ScriptManagerPointer _scriptManager;
 };
 
 #endif
diff --git a/interface/src/ui/overlays/Overlays.cpp b/interface/src/ui/overlays/Overlays.cpp
index d9fd9fdaa16..89a5dae0496 100644
--- a/interface/src/ui/overlays/Overlays.cpp
+++ b/interface/src/ui/overlays/Overlays.cpp
@@ -12,8 +12,6 @@
 
 #include <limits>
 
-#include <QtScript/QScriptValueIterator>
-
 #include <shared/QtHelpers.h>
 #include <OffscreenUi.h>
 #include <render/Scene.h>
@@ -30,6 +28,8 @@
 #include <PointerManager.h>
 #include <raypick/MouseTransformNode.h>
 #include <PickManager.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
 
 #include <RenderableWebEntityItem.h>
 #include "VariantMapToScriptValue.h"
@@ -42,7 +42,7 @@ Q_LOGGING_CATEGORY(trace_render_overlays, "trace.render.overlays")
 std::unordered_map<QString, QString> Overlays::_entityToOverlayTypes;
 std::unordered_map<QString, QString> Overlays::_overlayToEntityTypes;
 
-Overlays::Overlays() {
+Overlays::Overlays() : _scriptEngine(newScriptEngine()) {
     ADD_TYPE_MAP(Box, cube);
     ADD_TYPE_MAP(Sphere, sphere);
     _overlayToEntityTypes["rectangle3d"] = "Shape";
@@ -632,16 +632,16 @@ EntityItemProperties Overlays::convertOverlayToEntityProperties(QVariantMap& ove
         }
     }
 
-    QScriptEngine scriptEngine;
-    QScriptValue props = variantMapToScriptValue(overlayProps, scriptEngine);
+    ScriptEnginePointer scriptEngine = newScriptEngine();
+    ScriptValue props = variantMapToScriptValue(overlayProps, *scriptEngine);
     EntityItemProperties toReturn;
     EntityItemPropertiesFromScriptValueHonorReadOnly(props, toReturn);
     return toReturn;
 }
 
 QVariantMap Overlays::convertEntityToOverlayProperties(const EntityItemProperties& properties) {
-    QScriptEngine scriptEngine;
-    QVariantMap overlayProps = EntityItemPropertiesToScriptValue(&scriptEngine, properties).toVariant().toMap();
+    ScriptEnginePointer scriptEngine = newScriptEngine();
+    QVariantMap overlayProps = EntityItemPropertiesToScriptValue(scriptEngine.get(), properties).toVariant().toMap();
 
     QString type = overlayProps["type"].toString();
     overlayProps["type"] = entityToOverlayType(type);
@@ -740,7 +740,7 @@ QVariantMap Overlays::convertEntityToOverlayProperties(const EntityItemPropertie
         GROUP_ENTITY_TO_OVERLAY_PROP(ring, majorTickMarksColor, majorTickMarksColor);
         GROUP_ENTITY_TO_OVERLAY_PROP(ring, minorTickMarksColor, minorTickMarksColor);
     } else if (type == "PolyLine") {
-        QVector<glm::vec3> points = qVectorVec3FromScriptValue(scriptEngine.newVariant(overlayProps["linePoints"]));
+        QVector<glm::vec3> points = qVectorVec3FromScriptValue(scriptEngine->newVariant(overlayProps["linePoints"]));
         glm::vec3 position = vec3FromVariant(overlayProps["position"]);
         if (points.length() > 1) {
             overlayProps["p1"] = vec3toVariant(points[0] + position);
@@ -755,7 +755,7 @@ QVariantMap Overlays::convertEntityToOverlayProperties(const EntityItemPropertie
         RENAME_PROP(p2, endPoint);
         RENAME_PROP(p2, end);
 
-        QVector<float> widths = qVectorFloatFromScriptValue(scriptEngine.newVariant(overlayProps["strokeWidths"]));
+        QVector<float> widths = qVectorFloatFromScriptValue(scriptEngine->newVariant(overlayProps["strokeWidths"]));
         if (widths.length() > 0) {
             overlayProps["lineWidth"] = widths[0];
         }
@@ -1041,8 +1041,8 @@ QVariantMap Overlays::getOverlaysProperties(const QVariant& propertiesById) {
 }
 
 RayToOverlayIntersectionResult Overlays::findRayIntersection(const PickRay& ray, bool precisionPicking,
-                                                             const QScriptValue& overlayIDsToInclude,
-                                                             const QScriptValue& overlayIDsToDiscard,
+                                                             const ScriptValue& overlayIDsToInclude,
+                                                             const ScriptValue& overlayIDsToDiscard,
                                                              bool visibleOnly, bool collidableOnly) {
     const QVector<EntityItemID> include = qVectorEntityItemIDFromScriptValue(overlayIDsToInclude);
     const QVector<EntityItemID> discard = qVectorEntityItemIDFromScriptValue(overlayIDsToDiscard);
@@ -1110,38 +1110,39 @@ ParabolaToOverlayIntersectionResult Overlays::findParabolaIntersectionVector(con
     return overlayResult;
 }
 
-QScriptValue RayToOverlayIntersectionResultToScriptValue(QScriptEngine* engine, const RayToOverlayIntersectionResult& value) {
-    QScriptValue obj = engine->newObject();
+ScriptValue RayToOverlayIntersectionResultToScriptValue(ScriptEngine* engine, const RayToOverlayIntersectionResult& value) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("intersects", value.intersects);
-    QScriptValue overlayIDValue = quuidToScriptValue(engine, value.overlayID);
+    ScriptValue overlayIDValue = quuidToScriptValue(engine, value.overlayID);
     obj.setProperty("overlayID", overlayIDValue);
     obj.setProperty("distance", value.distance);
     obj.setProperty("face", boxFaceToString(value.face));
 
-    QScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
+    ScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
     obj.setProperty("intersection", intersection);
-    QScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
+    ScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
     obj.setProperty("surfaceNormal", surfaceNormal);
     obj.setProperty("extraInfo", engine->toScriptValue(value.extraInfo));
     return obj;
 }
 
-void RayToOverlayIntersectionResultFromScriptValue(const QScriptValue& object, RayToOverlayIntersectionResult& value) {
+bool RayToOverlayIntersectionResultFromScriptValue(const ScriptValue& object, RayToOverlayIntersectionResult& value) {
     value.intersects = object.property("intersects").toVariant().toBool();
-    QScriptValue overlayIDValue = object.property("overlayID");
+    ScriptValue overlayIDValue = object.property("overlayID");
     quuidFromScriptValue(overlayIDValue, value.overlayID);
     value.distance = object.property("distance").toVariant().toFloat();
     value.face = boxFaceFromString(object.property("face").toVariant().toString());
 
-    QScriptValue intersection = object.property("intersection");
+    ScriptValue intersection = object.property("intersection");
     if (intersection.isValid()) {
         vec3FromScriptValue(intersection, value.intersection);
     }
-    QScriptValue surfaceNormal = object.property("surfaceNormal");
+    ScriptValue surfaceNormal = object.property("surfaceNormal");
     if (surfaceNormal.isValid()) {
         vec3FromScriptValue(surfaceNormal, value.surfaceNormal);
     }
     value.extraInfo = object.property("extraInfo").toVariant().toMap();
+    return true;
 }
 
 bool Overlays::isLoaded(const QUuid& id) {
diff --git a/interface/src/ui/overlays/Overlays.h b/interface/src/ui/overlays/Overlays.h
index e59880c6d98..d13e2f821cd 100644
--- a/interface/src/ui/overlays/Overlays.h
+++ b/interface/src/ui/overlays/Overlays.h
@@ -20,15 +20,16 @@
 
 #include <QMouseEvent>
 #include <QReadWriteLock>
-#include <QScriptValue>
 
 #include <PointerEvent.h>
+#include <ScriptValue.h>
 
 #include "Overlay.h"
 
 #include <EntityScriptingInterface.h>
 
 class PickRay;
+class ScriptEngine;
 
 /*@jsdoc
  * The result of a {@link PickRay} search using {@link Overlays.findRayIntersection|findRayIntersection}.
@@ -52,8 +53,8 @@ class RayToOverlayIntersectionResult {
     QVariantMap extraInfo;
 };
 Q_DECLARE_METATYPE(RayToOverlayIntersectionResult);
-QScriptValue RayToOverlayIntersectionResultToScriptValue(QScriptEngine* engine, const RayToOverlayIntersectionResult& value);
-void RayToOverlayIntersectionResultFromScriptValue(const QScriptValue& object, RayToOverlayIntersectionResult& value);
+ScriptValue RayToOverlayIntersectionResultToScriptValue(ScriptEngine* engine, const RayToOverlayIntersectionResult& value);
+bool RayToOverlayIntersectionResultFromScriptValue(const ScriptValue& object, RayToOverlayIntersectionResult& value);
 
 class ParabolaToOverlayIntersectionResult {
 public:
@@ -120,7 +121,7 @@ class Overlays : public QObject {
 
     void cleanupAllOverlays();
 
-    mutable QScriptEngine _scriptEngine;
+    mutable ScriptEnginePointer _scriptEngine;
 
 public slots:
     /*@jsdoc
@@ -411,8 +412,8 @@ public slots:
      */
     RayToOverlayIntersectionResult findRayIntersection(const PickRay& ray,
                                                        bool precisionPicking = false,
-                                                       const QScriptValue& include = QScriptValue(),
-                                                       const QScriptValue& discard = QScriptValue(),
+                                                       const ScriptValue& include = ScriptValue(),
+                                                       const ScriptValue& discard = ScriptValue(),
                                                        bool visibleOnly = false,
                                                        bool collidableOnly = false);
 
diff --git a/libraries/animation/CMakeLists.txt b/libraries/animation/CMakeLists.txt
index 2e811969eca..d005480a313 100644
--- a/libraries/animation/CMakeLists.txt
+++ b/libraries/animation/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME animation)
-setup_hifi_library(Network Script)
-link_hifi_libraries(shared graphics model-serializers)
+setup_hifi_library(Network)
+link_hifi_libraries(shared graphics model-serializers script-engine)
 include_hifi_library_headers(networking)
 include_hifi_library_headers(gpu)
 include_hifi_library_headers(hfm)
diff --git a/libraries/animation/src/AnimVariant.cpp b/libraries/animation/src/AnimVariant.cpp
index eb9e595c88e..0b44dfd8dbc 100644
--- a/libraries/animation/src/AnimVariant.cpp
+++ b/libraries/animation/src/AnimVariant.cpp
@@ -11,20 +11,20 @@
 
 #include "AnimVariant.h" // which has AnimVariant/AnimVariantMap
 
-#include <QScriptEngine>
-#include <QScriptValueIterator>
+#include <ScriptEngine.h>
 #include <QThread>
-#include <RegisteredMetaTypes.h>
+#include <ScriptValueIterator.h>
+#include <ScriptValueUtils.h>
 
 const AnimVariant AnimVariant::False = AnimVariant();
 
-QScriptValue AnimVariantMap::animVariantMapToScriptValue(QScriptEngine* engine, const QStringList& names, bool useNames) const {
+ScriptValue AnimVariantMap::animVariantMapToScriptValue(ScriptEngine* engine, const QStringList& names, bool useNames) const {
     if (QThread::currentThread() != engine->thread()) {
         qCWarning(animation) << "Cannot create Javacript object from non-script thread" << QThread::currentThread();
         Q_ASSERT(false);
-        return QScriptValue();
+        return ScriptValue();
     }
-    QScriptValue target = engine->newObject();
+    ScriptValue target = engine->newObject();
     auto setOne = [&] (const QString& name, const AnimVariant& value) {
         switch (value.getType()) {
             case AnimVariant::Type::Bool:
@@ -74,7 +74,7 @@ void AnimVariantMap::copyVariantsFrom(const AnimVariantMap& other) {
     }
 }
 
-void AnimVariantMap::animVariantMapFromScriptValue(const QScriptValue& source) {
+void AnimVariantMap::animVariantMapFromScriptValue(const ScriptValue& source) {
     if (QThread::currentThread() != source.engine()->thread()) {
         qCWarning(animation) << "Cannot examine Javacript object from non-script thread" << QThread::currentThread();
         Q_ASSERT(false);
@@ -84,43 +84,43 @@ void AnimVariantMap::animVariantMapFromScriptValue(const QScriptValue& source) {
     // Whenever we identify a new outbound type in animVariantMapToScriptValue above, or a new inbound type in the code that follows here,
     // we would enter it into the dictionary. Then switch on that type here, with the code that follow being executed only if
     // the type is not known. One problem with that is that there is no checking that two different script use the same name differently.
-    QScriptValueIterator property(source);
-    // Note: QScriptValueIterator iterates only over source's own properties. It does not follow the prototype chain.
-    while (property.hasNext()) {
-        property.next();
-        QScriptValue value = property.value();
+    ScriptValueIteratorPointer property(source.newIterator());
+    // Note: ScriptValueIterator iterates only over source's own properties. It does not follow the prototype chain.
+    while (property->hasNext()) {
+        property->next();
+        ScriptValue value = property->value();
         if (value.isBool()) {
-            set(property.name(), value.toBool());
+            set(property->name(), value.toBool());
         } else if (value.isString()) {
-            set(property.name(), value.toString());
+            set(property->name(), value.toString());
         } else if (value.isNumber()) {
             int asInteger = value.toInt32();
             float asFloat = value.toNumber();
             if (asInteger == asFloat) {
-                set(property.name(), asInteger);
+                set(property->name(), asInteger);
             } else {
-                set(property.name(), asFloat);
+                set(property->name(), asFloat);
             }
         } else { // Try to get x,y,z and possibly w
             if (value.isObject()) {
-                QScriptValue x = value.property("x");
+                ScriptValue x = value.property("x");
                 if (x.isNumber()) {
-                    QScriptValue y = value.property("y");
+                    ScriptValue y = value.property("y");
                     if (y.isNumber()) {
-                        QScriptValue z = value.property("z");
+                        ScriptValue z = value.property("z");
                         if (z.isNumber()) {
-                            QScriptValue w = value.property("w");
+                            ScriptValue w = value.property("w");
                             if (w.isNumber()) {
-                                set(property.name(), glm::quat(w.toNumber(), x.toNumber(), y.toNumber(), z.toNumber()));
+                                set(property->name(), glm::quat(w.toNumber(), x.toNumber(), y.toNumber(), z.toNumber()));
                             } else {
-                                set(property.name(), glm::vec3(x.toNumber(), y.toNumber(), z.toNumber()));
+                                set(property->name(), glm::vec3(x.toNumber(), y.toNumber(), z.toNumber()));
                             }
                             continue; // we got either a vector or quaternion object, so don't fall through to warning
                         }
                     }
                 }
             }
-            qCWarning(animation) << "Ignoring unrecognized data" << value.toString() << "for animation property" << property.name();
+            qCWarning(animation) << "Ignoring unrecognized data " << value.toString() << " for animation property " << property->name();
             Q_ASSERT(false);
         }
     }
diff --git a/libraries/animation/src/AnimVariant.h b/libraries/animation/src/AnimVariant.h
index a8bdb885e54..83cebaa7af1 100644
--- a/libraries/animation/src/AnimVariant.h
+++ b/libraries/animation/src/AnimVariant.h
@@ -17,10 +17,12 @@
 #include <glm/gtx/quaternion.hpp>
 #include <map>
 #include <set>
-#include <QScriptValue>
 #include <StreamUtils.h>
 #include <GLMHelpers.h>
 #include "AnimationLogging.h"
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class AnimVariant {
 public:
@@ -229,9 +231,9 @@ class AnimVariantMap {
     }
 
     // Answer a Plain Old Javascript Object (for the given engine) all of our values set as properties.
-    QScriptValue animVariantMapToScriptValue(QScriptEngine* engine, const QStringList& names, bool useNames) const;
+    ScriptValue animVariantMapToScriptValue(ScriptEngine* engine, const QStringList& names, bool useNames) const;
     // Side-effect us with the value of object's own properties. (No inherited properties.)
-    void animVariantMapFromScriptValue(const QScriptValue& object);
+    void animVariantMapFromScriptValue(const ScriptValue& object);
     void copyVariantsFrom(const AnimVariantMap& other);
 
     // For stat debugging.
@@ -274,7 +276,7 @@ class AnimVariantMap {
     glm::quat _rigToGeometryRot;
 };
 
-typedef std::function<void(QScriptValue)> AnimVariantResultHandler;
+typedef std::function<void(ScriptValue)> AnimVariantResultHandler;
 Q_DECLARE_METATYPE(AnimVariantResultHandler);
 Q_DECLARE_METATYPE(AnimVariantMap)
 
diff --git a/libraries/animation/src/AnimationCache.h b/libraries/animation/src/AnimationCache.h
index b1f0cc13a2f..95611cb646e 100644
--- a/libraries/animation/src/AnimationCache.h
+++ b/libraries/animation/src/AnimationCache.h
@@ -14,8 +14,6 @@
 
 #include <QtCore/QRunnable>
 #include <QtCore/QSharedPointer>
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValue>
 
 #include <DependencyManager.h>
 #include <hfm/HFM.h>
diff --git a/libraries/animation/src/AnimationObject.cpp b/libraries/animation/src/AnimationObject.cpp
index bcbf4971995..6782768f5b4 100644
--- a/libraries/animation/src/AnimationObject.cpp
+++ b/libraries/animation/src/AnimationObject.cpp
@@ -11,27 +11,34 @@
 
 #include "AnimationObject.h"
 
-#include <QScriptEngine>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
 #include "AnimationCache.h"
 
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    registerAnimationTypes(manager->engine().get());
+});
+
 QStringList AnimationObject::getJointNames() const {
-    return qscriptvalue_cast<AnimationPointer>(thisObject())->getJointNames();
+    return scriptvalue_cast<AnimationPointer>(thisObject())->getJointNames();
 }
 
 QVector<HFMAnimationFrame> AnimationObject::getFrames() const {
-    return qscriptvalue_cast<AnimationPointer>(thisObject())->getFrames();
+    return scriptvalue_cast<AnimationPointer>(thisObject())->getFrames();
 }
 
 QVector<glm::quat> AnimationFrameObject::getRotations() const {
-    return qscriptvalue_cast<HFMAnimationFrame>(thisObject()).rotations;
+    return scriptvalue_cast<HFMAnimationFrame>(thisObject()).rotations;
 }
 
-void registerAnimationTypes(QScriptEngine* engine) {
-    qScriptRegisterSequenceMetaType<QVector<HFMAnimationFrame> >(engine);
+void registerAnimationTypes(ScriptEngine* engine) {
+    scriptRegisterSequenceMetaType<QVector<HFMAnimationFrame> >(engine);
     engine->setDefaultPrototype(qMetaTypeId<HFMAnimationFrame>(), engine->newQObject(
-        new AnimationFrameObject(), QScriptEngine::ScriptOwnership));
+        new AnimationFrameObject(), ScriptEngine::ScriptOwnership));
     engine->setDefaultPrototype(qMetaTypeId<AnimationPointer>(), engine->newQObject(
-        new AnimationObject(), QScriptEngine::ScriptOwnership));
+        new AnimationObject(), ScriptEngine::ScriptOwnership));
 }
 
diff --git a/libraries/animation/src/AnimationObject.h b/libraries/animation/src/AnimationObject.h
index 466deb5e963..d170b15b082 100644
--- a/libraries/animation/src/AnimationObject.h
+++ b/libraries/animation/src/AnimationObject.h
@@ -13,11 +13,11 @@
 #define hifi_AnimationObject_h
 
 #include <QObject>
-#include <QScriptable>
 
 #include <FBXSerializer.h>
+#include "Scriptable.h"
 
-class QScriptEngine;
+class ScriptEngine;
 
 /*@jsdoc
  * Information about an animation resource, created by {@link AnimationCache.getAnimation}.
@@ -35,7 +35,7 @@ class QScriptEngine;
  * @property {AnimationFrameObject[]} frames - The frames in the animation. <em>Read-only.</em>
  */
 /// Scriptable wrapper for animation pointers.
-class AnimationObject : public QObject, protected QScriptable {
+class AnimationObject : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(QStringList jointNames READ getJointNames)
     Q_PROPERTY(QVector<HFMAnimationFrame> frames READ getFrames)
@@ -72,7 +72,7 @@ class AnimationObject : public QObject, protected QScriptable {
  * @property {Quat[]} rotations - Joint rotations. <em>Read-only.</em>
  */
 /// Scriptable wrapper for animation frames.
-class AnimationFrameObject : public QObject, protected QScriptable {
+class AnimationFrameObject : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(QVector<glm::quat> rotations READ getRotations)
 
@@ -86,6 +86,6 @@ class AnimationFrameObject : public QObject, protected QScriptable {
     Q_INVOKABLE QVector<glm::quat> getRotations() const;
 };
 
-void registerAnimationTypes(QScriptEngine* engine);
+void registerAnimationTypes(ScriptEngine* engine);
 
 #endif // hifi_AnimationObject_h
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index ba042d31a88..46dff832c9c 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -13,7 +13,6 @@
 
 #include <glm/gtx/vector_angle.hpp>
 #include <queue>
-#include <QScriptValueIterator>
 #include <QWriteLocker>
 #include <QReadLocker>
 
@@ -21,7 +20,10 @@
 #include <NumericalConstants.h>
 #include <DebugDraw.h>
 #include <PerfStat.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
 #include <ScriptValueUtils.h>
+#include <ScriptValue.h>
 #include <shared/NsightHelpers.h>
 
 #include "AnimationLogging.h"
@@ -1584,7 +1586,7 @@ void Rig::computeMotionAnimationState(float deltaTime, const glm::vec3& worldPos
 }
 
 // Allow script to add/remove handlers and report results, from within their thread.
-QScriptValue Rig::addAnimationStateHandler(QScriptValue handler, QScriptValue propertiesList) { // called in script thread
+ScriptValue Rig::addAnimationStateHandler(const ScriptValue& handler, const ScriptValue& propertiesList) { // called in script thread
 
     // validate argument types
     if (handler.isFunction() && (isListOfStrings(propertiesList) || propertiesList.isUndefined() || propertiesList.isNull())) {
@@ -1599,14 +1601,14 @@ QScriptValue Rig::addAnimationStateHandler(QScriptValue handler, QScriptValue pr
         if (data.useNames) {
             data.propertyNames = propertiesList.toVariant().toStringList();
         }
-        return QScriptValue(_nextStateHandlerId); // suitable for giving to removeAnimationStateHandler
+        return handler.engine()->newValue(_nextStateHandlerId);  // suitable for giving to removeAnimationStateHandler
     } else {
         qCWarning(animation) << "Rig::addAnimationStateHandler invalid arguments, expected (function, string[])";
-        return QScriptValue(QScriptValue::UndefinedValue);
+        return handler.engine() ? handler.engine()->undefinedValue() : ScriptValue();
     }
 }
 
-void Rig::removeAnimationStateHandler(QScriptValue identifier) { // called in script thread
+void Rig::removeAnimationStateHandler(const ScriptValue& identifier) {  // called in script thread
     // validate arguments
     if (identifier.isNumber()) {
         QMutexLocker locker(&_stateMutex);
@@ -1616,7 +1618,7 @@ void Rig::removeAnimationStateHandler(QScriptValue identifier) { // called in sc
     }
 }
 
-void Rig::animationStateHandlerResult(int identifier, QScriptValue result) { // called synchronously from script
+void Rig::animationStateHandlerResult(int identifier, const ScriptValue& result) {  // called synchronously from script
     QMutexLocker locker(&_stateMutex);
     auto found = _stateHandlers.find(identifier);
     if (found == _stateHandlers.end()) {
@@ -1635,9 +1637,9 @@ void Rig::updateAnimationStateHandlers() { // called on avatar update thread (wh
         // call out:
         int identifier = data.key();
         StateHandler& value = data.value();
-        QScriptValue& function = value.function;
+        ScriptValue& function = value.function;
         int rigId = _rigId;
-        auto handleResult = [rigId, identifier](QScriptValue result) { // called in script thread to get the result back to us.
+        auto handleResult = [rigId, identifier](const ScriptValue& result) { // called in script thread to get the result back to us.
             // Hold the rigRegistryMutex to ensure thread-safe access to the rigRegistry, but
             // also to prevent the rig from being deleted while this lambda is being executed.
             std::lock_guard<std::mutex> guard(rigRegistryMutex);
@@ -1650,14 +1652,35 @@ void Rig::updateAnimationStateHandlers() { // called on avatar update thread (wh
                 rig->animationStateHandlerResult(identifier, result);
             }
         };
-        // invokeMethod makes a copy of the args, and copies of AnimVariantMap do copy the underlying map, so this will correctly capture
-        // the state of _animVars and allow continued changes to _animVars in this thread without conflict.
-        QMetaObject::invokeMethod(function.engine(), "callAnimationStateHandler",  Qt::QueuedConnection,
-                                  Q_ARG(QScriptValue, function),
-                                  Q_ARG(AnimVariantMap, _animVars),
-                                  Q_ARG(QStringList, value.propertyNames),
-                                  Q_ARG(bool, value.useNames),
-                                  Q_ARG(AnimVariantResultHandler, handleResult));
+
+        {
+            // make references to the parameters for the lambda here, but let the lambda be the one to take the copies
+            // Copies of AnimVariantMap do copy the underlying map, so this will correctly capture
+            // the state of _animVars and allow continued changes to _animVars in this thread without conflict.
+            const AnimVariantMap& animVars = _animVars;
+            ScriptEnginePointer engine = function.engine();
+            const QStringList& names = value.propertyNames;
+            bool useNames = value.useNames;
+
+            QMetaObject::invokeMethod(
+                engine->manager(),
+                [function, animVars, names, useNames, handleResult, engine] {
+                    ScriptValue javascriptParameters = animVars.animVariantMapToScriptValue(engine.get(), names, useNames);
+                    ScriptValueList callingArguments;
+                    callingArguments << javascriptParameters;
+                    ScriptValue result = function.call(ScriptValue(), callingArguments);
+
+                    // validate result from callback function.
+                    if (result.isValid() && result.isObject()) {
+                        handleResult(result);
+                    } else {
+                        qCWarning(animation) << "Rig::updateAnimationStateHandlers invalid return argument from "
+                                                "callback, expected an object";
+                    }
+                },
+                Qt::QueuedConnection);
+        }
+
         // It turns out that, for thread-safety reasons, ScriptEngine::callAnimationStateHandler will invoke itself if called from other
         // than the script thread. Thus the above _could_ be replaced with an ordinary call, which will then trigger the same
         // invokeMethod as is done explicitly above. However, the script-engine library depends on this animation library, not vice versa.
diff --git a/libraries/animation/src/Rig.h b/libraries/animation/src/Rig.h
index c58be799cfe..9b7704bc159 100644
--- a/libraries/animation/src/Rig.h
+++ b/libraries/animation/src/Rig.h
@@ -16,10 +16,10 @@
 
 #include <QObject>
 #include <QMutex>
-#include <QScriptValue>
 #include <vector>
 #include <JointData.h>
 #include <QReadWriteLock>
+#include <ScriptValue.h>
 
 #include "AnimNode.h"
 #include "AnimNodeLoader.h"
@@ -40,7 +40,7 @@ class Rig : public QObject {
     struct StateHandler {
         AnimVariantMap results;
         QStringList propertyNames;
-        QScriptValue function;
+        ScriptValue function;
         bool useNames;
     };
 
@@ -205,9 +205,9 @@ class Rig : public QObject {
     AnimNode::ConstPointer getAnimNode() const { return _animNode; }
     AnimNode::ConstPointer findAnimNodeByName(const QString& name) const;
     AnimSkeleton::ConstPointer getAnimSkeleton() const { return _animSkeleton; }
-    QScriptValue addAnimationStateHandler(QScriptValue handler, QScriptValue propertiesList);
-    void removeAnimationStateHandler(QScriptValue handler);
-    void animationStateHandlerResult(int identifier, QScriptValue result);
+    ScriptValue addAnimationStateHandler(const ScriptValue& handler, const ScriptValue& propertiesList);
+    void removeAnimationStateHandler(const ScriptValue& handler);
+    void animationStateHandlerResult(int identifier, const ScriptValue& result);
 
     // rig space
     bool getModelRegistrationPoint(glm::vec3& modelRegistrationPointOut) const;
diff --git a/libraries/audio-client/CMakeLists.txt b/libraries/audio-client/CMakeLists.txt
index 6b88292dd4e..03a9fc087ba 100644
--- a/libraries/audio-client/CMakeLists.txt
+++ b/libraries/audio-client/CMakeLists.txt
@@ -6,6 +6,7 @@ setup_hifi_library(Network Multimedia ${PLATFORM_QT_COMPONENTS})
 link_hifi_libraries(audio plugins)
 include_hifi_library_headers(shared)
 include_hifi_library_headers(networking)
+include_hifi_library_headers(script-engine)
 
 if (ANDROID)
 else ()
diff --git a/libraries/audio/CMakeLists.txt b/libraries/audio/CMakeLists.txt
index a8a398c14ff..7260e21259d 100644
--- a/libraries/audio/CMakeLists.txt
+++ b/libraries/audio/CMakeLists.txt
@@ -5,4 +5,4 @@ if (ANDROID)
   add_definitions("-D__STDC_CONSTANT_MACROS")
 endif ()
 
-link_hifi_libraries(networking shared plugins)
+link_hifi_libraries(networking shared plugins script-engine)
diff --git a/libraries/audio/src/AudioEffectOptions.cpp b/libraries/audio/src/AudioEffectOptions.cpp
index 186689d2b46..bed083d7dbd 100644
--- a/libraries/audio/src/AudioEffectOptions.cpp
+++ b/libraries/audio/src/AudioEffectOptions.cpp
@@ -10,6 +10,18 @@
 
 #include "AudioEffectOptions.h"
 
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
+
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine();
+
+    ScriptValue audioEffectOptionsConstructorValue = scriptEngine->newFunction(AudioEffectOptions::constructor);
+    scriptEngine->globalObject().setProperty("AudioEffectOptions", audioEffectOptionsConstructorValue);
+});
+
 static const QString BANDWIDTH_HANDLE = "bandwidth";
 static const QString PRE_DELAY_HANDLE = "preDelay";
 static const QString LATE_DELAY_HANDLE = "lateDelay";
@@ -54,7 +66,7 @@ static const float LATE_MIX_LEFT_DEFAULT = 90.0f;
 static const float LATE_MIX_RIGHT_DEFAULT = 90.0f;
 static const float WET_DRY_MIX_DEFAULT = 50.0f;
 
-static void setOption(QScriptValue arguments, const QString name, float defaultValue, float& variable) {
+static void setOption(const ScriptValue& arguments, const QString name, float defaultValue, float& variable) {
     variable = arguments.property(name).isNumber() ? (float)arguments.property(name).toNumber() : defaultValue;
 }
 
@@ -83,7 +95,7 @@ static void setOption(QScriptValue arguments, const QString name, float defaultV
  * @property {number} lateMixRight=90 - The apparent distance of the source (percent) in the reverb tail.
  * @property {number} wetDryMix=50 - Adjusts the wet/dry ratio, from completely dry (0%) to completely wet (100%).
  */
-AudioEffectOptions::AudioEffectOptions(QScriptValue arguments) {
+AudioEffectOptions::AudioEffectOptions(const ScriptValue& arguments) {
     setOption(arguments, BANDWIDTH_HANDLE, BANDWIDTH_DEFAULT, _bandwidth);
     setOption(arguments, PRE_DELAY_HANDLE, PRE_DELAY_DEFAULT, _preDelay);
     setOption(arguments, LATE_DELAY_HANDLE, LATE_DELAY_DEFAULT, _lateDelay);
@@ -137,6 +149,6 @@ AudioEffectOptions& AudioEffectOptions::operator=(const AudioEffectOptions &othe
     return *this;
 }
 
-QScriptValue AudioEffectOptions::constructor(QScriptContext* context, QScriptEngine* engine) {
-    return engine->newQObject(new AudioEffectOptions(context->argument(0)));
+ScriptValue AudioEffectOptions::constructor(ScriptContext* context, ScriptEngine* engine) {
+    return engine->newQObject(new AudioEffectOptions(context->argument(0)), ScriptEngine::ScriptOwnership);
 }
diff --git a/libraries/audio/src/AudioEffectOptions.h b/libraries/audio/src/AudioEffectOptions.h
index 14b39e0f33c..7ac2c83a248 100644
--- a/libraries/audio/src/AudioEffectOptions.h
+++ b/libraries/audio/src/AudioEffectOptions.h
@@ -12,8 +12,10 @@
 #define hifi_AudioEffectOptions_h
 
 #include <QObject>
-#include <QtScript/QScriptContext>
-#include <QtScript/QScriptEngine>
+#include <ScriptValue.h>
+
+class ScriptContext;
+class ScriptEngine;
 
 /*@jsdoc
  * Audio effect options used by the {@link Audio} API.
@@ -78,11 +80,11 @@ class AudioEffectOptions : public QObject {
     Q_PROPERTY(float wetDryMix READ getWetDryMix WRITE setWetDryMix)
 
 public:
-    AudioEffectOptions(QScriptValue arguments = QScriptValue());
+    AudioEffectOptions(const ScriptValue& arguments = ScriptValue());
     AudioEffectOptions(const AudioEffectOptions &other);
     AudioEffectOptions& operator=(const AudioEffectOptions &other);
 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine);
 
     float getBandwidth() const { return _bandwidth; }
     void setBandwidth(float bandwidth) { _bandwidth = bandwidth; }
diff --git a/libraries/audio/src/AudioInjectorOptions.cpp b/libraries/audio/src/AudioInjectorOptions.cpp
index 39b807fd769..804d935a46d 100644
--- a/libraries/audio/src/AudioInjectorOptions.cpp
+++ b/libraries/audio/src/AudioInjectorOptions.cpp
@@ -11,9 +11,9 @@
 
 #include "AudioInjectorOptions.h"
 
-#include <QScriptValueIterator>
-
-#include <RegisteredMetaTypes.h>
+#include <ScriptValueIterator.h>
+#include <ScriptValueUtils.h>
+#include <ScriptEngine.h>
 
 #include "AudioLogging.h"
 
@@ -32,8 +32,8 @@ AudioInjectorOptions::AudioInjectorOptions() :
 {
 }
 
-QScriptValue injectorOptionsToScriptValue(QScriptEngine* engine, const AudioInjectorOptions& injectorOptions) {
-    QScriptValue obj = engine->newObject();
+ScriptValue injectorOptionsToScriptValue(ScriptEngine* engine, const AudioInjectorOptions& injectorOptions) {
+    ScriptValue obj = engine->newObject();
     if (injectorOptions.positionSet) {
         obj.setProperty("position", vec3ToScriptValue(engine, injectorOptions.position));
     }
@@ -66,10 +66,10 @@ QScriptValue injectorOptionsToScriptValue(QScriptEngine* engine, const AudioInje
  * @property {boolean} ignorePenumbra=false - <p class="important">Deprecated: This property is deprecated and will be
  *     removed.</p>
  */
-void injectorOptionsFromScriptValue(const QScriptValue& object, AudioInjectorOptions& injectorOptions) {
+bool injectorOptionsFromScriptValue(const ScriptValue& object, AudioInjectorOptions& injectorOptions) {
     if (!object.isObject()) {
         qWarning() << "Audio injector options is not an object.";
-        return;
+        return false;
     }
 
     if (injectorOptions.positionSet == false) {
@@ -77,53 +77,54 @@ void injectorOptionsFromScriptValue(const QScriptValue& object, AudioInjectorOpt
     }
     injectorOptions.positionSet = false;
 
-    QScriptValueIterator it(object);
-    while (it.hasNext()) {
-        it.next();
+    ScriptValueIteratorPointer it(object.newIterator());
+    while (it->hasNext()) {
+        it->next();
 
-        if (it.name() == "position") {
+        if (it->name() == "position") {
             vec3FromScriptValue(object.property("position"), injectorOptions.position);
             injectorOptions.positionSet = true;
-        } else if (it.name() == "orientation") {
+        } else if (it->name() == "orientation") {
             quatFromScriptValue(object.property("orientation"), injectorOptions.orientation);
-        } else if (it.name() == "volume") {
-            if (it.value().isNumber()) {
-                injectorOptions.volume = it.value().toNumber();
+        } else if (it->name() == "volume") {
+            if (it->value().isNumber()) {
+                injectorOptions.volume = it->value().toNumber();
             } else {
                 qCWarning(audio) << "Audio injector options: volume is not a number";
             }
-        } else if (it.name() == "loop") {
-            if (it.value().isBool()) {
-                injectorOptions.loop = it.value().toBool();
+        } else if (it->name() == "loop") {
+            if (it->value().isBool()) {
+                injectorOptions.loop = it->value().toBool();
             } else {
                 qCWarning(audio) << "Audio injector options: loop is not a boolean";
             }
-        } else if (it.name() == "ignorePenumbra") {
-            if (it.value().isBool()) {
-                injectorOptions.ignorePenumbra = it.value().toBool();
+        } else if (it->name() == "ignorePenumbra") {
+            if (it->value().isBool()) {
+                injectorOptions.ignorePenumbra = it->value().toBool();
             } else {
                 qCWarning(audio) << "Audio injector options: ignorePenumbra is not a boolean";
             }
-        } else if (it.name() == "localOnly") {
-            if (it.value().isBool()) {
-                injectorOptions.localOnly = it.value().toBool();
+        } else if (it->name() == "localOnly") {
+            if (it->value().isBool()) {
+                injectorOptions.localOnly = it->value().toBool();
             } else {
                 qCWarning(audio) << "Audio injector options: localOnly is not a boolean";
             }
-        } else if (it.name() == "secondOffset") {
-            if (it.value().isNumber()) {
-                injectorOptions.secondOffset = it.value().toNumber();
+        } else if (it->name() == "secondOffset") {
+            if (it->value().isNumber()) {
+                injectorOptions.secondOffset = it->value().toNumber();
             } else {
                 qCWarning(audio) << "Audio injector options: secondOffset is not a number";
             }
-        } else if (it.name() == "pitch") {
-            if (it.value().isNumber()) {
-                injectorOptions.pitch = it.value().toNumber();
+        } else if (it->name() == "pitch") {
+            if (it->value().isNumber()) {
+                injectorOptions.pitch = it->value().toNumber();
             } else {
                 qCWarning(audio) << "Audio injector options: pitch is not a number";
             }
         } else {
-            qCWarning(audio) << "Unknown audio injector option:" << it.name();
+            qCWarning(audio) << "Unknown audio injector option:" << it->name();
         }
     }
+    return true;
 }
diff --git a/libraries/audio/src/AudioInjectorOptions.h b/libraries/audio/src/AudioInjectorOptions.h
index 5dec8a02403..fda05f01177 100644
--- a/libraries/audio/src/AudioInjectorOptions.h
+++ b/libraries/audio/src/AudioInjectorOptions.h
@@ -12,10 +12,11 @@
 #ifndef hifi_AudioInjectorOptions_h
 #define hifi_AudioInjectorOptions_h
 
-#include <QtScript/qscriptengine.h>
-
 #include <glm/glm.hpp>
 #include <glm/gtx/quaternion.hpp>
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class AudioInjectorOptions {
 public:
@@ -35,7 +36,7 @@ class AudioInjectorOptions {
 
 Q_DECLARE_METATYPE(AudioInjectorOptions);
 
-QScriptValue injectorOptionsToScriptValue(QScriptEngine* engine, const AudioInjectorOptions& injectorOptions);
-void injectorOptionsFromScriptValue(const QScriptValue& object, AudioInjectorOptions& injectorOptions);
+ScriptValue injectorOptionsToScriptValue(ScriptEngine* engine, const AudioInjectorOptions& injectorOptions);
+bool injectorOptionsFromScriptValue(const ScriptValue& object, AudioInjectorOptions& injectorOptions);
 
 #endif // hifi_AudioInjectorOptions_h
diff --git a/libraries/script-engine/src/AudioScriptingInterface.cpp b/libraries/audio/src/AudioScriptingInterface.cpp
similarity index 85%
rename from libraries/script-engine/src/AudioScriptingInterface.cpp
rename to libraries/audio/src/AudioScriptingInterface.cpp
index a55cac292f8..ec7a50e5df1 100644
--- a/libraries/script-engine/src/AudioScriptingInterface.cpp
+++ b/libraries/audio/src/AudioScriptingInterface.cpp
@@ -16,11 +16,23 @@
 #include <shared/QtHelpers.h>
 
 #include "ScriptAudioInjector.h"
-#include "ScriptEngineLogging.h"
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptEngineLogging.h>
+#include <ScriptManager.h>
 
-void registerAudioMetaTypes(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, injectorOptionsToScriptValue, injectorOptionsFromScriptValue);
-    qScriptRegisterMetaType(engine, soundSharedPointerToScriptValue, soundSharedPointerFromScriptValue);
+
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager){
+    auto scriptEngine = manager->engine().get();
+
+    registerAudioMetaTypes(scriptEngine);
+    scriptEngine->registerGlobalObject("Audio", DependencyManager::get<AudioScriptingInterface>().data());
+});
+
+
+void registerAudioMetaTypes(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, injectorOptionsToScriptValue, injectorOptionsFromScriptValue);
+    scriptRegisterMetaType(engine, soundSharedPointerToScriptValue, soundSharedPointerFromScriptValue);
 }
 
 
diff --git a/libraries/script-engine/src/AudioScriptingInterface.h b/libraries/audio/src/AudioScriptingInterface.h
similarity index 98%
rename from libraries/script-engine/src/AudioScriptingInterface.h
rename to libraries/audio/src/AudioScriptingInterface.h
index 6bfb7352ee8..0c0e3144fa5 100644
--- a/libraries/script-engine/src/AudioScriptingInterface.h
+++ b/libraries/audio/src/AudioScriptingInterface.h
@@ -15,12 +15,13 @@
 #ifndef hifi_AudioScriptingInterface_h
 #define hifi_AudioScriptingInterface_h
 
-#include <AbstractAudioInterface.h>
-#include <AudioInjector.h>
+#include "AbstractAudioInterface.h"
+#include "AudioInjector.h"
 #include <DependencyManager.h>
-#include <Sound.h>
+#include "Sound.h"
 
 class ScriptAudioInjector;
+class ScriptEngine;
 
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Audio.html">Audio</a></code> scripting API
 class AudioScriptingInterface : public QObject, public Dependency {
@@ -291,7 +292,7 @@ class AudioScriptingInterface : public QObject, public Dependency {
     AbstractAudioInterface* _localAudioInterface { nullptr };
 };
 
-void registerAudioMetaTypes(QScriptEngine* engine);
+void registerAudioMetaTypes(ScriptEngine* engine);
 
 #endif // hifi_AudioScriptingInterface_h
 
diff --git a/libraries/script-engine/src/ScriptAudioInjector.cpp b/libraries/audio/src/ScriptAudioInjector.cpp
similarity index 62%
rename from libraries/script-engine/src/ScriptAudioInjector.cpp
rename to libraries/audio/src/ScriptAudioInjector.cpp
index 0e42ec31e70..28af8b849aa 100644
--- a/libraries/script-engine/src/ScriptAudioInjector.cpp
+++ b/libraries/audio/src/ScriptAudioInjector.cpp
@@ -1,6 +1,6 @@
 //
 //  ScriptAudioInjector.cpp
-//  libraries/script-engine/src
+//  libraries/audio/src
 //
 //  Created by Stephen Birarda on 2015-02-11.
 //  Copyright 2015 High Fidelity, Inc.
@@ -11,19 +11,30 @@
 
 #include "ScriptAudioInjector.h"
 
-#include "ScriptEngineLogging.h"
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptEngineLogging.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
-QScriptValue injectorToScriptValue(QScriptEngine* engine, ScriptAudioInjector* const& in) {
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine().get();
+
+    scriptRegisterMetaType(scriptEngine, injectorToScriptValue, injectorFromScriptValue);
+});
+
+ScriptValue injectorToScriptValue(ScriptEngine* engine, ScriptAudioInjector* const& in) {
     // The AudioScriptingInterface::playSound method can return null, so we need to account for that.
     if (!in) {
-        return QScriptValue(QScriptValue::NullValue);
+        return engine->nullValue();
     }
 
-    return engine->newQObject(in, QScriptEngine::ScriptOwnership);
+    return engine->newQObject(in, ScriptEngine::ScriptOwnership);
 }
 
-void injectorFromScriptValue(const QScriptValue& object, ScriptAudioInjector*& out) {
+bool injectorFromScriptValue(const ScriptValue& object, ScriptAudioInjector*& out) {
     out = qobject_cast<ScriptAudioInjector*>(object.toQObject());
+    return true;
 }
 
 ScriptAudioInjector::ScriptAudioInjector(const AudioInjectorPointer& injector) :
diff --git a/libraries/script-engine/src/ScriptAudioInjector.h b/libraries/audio/src/ScriptAudioInjector.h
similarity index 93%
rename from libraries/script-engine/src/ScriptAudioInjector.h
rename to libraries/audio/src/ScriptAudioInjector.h
index 8818ffab43b..18d0ba72a48 100644
--- a/libraries/script-engine/src/ScriptAudioInjector.h
+++ b/libraries/audio/src/ScriptAudioInjector.h
@@ -1,6 +1,6 @@
 //
 //  ScriptAudioInjector.h
-//  libraries/script-engine/src
+//  libraries/audio/src
 //
 //  Created by Stephen Birarda on 2015-02-11.
 //  Copyright 2015 High Fidelity, Inc.
@@ -16,8 +16,11 @@
 #define hifi_ScriptAudioInjector_h
 
 #include <QtCore/QObject>
+#include <ScriptValue.h>
 
-#include <AudioInjectorManager.h>
+#include "AudioInjectorManager.h"
+
+class ScriptEngine;
 
 /*@jsdoc
  * Plays or "injects" the content of an audio file.
@@ -143,13 +146,13 @@ public slots:
 private:
     QWeakPointer<AudioInjector> _injector;
 
-    friend QScriptValue injectorToScriptValue(QScriptEngine* engine, ScriptAudioInjector* const& in);
+    friend ScriptValue injectorToScriptValue(ScriptEngine* engine, ScriptAudioInjector* const& in);
 };
 
 Q_DECLARE_METATYPE(ScriptAudioInjector*)
 
-QScriptValue injectorToScriptValue(QScriptEngine* engine, ScriptAudioInjector* const& in);
-void injectorFromScriptValue(const QScriptValue& object, ScriptAudioInjector*& out);
+ScriptValue injectorToScriptValue(ScriptEngine* engine, ScriptAudioInjector* const& in);
+bool injectorFromScriptValue(const ScriptValue& object, ScriptAudioInjector*& out);
 
 #endif // hifi_ScriptAudioInjector_h
 
diff --git a/libraries/audio/src/Sound.cpp b/libraries/audio/src/Sound.cpp
index 7c5dd3813bc..e0f70cc121a 100644
--- a/libraries/audio/src/Sound.cpp
+++ b/libraries/audio/src/Sound.cpp
@@ -26,6 +26,8 @@
 #include <LimitedNodeList.h>
 #include <NetworkAccessManager.h>
 #include <SharedUtil.h>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 
 #include "AudioRingBuffer.h"
 #include "AudioLogging.h"
@@ -422,14 +424,15 @@ SoundProcessor::AudioProperties SoundProcessor::interpretAsMP3(const QByteArray&
 }
 
 
-QScriptValue soundSharedPointerToScriptValue(QScriptEngine* engine, const SharedSoundPointer& in) {
-    return engine->newQObject(new SoundScriptingInterface(in), QScriptEngine::ScriptOwnership);
+ScriptValue soundSharedPointerToScriptValue(ScriptEngine* engine, const SharedSoundPointer& in) {
+    return engine->newQObject(new SoundScriptingInterface(in), ScriptEngine::ScriptOwnership);
 }
 
-void soundSharedPointerFromScriptValue(const QScriptValue& object, SharedSoundPointer& out) {
+bool soundSharedPointerFromScriptValue(const ScriptValue& object, SharedSoundPointer& out) {
     if (auto soundInterface = qobject_cast<SoundScriptingInterface*>(object.toQObject())) {
         out = soundInterface->getSound();
     }
+    return true;
 }
 
 SoundScriptingInterface::SoundScriptingInterface(const SharedSoundPointer& sound) : _sound(sound) {
diff --git a/libraries/audio/src/Sound.h b/libraries/audio/src/Sound.h
index eb6bc67c669..f38d2991ce1 100644
--- a/libraries/audio/src/Sound.h
+++ b/libraries/audio/src/Sound.h
@@ -16,13 +16,15 @@
 #include <QtCore/QObject>
 #include <QtCore/QSharedPointer>
 #include <QtNetwork/QNetworkReply>
-#include <QtScript/qscriptengine.h>
+#include <QtCore/QSharedPointer>
 
 #include <ResourceCache.h>
+#include <ScriptValue.h>
 
 #include "AudioConstants.h"
 
 class AudioData;
+class ScriptEngine;
 using AudioDataPointer = std::shared_ptr<const AudioData>;
 
 Q_DECLARE_METATYPE(AudioDataPointer);
@@ -169,7 +171,7 @@ class SoundScriptingInterface : public QObject {
 };
 
 Q_DECLARE_METATYPE(SharedSoundPointer)
-QScriptValue soundSharedPointerToScriptValue(QScriptEngine* engine, const SharedSoundPointer& in);
-void soundSharedPointerFromScriptValue(const QScriptValue& object, SharedSoundPointer& out);
+ScriptValue soundSharedPointerToScriptValue(ScriptEngine* engine, const SharedSoundPointer& in);
+bool soundSharedPointerFromScriptValue(const ScriptValue& object, SharedSoundPointer& out);
 
 #endif // hifi_Sound_h
diff --git a/libraries/avatars-renderer/CMakeLists.txt b/libraries/avatars-renderer/CMakeLists.txt
index 0175d1113ae..964af7085e9 100644
--- a/libraries/avatars-renderer/CMakeLists.txt
+++ b/libraries/avatars-renderer/CMakeLists.txt
@@ -1,11 +1,10 @@
 set(TARGET_NAME avatars-renderer)
-setup_hifi_library(Network Script)
-link_hifi_libraries(shared shaders gpu graphics animation material-networking model-networking script-engine render render-utils image entities-renderer physics)
+setup_hifi_library(Network)
+link_hifi_libraries(shared shaders gpu graphics animation material-networking model-networking render render-utils image entities-renderer physics recording)
 include_hifi_library_headers(avatars)
 include_hifi_library_headers(networking)
 include_hifi_library_headers(hfm)
 include_hifi_library_headers(model-serializers)
-include_hifi_library_headers(recording)
 include_hifi_library_headers(ktx)
 include_hifi_library_headers(procedural)
 include_hifi_library_headers(audio)
@@ -14,5 +13,6 @@ include_hifi_library_headers(octree)
 include_hifi_library_headers(task)
 include_hifi_library_headers(workload)
 include_hifi_library_headers(graphics-scripting) # for ScriptableModel.h
+include_hifi_library_headers(script-engine)
 
 target_bullet()
diff --git a/libraries/avatars/CMakeLists.txt b/libraries/avatars/CMakeLists.txt
index fc6d15cced9..17d0b1dd3d4 100644
--- a/libraries/avatars/CMakeLists.txt
+++ b/libraries/avatars/CMakeLists.txt
@@ -1,3 +1,3 @@
 set(TARGET_NAME avatars)
-setup_hifi_library(Network Script)
-link_hifi_libraries(shared networking)
+setup_hifi_library(Network)
+link_hifi_libraries(shared networking script-engine)
diff --git a/libraries/avatars/src/AvatarData.cpp b/libraries/avatars/src/AvatarData.cpp
index cfea4fedd53..373d1e30af3 100755
--- a/libraries/avatars/src/AvatarData.cpp
+++ b/libraries/avatars/src/AvatarData.cpp
@@ -35,6 +35,11 @@
 #include <StreamUtils.h>
 #include <UUID.h>
 #include <shared/JSONHelpers.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptManager.h>
+#include <ScriptValueIterator.h>
+#include <ScriptValueUtils.h>
 #include <ShapeInfo.h>
 #include <AudioHelpers.h>
 #include <Profile.h>
@@ -62,6 +67,14 @@ static const float DEFAULT_AVATAR_DENSITY = 1000.0f; // density of water
 
 #define ASSERT(COND)  do { if (!(COND)) { abort(); } } while(0)
 
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine().get();
+
+    registerAvatarTypes(scriptEngine);
+    scriptRegisterMetaType(scriptEngine, RayToAvatarIntersectionResultToScriptValue, RayToAvatarIntersectionResultFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, AvatarEntityMapToScriptValue, AvatarEntityMapFromScriptValue);
+});
+
 size_t AvatarDataPacket::maxFaceTrackerInfoSize(size_t numBlendshapeCoefficients) {
     return FACE_TRACKER_INFO_SIZE + numBlendshapeCoefficients * sizeof(float);
 }
@@ -2534,69 +2547,69 @@ QDataStream& operator>>(QDataStream& in, AttachmentData& attachment) {
 }
 
 void AttachmentDataObject::setModelURL(const QString& modelURL) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.modelURL = modelURL;
     thisObject() = engine()->toScriptValue(data);
 }
 
 QString AttachmentDataObject::getModelURL() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).modelURL.toString();
+    return scriptvalue_cast<AttachmentData>(thisObject()).modelURL.toString();
 }
 
 void AttachmentDataObject::setJointName(const QString& jointName) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.jointName = jointName;
     thisObject() = engine()->toScriptValue(data);
 }
 
 QString AttachmentDataObject::getJointName() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).jointName;
+    return scriptvalue_cast<AttachmentData>(thisObject()).jointName;
 }
 
 void AttachmentDataObject::setTranslation(const glm::vec3& translation) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.translation = translation;
     thisObject() = engine()->toScriptValue(data);
 }
 
 glm::vec3 AttachmentDataObject::getTranslation() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).translation;
+    return scriptvalue_cast<AttachmentData>(thisObject()).translation;
 }
 
 void AttachmentDataObject::setRotation(const glm::quat& rotation) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.rotation = rotation;
     thisObject() = engine()->toScriptValue(data);
 }
 
 glm::quat AttachmentDataObject::getRotation() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).rotation;
+    return scriptvalue_cast<AttachmentData>(thisObject()).rotation;
 }
 
 void AttachmentDataObject::setScale(float scale) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.scale = scale;
     thisObject() = engine()->toScriptValue(data);
 }
 
 float AttachmentDataObject::getScale() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).scale;
+    return scriptvalue_cast<AttachmentData>(thisObject()).scale;
 }
 
 void AttachmentDataObject::setIsSoft(bool isSoft) {
-    AttachmentData data = qscriptvalue_cast<AttachmentData>(thisObject());
+    AttachmentData data = scriptvalue_cast<AttachmentData>(thisObject());
     data.isSoft = isSoft;
     thisObject() = engine()->toScriptValue(data);
 }
 
 bool AttachmentDataObject::getIsSoft() const {
-    return qscriptvalue_cast<AttachmentData>(thisObject()).isSoft;
+    return scriptvalue_cast<AttachmentData>(thisObject()).isSoft;
 }
 
-void registerAvatarTypes(QScriptEngine* engine) {
-    qScriptRegisterSequenceMetaType<QVector<AttachmentData> >(engine);
+void registerAvatarTypes(ScriptEngine* engine) {
+    scriptRegisterSequenceMetaType<QVector<AttachmentData> >(engine);
     engine->setDefaultPrototype(qMetaTypeId<AttachmentData>(), engine->newQObject(
-        new AttachmentDataObject(), QScriptEngine::ScriptOwnership));
+        new AttachmentDataObject(), ScriptEngine::ScriptOwnership));
 }
 
 void AvatarData::setRecordingBasis(std::shared_ptr<Transform> recordingBasis) {
@@ -3140,40 +3153,41 @@ glm::mat4 AvatarData::getControllerRightHandMatrix() const {
  * @property {SubmeshIntersection} extraInfo - Extra information on the mesh intersected if mesh was picked against, 
  *     <code>{}</code> if it wasn't.
  */
-QScriptValue RayToAvatarIntersectionResultToScriptValue(QScriptEngine* engine, const RayToAvatarIntersectionResult& value) {
-    QScriptValue obj = engine->newObject();
+ScriptValue RayToAvatarIntersectionResultToScriptValue(ScriptEngine* engine, const RayToAvatarIntersectionResult& value) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("intersects", value.intersects);
-    QScriptValue avatarIDValue = quuidToScriptValue(engine, value.avatarID);
+    ScriptValue avatarIDValue = quuidToScriptValue(engine, value.avatarID);
     obj.setProperty("avatarID", avatarIDValue);
     obj.setProperty("distance", value.distance);
     obj.setProperty("face", boxFaceToString(value.face));
-    QScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
+    ScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
 
     obj.setProperty("intersection", intersection);
-    QScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
+    ScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
     obj.setProperty("surfaceNormal", surfaceNormal);
     obj.setProperty("jointIndex", value.jointIndex);
     obj.setProperty("extraInfo", engine->toScriptValue(value.extraInfo));
     return obj;
 }
 
-void RayToAvatarIntersectionResultFromScriptValue(const QScriptValue& object, RayToAvatarIntersectionResult& value) {
+bool RayToAvatarIntersectionResultFromScriptValue(const ScriptValue& object, RayToAvatarIntersectionResult& value) {
     value.intersects = object.property("intersects").toVariant().toBool();
-    QScriptValue avatarIDValue = object.property("avatarID");
+    ScriptValue avatarIDValue = object.property("avatarID");
     quuidFromScriptValue(avatarIDValue, value.avatarID);
     value.distance = object.property("distance").toVariant().toFloat();
     value.face = boxFaceFromString(object.property("face").toVariant().toString());
 
-    QScriptValue intersection = object.property("intersection");
+    ScriptValue intersection = object.property("intersection");
     if (intersection.isValid()) {
         vec3FromScriptValue(intersection, value.intersection);
     }
-    QScriptValue surfaceNormal = object.property("surfaceNormal");
+    ScriptValue surfaceNormal = object.property("surfaceNormal");
     if (surfaceNormal.isValid()) {
         vec3FromScriptValue(surfaceNormal, value.surfaceNormal);
     }
     value.jointIndex = object.property("jointIndex").toInt32();
     value.extraInfo = object.property("extraInfo").toVariant().toMap();
+    return true;
 }
 
 // these coefficients can be changed via JS for experimental tuning
@@ -3186,8 +3200,8 @@ float AvatarData::_avatarSortCoefficientAge { 1.0f };
  * An object with the UUIDs of avatar entities as keys and avatar entity properties objects as values.
  * @typedef {Object.<Uuid, Entities.EntityProperties>} AvatarEntityMap
  */
-QScriptValue AvatarEntityMapToScriptValue(QScriptEngine* engine, const AvatarEntityMap& value) {
-    QScriptValue obj = engine->newObject();
+ScriptValue AvatarEntityMapToScriptValue(ScriptEngine* engine, const AvatarEntityMap& value) {
+    ScriptValue obj = engine->newObject();
     for (auto entityID : value.keys()) {
         QByteArray entityProperties = value.value(entityID);
         QJsonDocument jsonEntityProperties = QJsonDocument::fromBinaryData(entityProperties);
@@ -3197,7 +3211,7 @@ QScriptValue AvatarEntityMapToScriptValue(QScriptEngine* engine, const AvatarEnt
 
         QVariant variantEntityProperties = jsonEntityProperties.toVariant();
         QVariantMap entityPropertiesMap = variantEntityProperties.toMap();
-        QScriptValue scriptEntityProperties = variantMapToScriptValue(entityPropertiesMap, *engine);
+        ScriptValue scriptEntityProperties = variantMapToScriptValue(entityPropertiesMap, *engine);
 
         QString key = entityID.toString();
         obj.setProperty(key, scriptEntityProperties);
@@ -3205,19 +3219,20 @@ QScriptValue AvatarEntityMapToScriptValue(QScriptEngine* engine, const AvatarEnt
     return obj;
 }
 
-void AvatarEntityMapFromScriptValue(const QScriptValue& object, AvatarEntityMap& value) {
-    QScriptValueIterator itr(object);
-    while (itr.hasNext()) {
-        itr.next();
-        QUuid EntityID = QUuid(itr.name());
+bool AvatarEntityMapFromScriptValue(const ScriptValue& object, AvatarEntityMap& value) {
+    ScriptValueIteratorPointer itr(object.newIterator());
+    while (itr->hasNext()) {
+        itr->next();
+        QUuid EntityID = QUuid(itr->name());
 
-        QScriptValue scriptEntityProperties = itr.value();
+        ScriptValue scriptEntityProperties = itr->value();
         QVariant variantEntityProperties = scriptEntityProperties.toVariant();
         QJsonDocument jsonEntityProperties = QJsonDocument::fromVariant(variantEntityProperties);
         QByteArray binaryEntityProperties = jsonEntityProperties.toBinaryData();
 
         value[EntityID] = binaryEntityProperties;
     }
+    return true;
 }
 
 const float AvatarData::DEFAULT_BUBBLE_SCALE = 2.4f; // magic number determined empirically
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index 70f20caa26f..7231e882dea 100755
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -32,8 +32,6 @@
 #include <QUuid>
 #include <QVariantMap>
 #include <QVector>
-#include <QtScript/QScriptable>
-#include <QtScript/QScriptValueIterator>
 #include <QReadWriteLock>
 
 #include <AvatarConstants.h>
@@ -50,12 +48,16 @@
 #include <ViewFrustum.h>
 #include <shared/RateCounter.h>
 #include <udt/SequenceNumber.h>
+#include <Scriptable.h>
+#include <ScriptValue.h>
 
 #include "AABox.h"
 #include "AvatarTraits.h"
 #include "HeadData.h"
 #include "PathUtils.h"
 
+class ScriptEngine;
+
 using AvatarSharedPointer = std::shared_ptr<AvatarData>;
 using AvatarWeakPointer = std::weak_ptr<AvatarData>;
 using AvatarHash = QHash<QUuid, AvatarSharedPointer>;
@@ -1924,7 +1926,7 @@ Q_DECLARE_METATYPE(AttachmentData)
 Q_DECLARE_METATYPE(QVector<AttachmentData>)
 
 /// Scriptable wrapper for attachments.
-class AttachmentDataObject : public QObject, protected QScriptable {
+class AttachmentDataObject : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(QString modelURL READ getModelURL WRITE setModelURL)
     Q_PROPERTY(QString jointName READ getJointName WRITE setJointName)
@@ -1954,7 +1956,7 @@ class AttachmentDataObject : public QObject, protected QScriptable {
     Q_INVOKABLE bool getIsSoft() const;
 };
 
-void registerAvatarTypes(QScriptEngine* engine);
+void registerAvatarTypes(ScriptEngine* engine);
 
 class RayToAvatarIntersectionResult {
 public:
@@ -1968,8 +1970,8 @@ class RayToAvatarIntersectionResult {
     QVariantMap extraInfo;
 };
 Q_DECLARE_METATYPE(RayToAvatarIntersectionResult)
-QScriptValue RayToAvatarIntersectionResultToScriptValue(QScriptEngine* engine, const RayToAvatarIntersectionResult& results);
-void RayToAvatarIntersectionResultFromScriptValue(const QScriptValue& object, RayToAvatarIntersectionResult& results);
+ScriptValue RayToAvatarIntersectionResultToScriptValue(ScriptEngine* engine, const RayToAvatarIntersectionResult& results);
+bool RayToAvatarIntersectionResultFromScriptValue(const ScriptValue& object, RayToAvatarIntersectionResult& results);
 
 // No JSDoc because it's not provided as a type to the script engine.
 class ParabolaToAvatarIntersectionResult {
@@ -1986,8 +1988,8 @@ class ParabolaToAvatarIntersectionResult {
 
 Q_DECLARE_METATYPE(AvatarEntityMap)
 
-QScriptValue AvatarEntityMapToScriptValue(QScriptEngine* engine, const AvatarEntityMap& value);
-void AvatarEntityMapFromScriptValue(const QScriptValue& object, AvatarEntityMap& value);
+ScriptValue AvatarEntityMapToScriptValue(ScriptEngine* engine, const AvatarEntityMap& value);
+bool AvatarEntityMapFromScriptValue(const ScriptValue& object, AvatarEntityMap& value);
 
 // faux joint indexes (-1 means invalid)
 const int NO_JOINT_INDEX = 65535; // -1
diff --git a/libraries/avatars/src/ScriptAvatarData.cpp b/libraries/avatars/src/ScriptAvatarData.cpp
index a67af18c40c..5335f8ab5b3 100644
--- a/libraries/avatars/src/ScriptAvatarData.cpp
+++ b/libraries/avatars/src/ScriptAvatarData.cpp
@@ -11,6 +11,26 @@
 
 #include "ScriptAvatarData.h"
 
+#include <ScriptEngineCast.h>
+#include <ScriptManager.h>
+
+ScriptValue avatarDataToScriptValue(ScriptEngine* engine, ScriptAvatarData* const& in) {
+    return engine->newQObject(in, ScriptEngine::ScriptOwnership);
+}
+
+bool avatarDataFromScriptValue(const ScriptValue& object, ScriptAvatarData*& out) {
+    // This is not implemented because there are no slots/properties that take an AvatarSharedPointer from a script
+    assert(false);
+    out = nullptr;
+    return false;
+}
+
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine().get();
+
+    scriptRegisterMetaType(scriptEngine, avatarDataToScriptValue, avatarDataFromScriptValue);
+});
+
 ScriptAvatarData::ScriptAvatarData(AvatarSharedPointer avatarData) :
     _avatarData(avatarData)
 {
diff --git a/libraries/baking/CMakeLists.txt b/libraries/baking/CMakeLists.txt
index 12fb1928771..bfb989c05c6 100644
--- a/libraries/baking/CMakeLists.txt
+++ b/libraries/baking/CMakeLists.txt
@@ -1,7 +1,7 @@
 set(TARGET_NAME baking)
 setup_hifi_library(Concurrent)
 
-link_hifi_libraries(shared shaders graphics networking procedural graphics-scripting ktx image model-serializers model-baker task)
+link_hifi_libraries(shared shaders graphics networking procedural graphics-scripting ktx image model-serializers model-baker task script-engine)
 include_hifi_library_headers(gpu)
 include_hifi_library_headers(hfm)
 include_hifi_library_headers(material-networking)
diff --git a/libraries/baking/src/MaterialBaker.cpp b/libraries/baking/src/MaterialBaker.cpp
index 540a2ee358b..68ca7316c40 100644
--- a/libraries/baking/src/MaterialBaker.cpp
+++ b/libraries/baking/src/MaterialBaker.cpp
@@ -20,6 +20,8 @@
 
 #include <SharedUtil.h>
 #include <PathUtils.h>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 
 #include <graphics-scripting/GraphicsScriptingInterface.h>
 
@@ -28,6 +30,7 @@ std::function<QThread*()> MaterialBaker::_getNextOvenWorkerThreadOperator;
 static int materialNum = 0;
 
 MaterialBaker::MaterialBaker(const QString& materialData, bool isURL, const QString& bakedOutputDir, QUrl destinationPath) :
+    _scriptEngine(newScriptEngine()),
     _materialData(materialData),
     _isURL(isURL),
     _destinationPath(destinationPath),
@@ -209,13 +212,15 @@ void MaterialBaker::outputMaterial() {
         if (_materialResource->parsedMaterials.networkMaterials.size() == 1) {
             auto networkMaterial = _materialResource->parsedMaterials.networkMaterials.begin();
             auto scriptableMaterial = scriptable::ScriptableMaterial(networkMaterial->second);
-            QVariant materialVariant = scriptable::scriptableMaterialToScriptValue(&_scriptEngine, scriptableMaterial).toVariant();
+            QVariant materialVariant =
+                scriptable::scriptableMaterialToScriptValue(_scriptEngine.get(), scriptableMaterial).toVariant();
             json.insert("materials", QJsonDocument::fromVariant(materialVariant).object());
         } else {
             QJsonArray materialArray;
             for (auto networkMaterial : _materialResource->parsedMaterials.networkMaterials) {
                 auto scriptableMaterial = scriptable::ScriptableMaterial(networkMaterial.second);
-                QVariant materialVariant = scriptable::scriptableMaterialToScriptValue(&_scriptEngine, scriptableMaterial).toVariant();
+                QVariant materialVariant =
+                    scriptable::scriptableMaterialToScriptValue(_scriptEngine.get(), scriptableMaterial).toVariant();
                 materialArray.append(QJsonDocument::fromVariant(materialVariant).object());
             }
             json.insert("materials", materialArray);
diff --git a/libraries/baking/src/MaterialBaker.h b/libraries/baking/src/MaterialBaker.h
index cb8289cfdb5..e3340083292 100644
--- a/libraries/baking/src/MaterialBaker.h
+++ b/libraries/baking/src/MaterialBaker.h
@@ -20,6 +20,7 @@
 #include "baking/TextureFileNamer.h"
 
 #include <procedural/ProceduralMaterialCache.h>
+#include <ScriptEngine.h>
 
 static const QString BAKED_MATERIAL_EXTENSION = ".baked.json";
 
@@ -69,7 +70,7 @@ private slots:
     QString _textureOutputDir;
     QString _bakedMaterialData;
 
-    QScriptEngine _scriptEngine;
+    ScriptEnginePointer _scriptEngine;
     static std::function<QThread*()> _getNextOvenWorkerThreadOperator;
     TextureFileNamer _textureFileNamer;
 
diff --git a/libraries/controllers/CMakeLists.txt b/libraries/controllers/CMakeLists.txt
index 9c6bbf4aaeb..ee1fc1d1630 100644
--- a/libraries/controllers/CMakeLists.txt
+++ b/libraries/controllers/CMakeLists.txt
@@ -1,10 +1,10 @@
 set(TARGET_NAME controllers)
 
 # set a default root dir for each of our optional externals if it was not passed
-setup_hifi_library(Script Qml)
+setup_hifi_library(Qml)
 
 # use setup_hifi_library macro to setup our project and link appropriate Qt modules
-link_hifi_libraries(shared)
+link_hifi_libraries(shared script-engine)
 include_hifi_library_headers(networking)
 
 GroupSources("src/controllers")
diff --git a/libraries/controllers/src/controllers/Pose.cpp b/libraries/controllers/src/controllers/Pose.cpp
index 75f747deaa4..1fad0b9c42d 100644
--- a/libraries/controllers/src/controllers/Pose.cpp
+++ b/libraries/controllers/src/controllers/Pose.cpp
@@ -8,10 +8,11 @@
 
 #include "Pose.h"
 
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValue>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 
 #include <RegisteredMetaTypes.h>
+#include <ScriptValueUtils.h>
 
 namespace controller {
 
@@ -39,8 +40,8 @@ namespace controller {
      * @property {Vec3} angularVelocity - Angular velocity in rad/s.
      * @property {boolean} valid - <code>true</code> if the pose is valid, otherwise <code>false</code>.
      */
-    QScriptValue Pose::toScriptValue(QScriptEngine* engine, const Pose& pose) {
-        QScriptValue obj = engine->newObject();
+    ScriptValue Pose::toScriptValue(ScriptEngine* engine, const Pose& pose) {
+        ScriptValue obj = engine->newObject();
         obj.setProperty("translation", vec3ToScriptValue(engine, pose.translation));
         obj.setProperty("rotation", quatToScriptValue(engine, pose.rotation));
         obj.setProperty("velocity", vec3ToScriptValue(engine, pose.velocity));
@@ -49,7 +50,7 @@ namespace controller {
         return obj;
     }
 
-    void Pose::fromScriptValue(const QScriptValue& object, Pose& pose) {
+    bool Pose::fromScriptValue(const ScriptValue& object, Pose& pose) {
         auto translation = object.property("translation");
         auto rotation = object.property("rotation");
         auto velocity = object.property("velocity");
@@ -66,6 +67,7 @@ namespace controller {
         } else {
             pose.valid = false;
         }
+        return true;
     }
 
     Pose Pose::transform(const glm::mat4& mat) const {
diff --git a/libraries/controllers/src/controllers/Pose.h b/libraries/controllers/src/controllers/Pose.h
index 186bbdd7339..a1bcbffd2d0 100644
--- a/libraries/controllers/src/controllers/Pose.h
+++ b/libraries/controllers/src/controllers/Pose.h
@@ -10,9 +10,9 @@
 #pragma once
 #ifndef hifi_controllers_Pose_h
 #define hifi_controllers_Pose_h
+#include <ScriptValue.h>
 
-class QScriptEngine;
-class QScriptValue;
+class ScriptEngine;
 
 #include <GLMHelpers.h>
 
@@ -44,8 +44,8 @@ namespace controller {
         Pose transform(const glm::mat4& mat) const;
         Pose postTransform(const glm::mat4& mat) const;
 
-        static QScriptValue toScriptValue(QScriptEngine* engine, const Pose& event);
-        static void fromScriptValue(const QScriptValue& object, Pose& event);
+        static ScriptValue toScriptValue(ScriptEngine* engine, const Pose& event);
+        static bool fromScriptValue(const ScriptValue& object, Pose& event);
     };
 }
 
diff --git a/libraries/controllers/src/controllers/ScriptingInterface.cpp b/libraries/controllers/src/controllers/ScriptingInterface.cpp
index e9a831859da..2187f4bc996 100644
--- a/libraries/controllers/src/controllers/ScriptingInterface.cpp
+++ b/libraries/controllers/src/controllers/ScriptingInterface.cpp
@@ -25,6 +25,26 @@
 #include "InputDevice.h"
 #include "InputRecorder.h"
 
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
+
+
+ScriptValue inputControllerToScriptValue(ScriptEngine* engine, controller::InputController* const& in) {
+    return engine->newQObject(in, ScriptEngine::QtOwnership);
+}
+
+bool inputControllerFromScriptValue(const ScriptValue& object, controller::InputController*& out) {
+    out = qobject_cast<controller::InputController*>(object.toQObject());
+    return true;
+}
+
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine().get();
+
+    scriptRegisterMetaType(scriptEngine, inputControllerToScriptValue, inputControllerFromScriptValue);
+});
 
 static QRegularExpression SANITIZE_NAME_EXPRESSION{ "[\\(\\)\\.\\s]" };
 
diff --git a/libraries/controllers/src/controllers/ScriptingInterface.h b/libraries/controllers/src/controllers/ScriptingInterface.h
index 969b2d19d21..06b684c7acf 100644
--- a/libraries/controllers/src/controllers/ScriptingInterface.h
+++ b/libraries/controllers/src/controllers/ScriptingInterface.h
@@ -29,7 +29,6 @@
 #include <QMutex>
 
 #include <QtQml/QJSValue>
-#include <QtScript/QScriptValue>
 
 #include <DependencyManager.h>
 #include <StreamUtils.h>
diff --git a/libraries/controllers/src/controllers/UserInputMapper.cpp b/libraries/controllers/src/controllers/UserInputMapper.cpp
index 6a46dea7d94..d1fca933f54 100755
--- a/libraries/controllers/src/controllers/UserInputMapper.cpp
+++ b/libraries/controllers/src/controllers/UserInputMapper.cpp
@@ -26,6 +26,10 @@
 #include "StateController.h"
 #include "InputRecorder.h"
 #include "Logging.h"
+#include "ScriptValueUtils.h"
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptValue.h>
 
 #include "impl/conditionals/AndConditional.h"
 #include "impl/conditionals/NotConditional.h"
@@ -388,17 +392,17 @@ int inputPairMetaTypeId = qRegisterMetaType<Input::NamedPair>();
 int poseMetaTypeId = qRegisterMetaType<controller::Pose>("Pose");
 int handMetaTypeId = qRegisterMetaType<controller::Hand>();
 
-QScriptValue inputToScriptValue(QScriptEngine* engine, const Input& input);
-void inputFromScriptValue(const QScriptValue& object, Input& input);
-QScriptValue actionToScriptValue(QScriptEngine* engine, const Action& action);
-void actionFromScriptValue(const QScriptValue& object, Action& action);
-QScriptValue inputPairToScriptValue(QScriptEngine* engine, const Input::NamedPair& inputPair);
-void inputPairFromScriptValue(const QScriptValue& object, Input::NamedPair& inputPair);
-QScriptValue handToScriptValue(QScriptEngine* engine, const controller::Hand& hand);
-void handFromScriptValue(const QScriptValue& object, controller::Hand& hand);
-
-QScriptValue inputToScriptValue(QScriptEngine* engine, const Input& input) {
-    QScriptValue obj = engine->newObject();
+ScriptValue inputToScriptValue(ScriptEngine* engine, const Input& input);
+bool inputFromScriptValue(const ScriptValue& object, Input& input);
+ScriptValue actionToScriptValue(ScriptEngine* engine, const Action& action);
+bool actionFromScriptValue(const ScriptValue& object, Action& action);
+ScriptValue inputPairToScriptValue(ScriptEngine* engine, const Input::NamedPair& inputPair);
+bool inputPairFromScriptValue(const ScriptValue& object, Input::NamedPair& inputPair);
+ScriptValue handToScriptValue(ScriptEngine* engine, const controller::Hand& hand);
+bool handFromScriptValue(const ScriptValue& object, controller::Hand& hand);
+
+ScriptValue inputToScriptValue(ScriptEngine* engine, const Input& input) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("device", input.getDevice());
     obj.setProperty("channel", input.getChannel());
     obj.setProperty("type", (unsigned short)input.getType());
@@ -406,51 +410,55 @@ QScriptValue inputToScriptValue(QScriptEngine* engine, const Input& input) {
     return obj;
 }
 
-void inputFromScriptValue(const QScriptValue& object, Input& input) {
+bool inputFromScriptValue(const ScriptValue& object, Input& input) {
     input.id = object.property("id").toInt32();
+    return true;
 }
 
-QScriptValue actionToScriptValue(QScriptEngine* engine, const Action& action) {
-    QScriptValue obj = engine->newObject();
+ScriptValue actionToScriptValue(ScriptEngine* engine, const Action& action) {
+    ScriptValue obj = engine->newObject();
     auto userInputMapper = DependencyManager::get<UserInputMapper>();
     obj.setProperty("action", (int)action);
     obj.setProperty("actionName", userInputMapper->getActionName(action));
     return obj;
 }
 
-void actionFromScriptValue(const QScriptValue& object, Action& action) {
+bool actionFromScriptValue(const ScriptValue& object, Action& action) {
     action = Action(object.property("action").toVariant().toInt());
+    return true;
 }
 
-QScriptValue inputPairToScriptValue(QScriptEngine* engine, const Input::NamedPair& inputPair) {
-    QScriptValue obj = engine->newObject();
+ScriptValue inputPairToScriptValue(ScriptEngine* engine, const Input::NamedPair& inputPair) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("input", inputToScriptValue(engine, inputPair.first));
     obj.setProperty("inputName", inputPair.second);
     return obj;
 }
 
-void inputPairFromScriptValue(const QScriptValue& object, Input::NamedPair& inputPair) {
+bool inputPairFromScriptValue(const ScriptValue& object, Input::NamedPair& inputPair) {
     inputFromScriptValue(object.property("input"), inputPair.first);
     inputPair.second = QString(object.property("inputName").toVariant().toString());
+    return true;
 }
 
-QScriptValue handToScriptValue(QScriptEngine* engine, const controller::Hand& hand) {
-    return engine->newVariant((int)hand);
+ScriptValue handToScriptValue(ScriptEngine* engine, const controller::Hand& hand) {
+    return engine->newValue((int)hand);
 }
 
-void handFromScriptValue(const QScriptValue& object, controller::Hand& hand) {
+bool handFromScriptValue(const ScriptValue& object, controller::Hand& hand) {
     hand = Hand(object.toVariant().toInt());
+    return true;
 }
 
-void UserInputMapper::registerControllerTypes(QScriptEngine* engine) {
-    qScriptRegisterSequenceMetaType<QVector<Action> >(engine);
-    qScriptRegisterSequenceMetaType<Input::NamedVector>(engine);
-    qScriptRegisterMetaType(engine, actionToScriptValue, actionFromScriptValue);
-    qScriptRegisterMetaType(engine, inputToScriptValue, inputFromScriptValue);
-    qScriptRegisterMetaType(engine, inputPairToScriptValue, inputPairFromScriptValue);
-    qScriptRegisterMetaType(engine, handToScriptValue, handFromScriptValue);
+void UserInputMapper::registerControllerTypes(ScriptEngine* engine) {
+    scriptRegisterSequenceMetaType<QVector<Action> >(engine);
+    scriptRegisterSequenceMetaType<Input::NamedVector>(engine);
+    scriptRegisterMetaType(engine, actionToScriptValue, actionFromScriptValue);
+    scriptRegisterMetaType(engine, inputToScriptValue, inputFromScriptValue);
+    scriptRegisterMetaType(engine, inputPairToScriptValue, inputPairFromScriptValue);
+    scriptRegisterMetaType(engine, handToScriptValue, handFromScriptValue);
 
-    qScriptRegisterMetaType(engine, Pose::toScriptValue, Pose::fromScriptValue);
+    scriptRegisterMetaType(engine, Pose::toScriptValue, Pose::fromScriptValue);
 }
 
 Input UserInputMapper::makeStandardInput(controller::StandardButtonChannel button) {
@@ -658,7 +666,7 @@ Endpoint::Pointer UserInputMapper::endpointFor(const QJSValue& endpoint) {
     return Endpoint::Pointer();
 }
 
-Endpoint::Pointer UserInputMapper::endpointFor(const QScriptValue& endpoint) {
+Endpoint::Pointer UserInputMapper::endpointFor(const ScriptValue& endpoint) {
     if (endpoint.isNumber()) {
         return endpointFor(Input(endpoint.toInt32()));
     }
@@ -672,7 +680,7 @@ Endpoint::Pointer UserInputMapper::endpointFor(const QScriptValue& endpoint) {
         int length = endpoint.property("length").toInteger();
         Endpoint::List children;
         for (int i = 0; i < length; i++) {
-            QScriptValue arrayItem = endpoint.property(i);
+            ScriptValue arrayItem = endpoint.property(i);
             Endpoint::Pointer destination = endpointFor(arrayItem);
             if (!destination) {
                 return Endpoint::Pointer();
@@ -883,7 +891,7 @@ Conditional::Pointer UserInputMapper::conditionalFor(const QJSValue& condition)
     return Conditional::Pointer();
 }
 
-Conditional::Pointer UserInputMapper::conditionalFor(const QScriptValue& condition) {
+Conditional::Pointer UserInputMapper::conditionalFor(const ScriptValue& condition) {
     if (condition.isArray()) {
         int length = condition.property("length").toInteger();
         Conditional::List children;
diff --git a/libraries/controllers/src/controllers/UserInputMapper.h b/libraries/controllers/src/controllers/UserInputMapper.h
index ee8b34193fb..3fcce461c01 100644
--- a/libraries/controllers/src/controllers/UserInputMapper.h
+++ b/libraries/controllers/src/controllers/UserInputMapper.h
@@ -18,7 +18,6 @@
 #include <mutex>
 
 #include <QtQml/QJSValue>
-#include <QtScript/QScriptValue>
 
 #include <DependencyManager.h>
 #include <RegisteredMetaTypes.h>
@@ -32,6 +31,9 @@
 #include "Actions.h"
 #include "StateController.h"
 
+class ScriptEngine;
+class ScriptValue;
+
 namespace controller {
 
     class RouteBuilderProxy;
@@ -64,7 +66,7 @@ namespace controller {
         virtual ~UserInputMapper();
 
 
-        static void registerControllerTypes(QScriptEngine* engine);
+        static void registerControllerTypes(ScriptEngine* engine);
 
         void registerDevice(InputDevice::Pointer device);
         InputDevice::Pointer getDevice(const Input& input);
@@ -164,10 +166,10 @@ namespace controller {
         void enableMapping(const MappingPointer& mapping);
         void disableMapping(const MappingPointer& mapping);
         EndpointPointer endpointFor(const QJSValue& endpoint);
-        EndpointPointer endpointFor(const QScriptValue& endpoint);
+        EndpointPointer endpointFor(const ScriptValue& endpoint);
         EndpointPointer compositeEndpointFor(EndpointPointer first, EndpointPointer second);
         ConditionalPointer conditionalFor(const QJSValue& endpoint);
-        ConditionalPointer conditionalFor(const QScriptValue& endpoint);
+        ConditionalPointer conditionalFor(const ScriptValue& endpoint);
         ConditionalPointer conditionalFor(const Input& endpoint) const;
 
         MappingPointer parseMapping(const QJsonValue& json);
diff --git a/libraries/controllers/src/controllers/impl/Endpoint.h b/libraries/controllers/src/controllers/impl/Endpoint.h
index 692e427e165..00a4c264a9b 100644
--- a/libraries/controllers/src/controllers/impl/Endpoint.h
+++ b/libraries/controllers/src/controllers/impl/Endpoint.h
@@ -20,8 +20,6 @@
 #include "../Input.h"
 #include "../Pose.h"
 
-class QScriptValue;
-
 namespace controller {
     /*
     * Encapsulates a particular input / output,
diff --git a/libraries/controllers/src/controllers/impl/Filter.cpp b/libraries/controllers/src/controllers/impl/Filter.cpp
index f230fb83dc9..2a175137036 100644
--- a/libraries/controllers/src/controllers/impl/Filter.cpp
+++ b/libraries/controllers/src/controllers/impl/Filter.cpp
@@ -9,7 +9,6 @@
 #include "Filter.h"
 
 #include <QtCore/QObject>
-#include <QtScript/QScriptValue>
 
 #include <QtCore/QJsonObject>
 #include <QtCore/QJsonArray>
diff --git a/libraries/controllers/src/controllers/impl/MappingBuilderProxy.cpp b/libraries/controllers/src/controllers/impl/MappingBuilderProxy.cpp
index ff4725fb667..64c837f34b7 100644
--- a/libraries/controllers/src/controllers/impl/MappingBuilderProxy.cpp
+++ b/libraries/controllers/src/controllers/impl/MappingBuilderProxy.cpp
@@ -17,6 +17,7 @@
 #include "RouteBuilderProxy.h"
 #include "../ScriptingInterface.h"
 #include "../Logging.h"
+#include <ScriptValue.h>
 
 using namespace controller;
 
@@ -26,7 +27,7 @@ QObject* MappingBuilderProxy::fromQml(const QJSValue& source) {
     return from(sourceEndpoint);
 }
 
-QObject* MappingBuilderProxy::from(const QScriptValue& source) {
+QObject* MappingBuilderProxy::from(const ScriptValue& source) {
     qCDebug(controllers) << "Creating new Route builder proxy from " << source.toString();
     auto sourceEndpoint = _parent.endpointFor(source);
     return from(sourceEndpoint);
@@ -49,7 +50,7 @@ QObject* MappingBuilderProxy::makeAxisQml(const QJSValue& source1, const QJSValu
     return from(_parent.compositeEndpointFor(source1Endpoint, source2Endpoint));
 }
 
-QObject* MappingBuilderProxy::makeAxis(const QScriptValue& source1, const QScriptValue& source2) {
+QObject* MappingBuilderProxy::makeAxis(const ScriptValue& source1, const ScriptValue& source2) {
     auto source1Endpoint = _parent.endpointFor(source1);
     auto source2Endpoint = _parent.endpointFor(source2);
     return from(_parent.compositeEndpointFor(source1Endpoint, source2Endpoint));
diff --git a/libraries/controllers/src/controllers/impl/MappingBuilderProxy.h b/libraries/controllers/src/controllers/impl/MappingBuilderProxy.h
index bf943f373f7..8e60386110f 100644
--- a/libraries/controllers/src/controllers/impl/MappingBuilderProxy.h
+++ b/libraries/controllers/src/controllers/impl/MappingBuilderProxy.h
@@ -16,8 +16,8 @@
 #include "Endpoint.h"
 
 class QJSValue;
-class QScriptValue;
 class QJsonValue;
+class ScriptValue;
 
 namespace controller {
 
@@ -165,7 +165,7 @@ class MappingBuilderProxy : public QObject {
      *     of the route data. If a function, it must return a number or a {@link Pose} value as the route data.
      * @returns {RouteObject} A route ready for mapping to an action or function using {@link RouteObject} methods.
      */
-    Q_INVOKABLE QObject* from(const QScriptValue& source);
+    Q_INVOKABLE QObject* from(const ScriptValue& source);
 
     /*@jsdoc
      * Creates a new {@link RouteObject} from two numeric {@link Controller.Hardware} outputs, one applied in the negative 
@@ -187,7 +187,7 @@ class MappingBuilderProxy : public QObject {
      *     Controller.disableMapping(MAPPING_NAME);
      * });
      */
-    Q_INVOKABLE QObject* makeAxis(const QScriptValue& source1, const QScriptValue& source2);
+    Q_INVOKABLE QObject* makeAxis(const ScriptValue& source1, const ScriptValue& source2);
 
     /*@jsdoc
      * Enables or disables the mapping. When enabled, the routes in the mapping take effect.
diff --git a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
index 91027a1a9c8..c747e920a4b 100644
--- a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
+++ b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.cpp
@@ -17,6 +17,7 @@
 #include "MappingBuilderProxy.h"
 #include "../ScriptingInterface.h"
 #include "../Logging.h"
+#include <ScriptValue.h>
 
 #include "filters/ClampFilter.h"
 #include "filters/ConstrainToIntegerFilter.h"
@@ -43,7 +44,7 @@ void RouteBuilderProxy::toQml(const QJSValue& destination) {
     return to(destinationEndpoint);
 }
 
-void RouteBuilderProxy::to(const QScriptValue& destination) {
+void RouteBuilderProxy::to(const ScriptValue& destination) {
     qCDebug(controllers) << "Completing route " << destination.toString();
     auto destinationEndpoint = _parent.endpointFor(destination);
     return to(destinationEndpoint);
@@ -65,7 +66,7 @@ QObject* RouteBuilderProxy::peek(bool enable) {
     return this;
 }
 
-QObject* RouteBuilderProxy::when(const QScriptValue& expression) {
+QObject* RouteBuilderProxy::when(const ScriptValue& expression) {
     // FIXME: Support "!" conditional in simple expression and array expression.
     // Note that "!" is supported when parsing a JSON file, in UserInputMapper::parseConditional().
     auto newConditional = _parent.conditionalFor(expression);
diff --git a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
index d9fec2f8084..c242c9597a3 100644
--- a/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
+++ b/libraries/controllers/src/controllers/impl/RouteBuilderProxy.h
@@ -18,8 +18,8 @@
 #include "../UserInputMapper.h"
 
 class QJSValue;
-class QScriptValue;
 class QJsonValue;
+class ScriptValue;
 
 namespace controller {
 
@@ -115,7 +115,7 @@ class RouteBuilderProxy : public QObject {
          *     Controller.disableMapping(MAPPING_NAME);
          * });
          */
-        Q_INVOKABLE void to(const QScriptValue& destination);
+        Q_INVOKABLE void to(const ScriptValue& destination);
 
         /*@jsdoc
          * Enables or disables writing debug information for a route to the program log.
@@ -193,7 +193,7 @@ class RouteBuilderProxy : public QObject {
          *     Controller.disableMapping(MAPPING_NAME);
          * });
          */
-        Q_INVOKABLE QObject* when(const QScriptValue& expression);
+        Q_INVOKABLE QObject* when(const ScriptValue& expression);
 
         /*@jsdoc
          * Filters numeric route values to lie between two values; values outside this range are not passed on through the 
diff --git a/libraries/controllers/src/controllers/impl/conditionals/ScriptConditional.h b/libraries/controllers/src/controllers/impl/conditionals/ScriptConditional.h
index 800692d02c7..156fdaff44b 100644
--- a/libraries/controllers/src/controllers/impl/conditionals/ScriptConditional.h
+++ b/libraries/controllers/src/controllers/impl/conditionals/ScriptConditional.h
@@ -11,8 +11,7 @@
 #define hifi_Controllers_ScriptConditional_h
 
 #include <QtCore/QObject>
-
-#include <QtScript/QScriptValue>
+#include <ScriptValue.h>
 
 #include "../Conditional.h"
 
@@ -21,12 +20,12 @@ namespace controller {
 class ScriptConditional : public QObject, public Conditional {
     Q_OBJECT;
 public:
-    ScriptConditional(const QScriptValue& callable) : _callable(callable) { }
+    ScriptConditional(const ScriptValue& callable) : _callable(callable) {}
     virtual bool satisfied() override;
 protected:
     Q_INVOKABLE void updateValue();
 private:
-    QScriptValue _callable;
+    ScriptValue _callable;
     bool _lastValue { false };
 };
 
diff --git a/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.cpp b/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.cpp
index 9f971d2f04c..8ed5222160c 100644
--- a/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.cpp
+++ b/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.cpp
@@ -11,11 +11,13 @@
 
 #include <QtCore/QThread>
 
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 #include <StreamUtils.h>
 
 using namespace controller;
 
-QString formatException(const QScriptValue& exception) {
+QString formatException(const ScriptValue& exception) {
     QString note { "UncaughtException" };
     QString result;
 
@@ -45,7 +47,7 @@ void ScriptEndpoint::updateValue() {
         return;
     }
 
-    QScriptValue result = _callable.call();
+    ScriptValue result = _callable.call();
     if (result.isError()) {
         // print JavaScript exception
         qCDebug(controllers).noquote() << formatException(result);
@@ -73,8 +75,9 @@ void ScriptEndpoint::internalApply(float value, int sourceID) {
             Q_ARG(int, sourceID));
         return;
     }
-    QScriptValue result = _callable.call(QScriptValue(),
-        QScriptValueList({ QScriptValue(value), QScriptValue(sourceID) }));
+    ScriptEnginePointer engine = _callable.engine();
+    ScriptValue result = _callable.call(ScriptValue(),
+        ScriptValueList({ engine->newValue(value), engine->newValue(sourceID) }));
     if (result.isError()) {
         // print JavaScript exception
         qCDebug(controllers).noquote() << formatException(result);
@@ -91,7 +94,7 @@ void ScriptEndpoint::updatePose() {
         QMetaObject::invokeMethod(this, "updatePose", Qt::QueuedConnection);
         return;
     }
-    QScriptValue result = _callable.call();
+    ScriptValue result = _callable.call();
     if (result.isError()) {
         // print JavaScript exception
         qCDebug(controllers).noquote() << formatException(result);
@@ -114,8 +117,9 @@ void ScriptEndpoint::internalApply(const Pose& newPose, int sourceID) {
             Q_ARG(int, sourceID));
         return;
     }
-    QScriptValue result = _callable.call(QScriptValue(),
-        QScriptValueList({ Pose::toScriptValue(_callable.engine(), newPose), QScriptValue(sourceID) }));
+    ScriptEnginePointer engine = _callable.engine();
+    ScriptValue result = _callable.call(ScriptValue(),
+        ScriptValueList({ Pose::toScriptValue(engine.get(), newPose), engine->newValue(sourceID) }));
     if (result.isError()) {
         // print JavaScript exception
         qCDebug(controllers).noquote() << formatException(result);
diff --git a/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.h b/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.h
index 1aa1746b249..327cb40eaaf 100644
--- a/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.h
+++ b/libraries/controllers/src/controllers/impl/endpoints/ScriptEndpoint.h
@@ -10,7 +10,7 @@
 #ifndef hifi_Controllers_ScriptEndpoint_h
 #define hifi_Controllers_ScriptEndpoint_h
 
-#include <QtScript/QScriptValue>
+#include <ScriptValue.h>
 
 #include "../Endpoint.h"
 
@@ -20,7 +20,7 @@ class ScriptEndpoint : public Endpoint {
     Q_OBJECT;
 public:
     using Endpoint::apply;
-    ScriptEndpoint(const QScriptValue& callable)
+    ScriptEndpoint(const ScriptValue& callable)
         : Endpoint(Input::INVALID_INPUT), _callable(callable) {
     }
 
@@ -39,7 +39,7 @@ class ScriptEndpoint : public Endpoint {
     Q_INVOKABLE void updatePose();
     Q_INVOKABLE virtual void internalApply(const Pose& newValue, int sourceID);
 private:
-    QScriptValue _callable;
+    ScriptValue _callable;
     float _lastValueRead { 0.0f };
     AxisValue _lastValueWritten { 0.0f, 0, false };
 
diff --git a/libraries/entities-renderer/CMakeLists.txt b/libraries/entities-renderer/CMakeLists.txt
index 67f34f4831e..54e108247a1 100644
--- a/libraries/entities-renderer/CMakeLists.txt
+++ b/libraries/entities-renderer/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME entities-renderer)
-setup_hifi_library(Network Script)
-link_hifi_libraries(shared workload gpu shaders procedural graphics material-networking model-networking script-engine render render-utils image qml ui pointers)
+setup_hifi_library(Network)
+link_hifi_libraries(shared workload gpu shaders procedural graphics material-networking model-networking script-engine render render-utils image qml ui pointers entities)
 include_hifi_library_headers(networking)
 include_hifi_library_headers(gl)
 include_hifi_library_headers(ktx)
@@ -10,7 +10,6 @@ include_hifi_library_headers(physics)
 include_hifi_library_headers(animation)
 include_hifi_library_headers(hfm)
 include_hifi_library_headers(model-serializers)
-include_hifi_library_headers(entities)
 include_hifi_library_headers(avatars)
 include_hifi_library_headers(controllers)
 include_hifi_library_headers(task)
diff --git a/libraries/entities-renderer/src/EntityTreeRenderer.cpp b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
index cdca420c32a..e0b0e934dc5 100644
--- a/libraries/entities-renderer/src/EntityTreeRenderer.cpp
+++ b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
@@ -16,7 +16,6 @@
 #include <queue>
 
 #include <QEventLoop>
-#include <QScriptSyntaxCheckResult>
 #include <QThreadPool>
 
 #include <shared/QtHelpers.h>
@@ -31,6 +30,7 @@
 #include <Rig.h>
 #include <SceneScriptingInterface.h>
 #include <ScriptEngines.h>
+#include <ScriptManager.h>
 #include <EntitySimulation.h>
 #include <ZoneRenderer.h>
 #include <PhysicalEntitySimulation.h>
@@ -159,45 +159,55 @@ render::ItemID EntityTreeRenderer::renderableIdForEntityId(const EntityItemID& i
 
 int EntityTreeRenderer::_entitiesScriptEngineCount = 0;
 
-void EntityTreeRenderer::setupEntityScriptEngineSignals(const ScriptEnginePointer& scriptEngine) {
+void EntityTreeRenderer::setupEntityScriptEngineSignals(const ScriptManagerPointer& scriptManager) {
     auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
 
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mousePressOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "mousePressOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mousePressOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "mousePressOnEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseDoublePressOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "mouseDoublePressOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseDoublePressOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "mouseDoublePressOnEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseMoveOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "mouseMoveOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseMoveOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "mouseMoveOnEntity", event);
         // FIXME: this is a duplicate of mouseMoveOnEntity, but it seems like some scripts might use this naming
-        scriptEngine->callEntityScriptMethod(entityID, "mouseMoveEvent", event);
+        scriptManager->callEntityScriptMethod(entityID, "mouseMoveEvent", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseReleaseOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "mouseReleaseOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::mouseReleaseOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "mouseReleaseOnEntity", event);
     });
 
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::clickDownOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "clickDownOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::clickDownOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "clickDownOnEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::holdingClickOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "holdingClickOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::holdingClickOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "holdingClickOnEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::clickReleaseOnEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "clickReleaseOnEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::clickReleaseOnEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "clickReleaseOnEntity", event);
     });
 
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverEnterEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "hoverEnterEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverEnterEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "hoverEnterEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverOverEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "hoverOverEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverOverEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "hoverOverEntity", event);
     });
-    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverLeaveEntity, scriptEngine.data(), [&](const EntityItemID& entityID, const PointerEvent& event) {
-        scriptEngine->callEntityScriptMethod(entityID, "hoverLeaveEntity", event);
+    connect(entityScriptingInterface.data(), &EntityScriptingInterface::hoverLeaveEntity, scriptManager.get(),
+            [&](const EntityItemID& entityID, const PointerEvent& event) {
+        scriptManager->callEntityScriptMethod(entityID, "hoverLeaveEntity", event);
     });
 
-    connect(scriptEngine.data(), &ScriptEngine::entityScriptPreloadFinished, [&](const EntityItemID& entityID) {
+    connect(scriptManager.get(), &ScriptManager::entityScriptPreloadFinished, [&](const EntityItemID& entityID) {
         EntityItemPointer entity = getTree()->findEntityByID(entityID);
         if (entity) {
             entity->setScriptHasFinishedPreload(true);
@@ -206,51 +216,51 @@ void EntityTreeRenderer::setupEntityScriptEngineSignals(const ScriptEnginePointe
 }
 
 void EntityTreeRenderer::resetPersistentEntitiesScriptEngine() {
-    if (_persistentEntitiesScriptEngine) {
-        _persistentEntitiesScriptEngine->unloadAllEntityScripts(true);
-        _persistentEntitiesScriptEngine->stop();
-        _persistentEntitiesScriptEngine->waitTillDoneRunning();
-        _persistentEntitiesScriptEngine->disconnectNonEssentialSignals();
+    if (_persistentEntitiesScriptManager) {
+        _persistentEntitiesScriptManager->unloadAllEntityScripts(true);
+        _persistentEntitiesScriptManager->stop();
+        _persistentEntitiesScriptManager->waitTillDoneRunning();
+        _persistentEntitiesScriptManager->disconnectNonEssentialSignals();
     }
-    _persistentEntitiesScriptEngine = scriptEngineFactory(ScriptEngine::ENTITY_CLIENT_SCRIPT, NO_SCRIPT,
+    _persistentEntitiesScriptManager = scriptManagerFactory(ScriptManager::ENTITY_CLIENT_SCRIPT, NO_SCRIPT,
                                                 QString("about:Entities %1").arg(++_entitiesScriptEngineCount));
-    DependencyManager::get<ScriptEngines>()->runScriptInitializers(_persistentEntitiesScriptEngine);
-    _persistentEntitiesScriptEngine->runInThread();
-    auto entitiesScriptEngineProvider = qSharedPointerCast<EntitiesScriptEngineProvider>(_persistentEntitiesScriptEngine);
+    DependencyManager::get<ScriptEngines>()->runScriptInitializers(_persistentEntitiesScriptManager);
+    _persistentEntitiesScriptManager->runInThread();
+    std::shared_ptr<EntitiesScriptEngineProvider> entitiesScriptEngineProvider = _persistentEntitiesScriptManager;
     auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
     entityScriptingInterface->setPersistentEntitiesScriptEngine(entitiesScriptEngineProvider);
 
-    setupEntityScriptEngineSignals(_persistentEntitiesScriptEngine);
+    setupEntityScriptEngineSignals(_persistentEntitiesScriptManager);
 }
 
 void EntityTreeRenderer::resetNonPersistentEntitiesScriptEngine() {
-    if (_nonPersistentEntitiesScriptEngine) {
-        _nonPersistentEntitiesScriptEngine->unloadAllEntityScripts(true);
-        _nonPersistentEntitiesScriptEngine->stop();
-        _nonPersistentEntitiesScriptEngine->waitTillDoneRunning();
-        _nonPersistentEntitiesScriptEngine->disconnectNonEssentialSignals();
+    if (_nonPersistentEntitiesScriptManager) {
+        _nonPersistentEntitiesScriptManager->unloadAllEntityScripts(true);
+        _nonPersistentEntitiesScriptManager->stop();
+        _nonPersistentEntitiesScriptManager->waitTillDoneRunning();
+        _nonPersistentEntitiesScriptManager->disconnectNonEssentialSignals();
     }
-    _nonPersistentEntitiesScriptEngine = scriptEngineFactory(ScriptEngine::ENTITY_CLIENT_SCRIPT, NO_SCRIPT,
+    _nonPersistentEntitiesScriptManager = scriptManagerFactory(ScriptManager::ENTITY_CLIENT_SCRIPT, NO_SCRIPT,
                                                 QString("about:Entities %1").arg(++_entitiesScriptEngineCount));
-    DependencyManager::get<ScriptEngines>()->runScriptInitializers(_nonPersistentEntitiesScriptEngine);
-    _nonPersistentEntitiesScriptEngine->runInThread();
-    auto entitiesScriptEngineProvider = qSharedPointerCast<EntitiesScriptEngineProvider>(_nonPersistentEntitiesScriptEngine);
+    DependencyManager::get<ScriptEngines>()->runScriptInitializers(_nonPersistentEntitiesScriptManager);
+    _nonPersistentEntitiesScriptManager->runInThread();
+    std::shared_ptr<EntitiesScriptEngineProvider> entitiesScriptEngineProvider = _nonPersistentEntitiesScriptManager;
     DependencyManager::get<EntityScriptingInterface>()->setNonPersistentEntitiesScriptEngine(entitiesScriptEngineProvider);
 
-    setupEntityScriptEngineSignals(_nonPersistentEntitiesScriptEngine);
+    setupEntityScriptEngineSignals(_nonPersistentEntitiesScriptManager);
 }
 
 void EntityTreeRenderer::stopDomainAndNonOwnedEntities() {
     leaveDomainAndNonOwnedEntities();
     // unload and stop the engine
-    if (_nonPersistentEntitiesScriptEngine) {
-        QList<EntityItemID> entitiesWithEntityScripts = _nonPersistentEntitiesScriptEngine->getListOfEntityScriptIDs();
+    if (_nonPersistentEntitiesScriptManager) {
+        QList<EntityItemID> entitiesWithEntityScripts = _nonPersistentEntitiesScriptManager->getListOfEntityScriptIDs();
 
         foreach (const EntityItemID& entityID, entitiesWithEntityScripts) {
             EntityItemPointer entityItem = getTree()->findEntityByEntityItemID(entityID);
             if (entityItem && !entityItem->getScript().isEmpty()) {
                 if (!(entityItem->isLocalEntity() || entityItem->isMyAvatarEntity())) {
-                    _nonPersistentEntitiesScriptEngine->unloadEntityScript(entityID, true);
+                    _nonPersistentEntitiesScriptManager->unloadEntityScript(entityID, true);
                 }
             }
         }
@@ -298,15 +308,15 @@ void EntityTreeRenderer::clear() {
     auto scene = _viewState->getMain3DScene();
     if (_shuttingDown) {
         // unload and stop the engines
-        if (_nonPersistentEntitiesScriptEngine) {
+        if (_nonPersistentEntitiesScriptManager) {
             // do this here (instead of in deleter) to avoid marshalling unload signals back to this thread
-            _nonPersistentEntitiesScriptEngine->unloadAllEntityScripts(true);
-            _nonPersistentEntitiesScriptEngine->stop();
+            _nonPersistentEntitiesScriptManager->unloadAllEntityScripts(true);
+            _nonPersistentEntitiesScriptManager->stop();
         }
-        if (_persistentEntitiesScriptEngine) {
+        if (_persistentEntitiesScriptManager) {
             // do this here (instead of in deleter) to avoid marshalling unload signals back to this thread
-            _persistentEntitiesScriptEngine->unloadAllEntityScripts(true);
-            _persistentEntitiesScriptEngine->stop();
+            _persistentEntitiesScriptManager->unloadAllEntityScripts(true);
+            _persistentEntitiesScriptManager->stop();
         }
 
         if (scene) {
@@ -344,16 +354,16 @@ void EntityTreeRenderer::clear() {
 }
 
 void EntityTreeRenderer::reloadEntityScripts() {
-    _persistentEntitiesScriptEngine->unloadAllEntityScripts();
-    _persistentEntitiesScriptEngine->resetModuleCache();
-    _nonPersistentEntitiesScriptEngine->unloadAllEntityScripts();
-    _nonPersistentEntitiesScriptEngine->resetModuleCache();
+    _persistentEntitiesScriptManager->unloadAllEntityScripts();
+    _persistentEntitiesScriptManager->resetModuleCache();
+    _nonPersistentEntitiesScriptManager->unloadAllEntityScripts();
+    _nonPersistentEntitiesScriptManager->resetModuleCache();
 
     for (const auto& entry : _entitiesInScene) {
         const auto& renderer = entry.second;
         const auto& entity = renderer->getEntity();
         if (entity && !entity->getScript().isEmpty()) {
-            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
             scriptEngine->loadEntityScript(entity->getEntityItemID(), resolveScriptURL(entity->getScript()), true);
         }
     }
@@ -377,11 +387,11 @@ void EntityTreeRenderer::init() {
 }
 
 void EntityTreeRenderer::shutdown() {
-    if (_persistentEntitiesScriptEngine) {
-        _persistentEntitiesScriptEngine->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
+    if (_persistentEntitiesScriptManager) {
+        _persistentEntitiesScriptManager->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
     }
-    if (_nonPersistentEntitiesScriptEngine) {
-        _nonPersistentEntitiesScriptEngine->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
+    if (_nonPersistentEntitiesScriptManager) {
+        _nonPersistentEntitiesScriptManager->disconnectNonEssentialSignals(); // disconnect all slots/signals from the script engine, except essential
     }
     _shuttingDown = true;
 
@@ -697,14 +707,14 @@ void EntityTreeRenderer::checkEnterLeaveEntities() {
             // EntityItemIDs from here. The callEntityScriptMethod() method is robust against attempting to call scripts
             // for entity IDs that no longer exist.
 
-            if (_persistentEntitiesScriptEngine && _nonPersistentEntitiesScriptEngine) {
+            if (_persistentEntitiesScriptManager && _nonPersistentEntitiesScriptManager) {
                 // for all of our previous containing entities, if they are no longer containing then send them a leave event
                 foreach(const EntityItemID& entityID, _currentEntitiesInside) {
                     if (!entitiesContainingAvatar.contains(entityID)) {
                         emit leaveEntity(entityID);
                         auto entity = getTree()->findEntityByEntityItemID(entityID);
                         if (entity) {
-                            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+                            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
                             scriptEngine->callEntityScriptMethod(entityID, "leaveEntity");
                         }
                     }
@@ -716,7 +726,7 @@ void EntityTreeRenderer::checkEnterLeaveEntities() {
                         emit enterEntity(entityID);
                         auto entity = getTree()->findEntityByEntityItemID(entityID);
                         if (entity) {
-                            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+                            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
                             scriptEngine->callEntityScriptMethod(entityID, "enterEntity");
                         }
                     }
@@ -734,8 +744,8 @@ void EntityTreeRenderer::leaveDomainAndNonOwnedEntities() {
             EntityItemPointer entityItem = getTree()->findEntityByEntityItemID(entityID);
             if (entityItem && !(entityItem->isLocalEntity() || entityItem->isMyAvatarEntity())) {
                 emit leaveEntity(entityID);
-                if (_nonPersistentEntitiesScriptEngine) {
-                    _nonPersistentEntitiesScriptEngine->callEntityScriptMethod(entityID, "leaveEntity");
+                if (_nonPersistentEntitiesScriptManager) {
+                    _nonPersistentEntitiesScriptManager->callEntityScriptMethod(entityID, "leaveEntity");
                 }
             } else {
                 currentEntitiesInsideToSave.insert(entityID);
@@ -755,7 +765,7 @@ void EntityTreeRenderer::leaveAllEntities() {
             emit leaveEntity(entityID);
             EntityItemPointer entityItem = getTree()->findEntityByEntityItemID(entityID);
             if (entityItem) {
-                auto& scriptEngine = (entityItem->isLocalEntity() || entityItem->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+                auto& scriptEngine = (entityItem->isLocalEntity() || entityItem->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
                 if (scriptEngine) {
                     scriptEngine->callEntityScriptMethod(entityID, "leaveEntity");
                 }
@@ -1055,7 +1065,7 @@ void EntityTreeRenderer::deletingEntity(const EntityItemID& entityID) {
         return;
     }
 
-    auto& scriptEngine = (itr->second->getEntity()->isLocalEntity() || itr->second->getEntity()->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+    auto& scriptEngine = (itr->second->getEntity()->isLocalEntity() || itr->second->getEntity()->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
     if (_tree && !_shuttingDown && scriptEngine && !itr->second->getEntity()->getScript().isEmpty()) {
         if (_currentEntitiesInside.contains(entityID)) {
             scriptEngine->callEntityScriptMethod(entityID, "leaveEntity");
@@ -1105,7 +1115,7 @@ void EntityTreeRenderer::checkAndCallPreload(const EntityItemID& entityID, bool
         if (!entity) {
             return;
         }
-        auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+        auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
         bool shouldLoad = entity->shouldPreloadScript() && scriptEngine;
         QString scriptUrl = entity->getScript();
         if ((shouldLoad && unloadFirst) || scriptUrl.isEmpty()) {
@@ -1226,7 +1236,7 @@ void EntityTreeRenderer::entityCollisionWithEntity(const EntityItemID& idA, cons
         if ((myNodeID == entityASimulatorID && entityAIsDynamic) || (myNodeID == entityBSimulatorID && (!entityAIsDynamic || entityASimulatorID.isNull()))) {
             playEntityCollisionSound(entityA, collision);
             emit collisionWithEntity(idA, idB, collision);
-            auto& scriptEngine = (entityA->isLocalEntity() || entityA->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+            auto& scriptEngine = (entityA->isLocalEntity() || entityA->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
             if (scriptEngine) {
                 scriptEngine->callEntityScriptMethod(idA, "collisionWithEntity", idB, collision);
             }
@@ -1238,7 +1248,7 @@ void EntityTreeRenderer::entityCollisionWithEntity(const EntityItemID& idA, cons
             Collision invertedCollision(collision);
             invertedCollision.invert();
             emit collisionWithEntity(idB, idA, invertedCollision);
-            auto& scriptEngine = (entityB->isLocalEntity() || entityB->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+            auto& scriptEngine = (entityB->isLocalEntity() || entityB->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
             if (scriptEngine) {
                 scriptEngine->callEntityScriptMethod(idB, "collisionWithEntity", idA, invertedCollision);
             }
diff --git a/libraries/entities-renderer/src/EntityTreeRenderer.h b/libraries/entities-renderer/src/EntityTreeRenderer.h
index 4bbc826d1e8..08c1ca6ba8e 100644
--- a/libraries/entities-renderer/src/EntityTreeRenderer.h
+++ b/libraries/entities-renderer/src/EntityTreeRenderer.h
@@ -13,6 +13,8 @@
 #ifndef hifi_EntityTreeRenderer_h
 #define hifi_EntityTreeRenderer_h
 
+#include <memory>
+
 #include <QtCore/QSet>
 #include <QtCore/QStack>
 #include <QtGui/QMouseEvent>
@@ -34,6 +36,10 @@ class Model;
 class ScriptEngine;
 class ZoneEntityItem;
 class EntityItem;
+class ScriptEngine;
+class ScriptManager;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
 
 namespace render { namespace entities {
     class EntityRenderer;
@@ -180,7 +186,7 @@ public slots:
 
     void resetPersistentEntitiesScriptEngine();
     void resetNonPersistentEntitiesScriptEngine();
-    void setupEntityScriptEngineSignals(const ScriptEnginePointer& scriptEngine);
+    void setupEntityScriptEngineSignals(const ScriptManagerPointer& scriptManager);
 
     void findBestZoneAndMaybeContainingEntities(QSet<EntityItemID>& entitiesContainingAvatar);
 
@@ -192,7 +198,7 @@ public slots:
     EntityItemID _currentHoverOverEntityID;
     EntityItemID _currentClickingOnEntityID;
 
-    QScriptValueList createEntityArgs(const EntityItemID& entityID);
+    ScriptValueList createEntityArgs(const EntityItemID& entityID);
     void checkEnterLeaveEntities();
     void leaveDomainAndNonOwnedEntities();
     void leaveAllEntities();
@@ -203,8 +209,8 @@ public slots:
     QSet<EntityItemID> _currentEntitiesInside;
 
     bool _wantScripts;
-    ScriptEnginePointer _nonPersistentEntitiesScriptEngine; // used for domain + non-owned avatar entities, cleared on domain switch
-    ScriptEnginePointer _persistentEntitiesScriptEngine; // used for local + owned avatar entities, persists on domain switch, cleared on reload content
+    ScriptManagerPointer _nonPersistentEntitiesScriptManager; // used for domain + non-owned avatar entities, cleared on domain switch
+    ScriptManagerPointer _persistentEntitiesScriptManager; // used for local + owned avatar entities, persists on domain switch, cleared on reload content
 
     void playEntityCollisionSound(const EntityItemPointer& entity, const Collision& collision);
 
diff --git a/libraries/script-engine/src/ModelScriptingInterface.cpp b/libraries/entities-renderer/src/ModelScriptingInterface.cpp
similarity index 85%
rename from libraries/script-engine/src/ModelScriptingInterface.cpp
rename to libraries/entities-renderer/src/ModelScriptingInterface.cpp
index 499678ff06a..5d14eba0987 100644
--- a/libraries/script-engine/src/ModelScriptingInterface.cpp
+++ b/libraries/entities-renderer/src/ModelScriptingInterface.cpp
@@ -1,6 +1,6 @@
 //
 //  ModelScriptingInterface.cpp
-//  libraries/script-engine/src
+//  libraries/entities-renderer/src
 //
 //  Created by Seth Alves on 2017-1-27.
 //  Copyright 2017 High Fidelity, Inc.
@@ -10,20 +10,26 @@
 //
 
 #include "ModelScriptingInterface.h"
-#include <QScriptEngine>
-#include <QScriptValueIterator>
-#include <QtScript/QScriptValue>
 #include <model-networking/SimpleMeshProxy.h>
-#include "ScriptEngine.h"
-#include "ScriptEngineLogging.h"
-#include "OBJWriter.h"
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptEngineLogging.h>
+#include <ScriptManager.h>
+#include <ScriptValueUtils.h>
+#include <OBJWriter.h>
+
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine();
+
+    scriptEngine->registerGlobalObject("Model", new ModelScriptingInterface(manager));
+});
 
 ModelScriptingInterface::ModelScriptingInterface(QObject* parent) : QObject(parent) {
-    _modelScriptEngine = qobject_cast<QScriptEngine*>(parent);
+    _modelScriptEngine = qobject_cast<ScriptManager*>(parent)->engine();
 
-    qScriptRegisterSequenceMetaType<QList<MeshProxy*>>(_modelScriptEngine);
-    qScriptRegisterMetaType(_modelScriptEngine, meshFaceToScriptValue, meshFaceFromScriptValue);
-    qScriptRegisterMetaType(_modelScriptEngine, qVectorMeshFaceToScriptValue, qVectorMeshFaceFromScriptValue);
+    scriptRegisterSequenceMetaType<QList<MeshProxy*>>(_modelScriptEngine.get());
+    scriptRegisterMetaType(_modelScriptEngine.get(), meshFaceToScriptValue, meshFaceFromScriptValue);
+    scriptRegisterMetaType(_modelScriptEngine.get(), qVectorMeshFaceToScriptValue, qVectorMeshFaceFromScriptValue);
 }
 
 QString ModelScriptingInterface::meshToOBJ(MeshProxyList in) {
@@ -35,7 +41,7 @@ QString ModelScriptingInterface::meshToOBJ(MeshProxyList in) {
     return writeOBJToString(meshes);
 }
 
-QScriptValue ModelScriptingInterface::appendMeshes(MeshProxyList in) {
+ScriptValue ModelScriptingInterface::appendMeshes(MeshProxyList in) {
     // figure out the size of the resulting mesh
     size_t totalVertexCount { 0 };
     size_t totalColorCount { 0 };
@@ -140,16 +146,16 @@ QScriptValue ModelScriptingInterface::appendMeshes(MeshProxyList in) {
 
 
     MeshProxy* resultProxy = new SimpleMeshProxy(result);
-    return meshToScriptValue(_modelScriptEngine, resultProxy);
+    return meshToScriptValue(_modelScriptEngine.get(), resultProxy);
 }
 
-QScriptValue ModelScriptingInterface::transformMesh(glm::mat4 transform, MeshProxy* meshProxy) {
+ScriptValue ModelScriptingInterface::transformMesh(glm::mat4 transform, MeshProxy* meshProxy) {
     if (!meshProxy) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
     MeshPointer mesh = meshProxy->getMeshPointer();
     if (!mesh) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
 
     const auto inverseTransposeTransform = glm::inverse(glm::transpose(transform));
@@ -158,45 +164,45 @@ QScriptValue ModelScriptingInterface::transformMesh(glm::mat4 transform, MeshPro
                                           [&](glm::vec3 normal){ return glm::vec3(inverseTransposeTransform * glm::vec4(normal, 0.0f)); },
                                           [&](uint32_t index){ return index; });
     MeshProxy* resultProxy = new SimpleMeshProxy(result);
-    return meshToScriptValue(_modelScriptEngine, resultProxy);
+    return meshToScriptValue(_modelScriptEngine.get(), resultProxy);
 }
 
-QScriptValue ModelScriptingInterface::getVertexCount(MeshProxy* meshProxy) {
+ScriptValue ModelScriptingInterface::getVertexCount(MeshProxy* meshProxy) {
     if (!meshProxy) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
     MeshPointer mesh = meshProxy->getMeshPointer();
     if (!mesh) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
 
     gpu::BufferView::Index numVertices = (gpu::BufferView::Index)mesh->getNumVertices();
 
-    return numVertices;
+    return _modelScriptEngine->newValue(numVertices);
 }
 
-QScriptValue ModelScriptingInterface::getVertex(MeshProxy* meshProxy, int vertexIndex) {
+ScriptValue ModelScriptingInterface::getVertex(MeshProxy* meshProxy, int vertexIndex) {
     if (!meshProxy) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
     MeshPointer mesh = meshProxy->getMeshPointer();
     if (!mesh) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
 
     const gpu::BufferView& vertexBufferView = mesh->getVertexBuffer();
     gpu::BufferView::Index numVertices = (gpu::BufferView::Index)mesh->getNumVertices();
 
     if (vertexIndex < 0 || vertexIndex >= numVertices) {
-        return QScriptValue(false);
+        return ScriptValue();
     }
 
     glm::vec3 pos = vertexBufferView.get<glm::vec3>(vertexIndex);
-    return vec3ToScriptValue(_modelScriptEngine, pos);
+    return vec3ToScriptValue(_modelScriptEngine.get(), pos);
 }
 
 
-QScriptValue ModelScriptingInterface::newMesh(const QVector<glm::vec3>& vertices,
+ScriptValue ModelScriptingInterface::newMesh(const QVector<glm::vec3>& vertices,
                                               const QVector<glm::vec3>& normals,
                                               const QVector<MeshFace>& faces) {
     graphics::MeshPointer mesh(std::make_shared<graphics::Mesh>());
@@ -247,5 +253,5 @@ QScriptValue ModelScriptingInterface::newMesh(const QVector<glm::vec3>& vertices
 
 
     MeshProxy* meshProxy = new SimpleMeshProxy(mesh);
-    return meshToScriptValue(_modelScriptEngine, meshProxy);
+    return meshToScriptValue(_modelScriptEngine.get(), meshProxy);
 }
diff --git a/libraries/script-engine/src/ModelScriptingInterface.h b/libraries/entities-renderer/src/ModelScriptingInterface.h
similarity index 84%
rename from libraries/script-engine/src/ModelScriptingInterface.h
rename to libraries/entities-renderer/src/ModelScriptingInterface.h
index 5bd8d089441..9bc5529a5ad 100644
--- a/libraries/script-engine/src/ModelScriptingInterface.h
+++ b/libraries/entities-renderer/src/ModelScriptingInterface.h
@@ -1,6 +1,6 @@
 //
 //  ModelScriptingInterface.h
-//  libraries/script-engine/src
+//  libraries/entities-renderer/src
 //
 //  Created by Seth Alves on 2017-1-27.
 //  Copyright 2017 High Fidelity, Inc.
@@ -15,10 +15,15 @@
 #ifndef hifi_ModelScriptingInterface_h
 #define hifi_ModelScriptingInterface_h
 
+#include <memory>
+
 #include <QtCore/QObject>
 
 #include <RegisteredMetaTypes.h>
-class QScriptEngine;
+#include <ScriptValue.h>
+
+class ScriptEngine;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
 
 /*@jsdoc
  * The <code>Model</code> API provides the ability to manipulate meshes. You can get the meshes for an entity using 
@@ -56,7 +61,7 @@ class ModelScriptingInterface : public QObject {
      * @param {MeshProxy[]} meshes - The meshes to combine.
      * @returns {MeshProxy} The combined mesh.
      */
-    Q_INVOKABLE QScriptValue appendMeshes(MeshProxyList in);
+    Q_INVOKABLE ScriptValue appendMeshes(MeshProxyList in);
 
     /*@jsdoc
      * Transforms the vertices in a mesh.
@@ -65,7 +70,7 @@ class ModelScriptingInterface : public QObject {
      * @param {MeshProxy} mesh - The mesh to apply the transform to.
      * @returns {MeshProxy|boolean} The transformed mesh, if valid. <code>false</code> if an error.
      */
-    Q_INVOKABLE QScriptValue transformMesh(glm::mat4 transform, MeshProxy* meshProxy);
+    Q_INVOKABLE ScriptValue transformMesh(glm::mat4 transform, MeshProxy* meshProxy);
 
     /*@jsdoc
      * Creates a new mesh.
@@ -75,7 +80,7 @@ class ModelScriptingInterface : public QObject {
      * @param {MeshFace[]} faces - The faces in the mesh.
      * @returns {MeshProxy} A new mesh.
      */
-    Q_INVOKABLE QScriptValue newMesh(const QVector<glm::vec3>& vertices,
+    Q_INVOKABLE ScriptValue newMesh(const QVector<glm::vec3>& vertices,
                                      const QVector<glm::vec3>& normals,
                                      const QVector<MeshFace>& faces);
 
@@ -85,7 +90,7 @@ class ModelScriptingInterface : public QObject {
      * @param {MeshProxy} mesh - The mesh to count the vertices in.
      * @returns {number|boolean} The number of vertices in the mesh, if valid. <code>false</code> if an error.
      */
-    Q_INVOKABLE QScriptValue getVertexCount(MeshProxy* meshProxy);
+    Q_INVOKABLE ScriptValue getVertexCount(MeshProxy* meshProxy);
 
     /*@jsdoc
      * Gets the position of a vertex in a mesh.
@@ -94,10 +99,10 @@ class ModelScriptingInterface : public QObject {
      * @param {number} index - The index of the vertex to get.
      * @returns {Vec3|boolean} The local position of the vertex relative to the mesh, if valid. <code>false</code> if an error.
      */
-    Q_INVOKABLE QScriptValue getVertex(MeshProxy* meshProxy, int vertexIndex);
+    Q_INVOKABLE ScriptValue getVertex(MeshProxy* meshProxy, int vertexIndex);
 
 private:
-    QScriptEngine* _modelScriptEngine { nullptr };
+    ScriptEnginePointer _modelScriptEngine;
 };
 
 #endif // hifi_ModelScriptingInterface_h
diff --git a/libraries/entities-renderer/src/RenderablePolyVoxEntityItem.cpp b/libraries/entities-renderer/src/RenderablePolyVoxEntityItem.cpp
index 089c6e476a6..403e72940c8 100644
--- a/libraries/entities-renderer/src/RenderablePolyVoxEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderablePolyVoxEntityItem.cpp
@@ -21,7 +21,7 @@
 #include <QtConcurrent/QtConcurrentRun>
 
 #include <model-networking/SimpleMeshProxy.h>
-#include <ModelScriptingInterface.h>
+#include "ModelScriptingInterface.h"
 #include <EntityEditPacketSender.h>
 #include <PhysicalEntitySimulation.h>
 #include <StencilMaskPass.h>
diff --git a/libraries/entities/CMakeLists.txt b/libraries/entities/CMakeLists.txt
index b6ed62c15a7..bf612b156e5 100644
--- a/libraries/entities/CMakeLists.txt
+++ b/libraries/entities/CMakeLists.txt
@@ -1,5 +1,5 @@
 set(TARGET_NAME entities)
-setup_hifi_library(Network Script)
+setup_hifi_library(Network)
 target_include_directories(${TARGET_NAME} PRIVATE "${OPENSSL_INCLUDE_DIR}")
 include_hifi_library_headers(hfm)
 include_hifi_library_headers(model-serializers)
@@ -8,7 +8,7 @@ include_hifi_library_headers(image)
 include_hifi_library_headers(ktx)
 include_hifi_library_headers(material-networking)
 include_hifi_library_headers(procedural)
-link_hifi_libraries(shared shaders networking octree avatars graphics model-networking)
+link_hifi_libraries(shared shaders networking octree avatars graphics model-networking script-engine)
 
 if (WIN32)
   add_compile_definitions(_USE_MATH_DEFINES)
diff --git a/libraries/entities/src/AmbientLightPropertyGroup.cpp b/libraries/entities/src/AmbientLightPropertyGroup.cpp
index 38017a684b1..b88e7904b1b 100644
--- a/libraries/entities/src/AmbientLightPropertyGroup.cpp
+++ b/libraries/entities/src/AmbientLightPropertyGroup.cpp
@@ -19,14 +19,14 @@
 
 const float AmbientLightPropertyGroup::DEFAULT_AMBIENT_LIGHT_INTENSITY = 0.5f;
 
-void AmbientLightPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-    QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void AmbientLightPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+    ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
     
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_AMBIENT_LIGHT_INTENSITY, AmbientLight, ambientLight, AmbientIntensity, ambientIntensity);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_AMBIENT_LIGHT_URL, AmbientLight, ambientLight, AmbientURL, ambientURL);
 }
 
-void AmbientLightPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void AmbientLightPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(ambientLight, ambientIntensity, float, setAmbientIntensity);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(ambientLight, ambientURL, QString, setAmbientURL);
     
diff --git a/libraries/entities/src/AmbientLightPropertyGroup.h b/libraries/entities/src/AmbientLightPropertyGroup.h
index 07f253d5683..4eb447cb77c 100644
--- a/libraries/entities/src/AmbientLightPropertyGroup.h
+++ b/libraries/entities/src/AmbientLightPropertyGroup.h
@@ -17,7 +17,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
 #include "EntityItemPropertiesMacros.h"
 #include "PropertyGroup.h"
 
@@ -26,6 +25,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 /*@jsdoc
  * Ambient light is defined by the following properties:
@@ -38,10 +39,10 @@ class ReadBitstreamToTreeParams;
 class AmbientLightPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const AmbientLightPropertyGroup& other);
 
diff --git a/libraries/entities/src/AnimationPropertyGroup.cpp b/libraries/entities/src/AnimationPropertyGroup.cpp
index 0666c7317fd..fd19e4e9b83 100644
--- a/libraries/entities/src/AnimationPropertyGroup.cpp
+++ b/libraries/entities/src/AnimationPropertyGroup.cpp
@@ -65,7 +65,7 @@ bool operator!=(const AnimationPropertyGroup& a, const AnimationPropertyGroup& b
  * @property {boolean} hold=false - <code>true</code> if the rotations and translations of the last frame played are 
  *     maintained when the animation stops playing, <code>false</code> if they aren't.
  */
-void AnimationPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void AnimationPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_ANIMATION_URL, Animation, animation, URL, url);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_ANIMATION_ALLOW_TRANSLATION, Animation, animation, AllowTranslation, allowTranslation);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_ANIMATION_FPS, Animation, animation, FPS, fps);
@@ -78,7 +78,7 @@ void AnimationPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desire
 }
 
 
-void AnimationPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void AnimationPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
 
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(animation, url, QString, setURL);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(animation, allowTranslation, bool, setAllowTranslation);
diff --git a/libraries/entities/src/AnimationPropertyGroup.h b/libraries/entities/src/AnimationPropertyGroup.h
index bebfe2c1946..4f316568c8a 100644
--- a/libraries/entities/src/AnimationPropertyGroup.h
+++ b/libraries/entities/src/AnimationPropertyGroup.h
@@ -17,8 +17,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
-
 #include "EntityItemPropertiesMacros.h"
 #include "PropertyGroup.h"
 
@@ -27,16 +25,18 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 class AnimationPropertyGroup : public PropertyGroup {
 public:
     static const float MAXIMUM_POSSIBLE_FRAME;
 
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const AnimationPropertyGroup& other);
 
diff --git a/libraries/entities/src/BloomPropertyGroup.cpp b/libraries/entities/src/BloomPropertyGroup.cpp
index 2c4d46ab35f..83151499257 100644
--- a/libraries/entities/src/BloomPropertyGroup.cpp
+++ b/libraries/entities/src/BloomPropertyGroup.cpp
@@ -16,13 +16,13 @@
 #include "EntityItemProperties.h"
 #include "EntityItemPropertiesMacros.h"
 
-void BloomPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void BloomPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_BLOOM_INTENSITY, Bloom, bloom, BloomIntensity, bloomIntensity);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_BLOOM_THRESHOLD, Bloom, bloom, BloomThreshold, bloomThreshold);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_BLOOM_SIZE, Bloom, bloom, BloomSize, bloomSize);
 }
 
-void BloomPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void BloomPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(bloom, bloomIntensity, float, setBloomIntensity);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(bloom, bloomThreshold, float, setBloomThreshold);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(bloom, bloomSize, float, setBloomSize);
diff --git a/libraries/entities/src/BloomPropertyGroup.h b/libraries/entities/src/BloomPropertyGroup.h
index 98711820e55..22e2fb3a9eb 100644
--- a/libraries/entities/src/BloomPropertyGroup.h
+++ b/libraries/entities/src/BloomPropertyGroup.h
@@ -15,8 +15,6 @@
 #include <stdint.h>
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
-
 #include "PropertyGroup.h"
 #include "EntityItemPropertiesMacros.h"
 
@@ -25,6 +23,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 static const float INITIAL_BLOOM_INTENSITY { 0.25f };
 static const float INITIAL_BLOOM_THRESHOLD { 0.7f };
@@ -40,10 +40,10 @@ static const float INITIAL_BLOOM_SIZE { 0.9f };
 class BloomPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const BloomPropertyGroup& other);
 
diff --git a/libraries/entities/src/EntityEditFilters.cpp b/libraries/entities/src/EntityEditFilters.cpp
index 16dace0fc8f..563f62d3802 100644
--- a/libraries/entities/src/EntityEditFilters.cpp
+++ b/libraries/entities/src/EntityEditFilters.cpp
@@ -15,6 +15,9 @@
 
 #include <ResourceManager.h>
 #include <shared/ScriptInitializerMixin.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
+#include <ScriptProgram.h>
 
 QList<EntityItemID> EntityEditFilters::getZonesByPosition(glm::vec3& position) {
     QList<EntityItemID> zones;
@@ -76,19 +79,19 @@ bool EntityEditFilters::filter(glm::vec3& position, EntityItemProperties& proper
             auto oldProperties = propertiesIn.getDesiredProperties();
             auto specifiedProperties = propertiesIn.getChangedProperties();
             propertiesIn.setDesiredProperties(specifiedProperties);
-            QScriptValue inputValues = propertiesIn.copyToScriptValue(filterData.engine, false, true, true);
+            ScriptValue inputValues = propertiesIn.copyToScriptValue(filterData.engine.get(), false, true, true);
             propertiesIn.setDesiredProperties(oldProperties);
 
             auto in = QJsonValue::fromVariant(inputValues.toVariant()); // grab json copy now, because the inputValues might be side effected by the filter.
 
-            QScriptValueList args;
+            ScriptValueList args;
             args << inputValues;
-            args << filterType;
+            args << filterData.engine->newValue(filterType);
 
             // get the current properties for then entity and include them for the filter call
             if (existingEntity && filterData.wantsOriginalProperties) {
                 auto currentProperties = existingEntity->getProperties(filterData.includedOriginalProperties);
-                QScriptValue currentValues = currentProperties.copyToScriptValue(filterData.engine, false, true, true);
+                ScriptValue currentValues = currentProperties.copyToScriptValue(filterData.engine.get(), false, true, true);
                 args << currentValues;
             }
 
@@ -98,17 +101,17 @@ bool EntityEditFilters::filter(glm::vec3& position, EntityItemProperties& proper
                 auto zoneEntity = _tree->findEntityByEntityItemID(id);
                 if (zoneEntity) {
                     auto zoneProperties = zoneEntity->getProperties(filterData.includedZoneProperties);
-                    QScriptValue zoneValues = zoneProperties.copyToScriptValue(filterData.engine, false, true, true);
+                    ScriptValue zoneValues = zoneProperties.copyToScriptValue(filterData.engine.get(), false, true, true);
 
                     if (filterData.wantsZoneBoundingBox) {
                         bool success = true;
                         AABox aaBox = zoneEntity->getAABox(success);
                         if (success) {
-                            QScriptValue boundingBox = filterData.engine->newObject();
-                            QScriptValue bottomRightNear = vec3ToScriptValue(filterData.engine, aaBox.getCorner());
-                            QScriptValue topFarLeft = vec3ToScriptValue(filterData.engine, aaBox.calcTopFarLeft());
-                            QScriptValue center = vec3ToScriptValue(filterData.engine, aaBox.calcCenter());
-                            QScriptValue boundingBoxDimensions = vec3ToScriptValue(filterData.engine, aaBox.getDimensions());
+                            ScriptValue boundingBox = filterData.engine->newObject();
+                            ScriptValue bottomRightNear = vec3ToScriptValue(filterData.engine.get(), aaBox.getCorner());
+                            ScriptValue topFarLeft = vec3ToScriptValue(filterData.engine.get(), aaBox.calcTopFarLeft());
+                            ScriptValue center = vec3ToScriptValue(filterData.engine.get(), aaBox.calcCenter());
+                            ScriptValue boundingBoxDimensions = vec3ToScriptValue(filterData.engine.get(), aaBox.getDimensions());
                             boundingBox.setProperty("brn", bottomRightNear);
                             boundingBox.setProperty("tfl", topFarLeft);
                             boundingBox.setProperty("center", center);
@@ -122,14 +125,14 @@ bool EntityEditFilters::filter(glm::vec3& position, EntityItemProperties& proper
                     // to be the fourth parameter, so we need to pad the args accordingly
                     int EXPECTED_ARGS = 3;
                     if (args.length() < EXPECTED_ARGS) {
-                        args << QScriptValue();
+                        args << ScriptValue();
                     }
                     assert(args.length() == EXPECTED_ARGS); // we MUST have 3 args by now!
                     args << zoneValues;
                 }
             }
 
-            QScriptValue result = filterData.filterFn.call(_nullObjectForFilter, args);
+            ScriptValue result = filterData.filterFn.call(_nullObjectForFilter, args);
 
             if (filterData.uncaughtExceptions()) {
                 return false;
@@ -166,10 +169,6 @@ bool EntityEditFilters::filter(glm::vec3& position, EntityItemProperties& proper
 
 void EntityEditFilters::removeFilter(EntityItemID entityID) {
     QWriteLocker writeLock(&_lock);
-    FilterData filterData = _filterDataMap.value(entityID);
-    if (filterData.valid()) {
-        delete filterData.engine;
-    }
     _filterDataMap.remove(entityID);
 }
 
@@ -216,20 +215,20 @@ void EntityEditFilters::addFilter(EntityItemID entityID, QString filterURL) {
 }
 
 // Copied from ScriptEngine.cpp. We should make this a class method for reuse.
-// Note: I've deliberately stopped short of using ScriptEngine instead of QScriptEngine, as that is out of project scope at this point.
-static bool hasCorrectSyntax(const QScriptProgram& program) {
-    const auto syntaxCheck = QScriptEngine::checkSyntax(program.sourceCode());
-    if (syntaxCheck.state() != QScriptSyntaxCheckResult::Valid) {
-        const auto error = syntaxCheck.errorMessage();
-        const auto line = QString::number(syntaxCheck.errorLineNumber());
-        const auto column = QString::number(syntaxCheck.errorColumnNumber());
-        const auto message = QString("[SyntaxError] %1 in %2:%3(%4)").arg(error, program.fileName(), line, column);
+// Note: I've deliberately stopped short of using ScriptEngine instead of ScriptEngine, as that is out of project scope at this point.
+static bool hasCorrectSyntax(const ScriptProgramPointer& program) {
+    const auto syntaxCheck = program->checkSyntax();
+    if (syntaxCheck->state() != ScriptSyntaxCheckResult::Valid) {
+        const auto error = syntaxCheck->errorMessage();
+        const auto line = QString::number(syntaxCheck->errorLineNumber());
+        const auto column = QString::number(syntaxCheck->errorColumnNumber());
+        const auto message = QString("[SyntaxError] %1 in %2:%3(%4)").arg(error, program->fileName(), line, column);
         qCritical() << qPrintable(message);
         return false;
     }
     return true;
 }
-static bool hadUncaughtExceptions(QScriptEngine& engine, const QString& fileName) {
+static bool hadUncaughtExceptions(ScriptEngine& engine, const QString& fileName) {
     if (engine.hasUncaughtException()) {
         const auto backtrace = engine.uncaughtExceptionBacktrace();
         const auto exception = engine.uncaughtException().toString();
@@ -255,16 +254,17 @@ void EntityEditFilters::scriptRequestFinished(EntityItemID entityID) {
         const QString urlString = scriptRequest->getUrl().toString();
         auto scriptContents = scriptRequest->getData();
         qInfo() << "Downloaded script:" << scriptContents;
-        QScriptProgram program(scriptContents, urlString);
+        // create a ScriptEngine for this script
+        ScriptManagerPointer manager = newScriptManager(ScriptManager::ENTITY_SERVER_SCRIPT, "", urlString);
+        ScriptEnginePointer engine = manager->engine();
+        ScriptProgramPointer program = engine->newProgram(scriptContents, urlString);
         if (hasCorrectSyntax(program)) {
-            // create a QScriptEngine for this script
-            QScriptEngine* engine = new QScriptEngine();
             engine->setObjectName("filter:" + entityID.toString());
             engine->setProperty("type", "edit_filter");
             engine->setProperty("fileName", urlString);
             engine->setProperty("entityID", entityID);
-            engine->globalObject().setProperty("Script", engine->newQObject(engine));
-            DependencyManager::get<ScriptInitializers>()->runScriptInitializers(engine);
+            engine->globalObject().setProperty("Script", engine->newQObject(manager.get()));
+            DependencyManager::get<ScriptInitializers>()->runScriptInitializers(engine.get());
             engine->evaluate(scriptContents, urlString);
             if (!hadUncaughtExceptions(*engine, urlString)) {
                 // put the engine in the engine map (so we don't leak them, etc...)
@@ -273,7 +273,7 @@ void EntityEditFilters::scriptRequestFinished(EntityItemID entityID) {
                 filterData.rejectAll = false;
                 
                 // define the uncaughtException function
-                QScriptEngine& engineRef = *engine;
+                ScriptEngine& engineRef = *engine;
                 filterData.uncaughtExceptions = [&engineRef, urlString]() { return hadUncaughtExceptions(engineRef, urlString); };
 
                 // now get the filter function
@@ -287,28 +287,28 @@ void EntityEditFilters::scriptRequestFinished(EntityItemID entityID) {
                 filterData.filterFn = global.property("filter");
                 if (!filterData.filterFn.isFunction()) {
                     qDebug() << "Filter function specified but not found. Will reject all edits for those without lock rights.";
-                    delete engine;
+                    engine.reset();
                     filterData.rejectAll=true;
                 }
 
                 // if the wantsToFilterEdit is a boolean evaluate as a boolean, otherwise assume true
-                QScriptValue wantsToFilterAddValue = filterData.filterFn.property("wantsToFilterAdd");
+                ScriptValue wantsToFilterAddValue = filterData.filterFn.property("wantsToFilterAdd");
                 filterData.wantsToFilterAdd = wantsToFilterAddValue.isBool() ? wantsToFilterAddValue.toBool() : true;
 
                 // if the wantsToFilterEdit is a boolean evaluate as a boolean, otherwise assume true
-                QScriptValue wantsToFilterEditValue = filterData.filterFn.property("wantsToFilterEdit");
+                ScriptValue wantsToFilterEditValue = filterData.filterFn.property("wantsToFilterEdit");
                 filterData.wantsToFilterEdit = wantsToFilterEditValue.isBool() ? wantsToFilterEditValue.toBool() : true;
 
                 // if the wantsToFilterPhysics is a boolean evaluate as a boolean, otherwise assume true
-                QScriptValue wantsToFilterPhysicsValue = filterData.filterFn.property("wantsToFilterPhysics");
+                ScriptValue wantsToFilterPhysicsValue = filterData.filterFn.property("wantsToFilterPhysics");
                 filterData.wantsToFilterPhysics = wantsToFilterPhysicsValue.isBool() ? wantsToFilterPhysicsValue.toBool() : true;
 
                 // if the wantsToFilterDelete is a boolean evaluate as a boolean, otherwise assume false
-                QScriptValue wantsToFilterDeleteValue = filterData.filterFn.property("wantsToFilterDelete");
+                ScriptValue wantsToFilterDeleteValue = filterData.filterFn.property("wantsToFilterDelete");
                 filterData.wantsToFilterDelete = wantsToFilterDeleteValue.isBool() ? wantsToFilterDeleteValue.toBool() : false;
 
                 // check to see if the filterFn has properties asking for Original props
-                QScriptValue wantsOriginalPropertiesValue = filterData.filterFn.property("wantsOriginalProperties");
+                ScriptValue wantsOriginalPropertiesValue = filterData.filterFn.property("wantsOriginalProperties");
                 // if the wantsOriginalProperties is a boolean, or a string, or list of strings, then evaluate as follows:
                 //   - boolean - true  - include all original properties
                 //               false - no properties at all
@@ -329,7 +329,7 @@ void EntityEditFilters::scriptRequestFinished(EntityItemID entityID) {
                 }
 
                 // check to see if the filterFn has properties asking for Zone props
-                QScriptValue wantsZonePropertiesValue = filterData.filterFn.property("wantsZoneProperties");
+                ScriptValue wantsZonePropertiesValue = filterData.filterFn.property("wantsZoneProperties");
                 // if the wantsZoneProperties is a boolean, or a string, or list of strings, then evaluate as follows:
                 //   - boolean - true  - include all Zone properties
                 //               false - no properties at all
diff --git a/libraries/entities/src/EntityEditFilters.h b/libraries/entities/src/EntityEditFilters.h
index 69fd9209981..cc44ff47fbe 100644
--- a/libraries/entities/src/EntityEditFilters.h
+++ b/libraries/entities/src/EntityEditFilters.h
@@ -13,21 +13,23 @@
 
 #include <QObject>
 #include <QMap>
-#include <QScriptValue>
-#include <QScriptEngine>
 #include <glm/glm.hpp>
 
 #include <functional>
 
+#include <ScriptValue.h>
+
 #include "EntityItemID.h"
 #include "EntityItemProperties.h"
 #include "EntityTree.h"
 
+class ScriptEngine;
+
 class EntityEditFilters : public QObject, public Dependency {
     Q_OBJECT
 public:
     struct FilterData {
-        QScriptValue filterFn;
+        ScriptValue filterFn;
         bool wantsOriginalProperties { false };
         bool wantsZoneProperties { false };
 
@@ -41,10 +43,10 @@ class EntityEditFilters : public QObject, public Dependency {
         bool wantsZoneBoundingBox { false };
 
         std::function<bool()> uncaughtExceptions;
-        QScriptEngine* engine;
+        ScriptEnginePointer engine;
         bool rejectAll;
         
-        FilterData(): engine(nullptr), rejectAll(false) {};
+        FilterData(): rejectAll(false) {};
         bool valid() { return (rejectAll || (engine != nullptr && filterFn.isFunction() && uncaughtExceptions)); }
     };
 
@@ -68,7 +70,7 @@ private slots:
 
     EntityTreePointer _tree {};
     bool _rejectAll {false};
-    QScriptValue _nullObjectForFilter{};
+    ScriptValue _nullObjectForFilter{};
     
     QReadWriteLock _lock;
     QMap<EntityItemID, FilterData> _filterDataMap;
diff --git a/libraries/entities/src/EntityItemID.cpp b/libraries/entities/src/EntityItemID.cpp
deleted file mode 100644
index 28b8e109ca1..00000000000
--- a/libraries/entities/src/EntityItemID.cpp
+++ /dev/null
@@ -1,72 +0,0 @@
-//
-//  EntityItemID.cpp
-//  libraries/entities/src
-//
-//  Created by Brad Hefta-Gaub on 12/4/13.
-//  Copyright 2013 High Fidelity, Inc.
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#include "EntityItemID.h"
-#include <QtCore/QObject>
-#include <QDebug>
-
-#include <BufferParser.h>
-#include <udt/PacketHeaders.h>
-#include <UUID.h>
-
-#include "RegisteredMetaTypes.h"
-
-int entityItemIDTypeID = qRegisterMetaType<EntityItemID>();
-
-EntityItemID::EntityItemID() : QUuid()
-{
-}
-
-
-EntityItemID::EntityItemID(const QUuid& id) : QUuid(id)
-{
-}
-
-// EntityItemID::EntityItemID(const EntityItemID& other) : QUuid(other)
-// {
-// }
-
-EntityItemID EntityItemID::readEntityItemIDFromBuffer(const unsigned char* data, int bytesLeftToRead) {
-    EntityItemID result;
-    if (bytesLeftToRead >= NUM_BYTES_RFC4122_UUID) {
-        BufferParser(data, bytesLeftToRead).readUuid(result);
-    }
-    return result;
-}
-
-QScriptValue EntityItemID::toScriptValue(QScriptEngine* engine) const { 
-    return EntityItemIDtoScriptValue(engine, *this); 
-}
-
-QScriptValue EntityItemIDtoScriptValue(QScriptEngine* engine, const EntityItemID& id) {
-    return quuidToScriptValue(engine, id);
-}
-
-void EntityItemIDfromScriptValue(const QScriptValue &object, EntityItemID& id) {
-    quuidFromScriptValue(object, id);
-}
-
-QVector<EntityItemID> qVectorEntityItemIDFromScriptValue(const QScriptValue& array) {
-    if (!array.isArray()) {
-        return QVector<EntityItemID>();
-    }
-    QVector<EntityItemID> newVector;
-    int length = array.property("length").toInteger();
-    newVector.reserve(length);
-    for (int i = 0; i < length; i++) {
-        QString uuidAsString = array.property(i).toString();
-        EntityItemID fromString(uuidAsString);
-        newVector << fromString;
-    }
-    return newVector;
-}
-
-size_t std::hash<EntityItemID>::operator()(const EntityItemID& id) const { return qHash(id); }
diff --git a/libraries/entities/src/EntityItemProperties.cpp b/libraries/entities/src/EntityItemProperties.cpp
index 8df85bcfe62..fcafd75ea9e 100644
--- a/libraries/entities/src/EntityItemProperties.cpp
+++ b/libraries/entities/src/EntityItemProperties.cpp
@@ -30,6 +30,7 @@
 #include <RegisteredMetaTypes.h>
 #include <Extents.h>
 #include <VariantMapToScriptValue.h>
+#include <ScriptValue.h>
 
 #include "EntitiesLogging.h"
 #include "EntityItem.h"
@@ -1571,14 +1572,14 @@ EntityPropertyFlags EntityItemProperties::getChangedProperties() const {
  * @property {Entities.RingGizmo} ring - The ring gizmo properties.
  */
 
-QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool skipDefaults, bool allowUnknownCreateTime,
+ScriptValue EntityItemProperties::copyToScriptValue(ScriptEngine* engine, bool skipDefaults, bool allowUnknownCreateTime,
     bool strictSemantics, EntityPsuedoPropertyFlags psueudoPropertyFlags) const {
 
     // If strictSemantics is true and skipDefaults is false, then all and only those properties are copied for which the property flag
     // is included in _desiredProperties, or is one of the specially enumerated ALWAYS properties below.
     // (There may be exceptions, but if so, they are bugs.)
     // In all other cases, you are welcome to inspect the code and try to figure out what was intended. I wish you luck. -HRS 1/18/17
-    QScriptValue properties = engine->newObject();
+    ScriptValue properties = engine->newObject();
     EntityItemProperties defaultEntityProperties;
 
     const bool psuedoPropertyFlagsActive = psueudoPropertyFlags.test(EntityPsuedoPropertyFlag::FlagsActive);
@@ -1922,7 +1923,7 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
         // Handle conversions to old 'textures' property from "imageURL"
         if (((!psuedoPropertyFlagsButDesiredEmpty && _desiredProperties.isEmpty()) || _desiredProperties.getHasProperty(PROP_IMAGE_URL)) &&
                 (!skipDefaults || defaultEntityProperties._imageURL != _imageURL)) {
-            QScriptValue textures = engine->newObject();
+            ScriptValue textures = engine->newObject();
             textures.setProperty("tex.picture", _imageURL);
             properties.setProperty("textures", textures);
         }
@@ -1957,11 +1958,11 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
         (!psuedoPropertyFlagsActive || psueudoPropertyFlags.test(EntityPsuedoPropertyFlag::BoundingBox))) {
 
         AABox aaBox = getAABox();
-        QScriptValue boundingBox = engine->newObject();
-        QScriptValue bottomRightNear = vec3ToScriptValue(engine, aaBox.getCorner());
-        QScriptValue topFarLeft = vec3ToScriptValue(engine, aaBox.calcTopFarLeft());
-        QScriptValue center = vec3ToScriptValue(engine, aaBox.calcCenter());
-        QScriptValue boundingBoxDimensions = vec3ToScriptValue(engine, aaBox.getDimensions());
+        ScriptValue boundingBox = engine->newObject();
+        ScriptValue bottomRightNear = vec3ToScriptValue(engine, aaBox.getCorner());
+        ScriptValue topFarLeft = vec3ToScriptValue(engine, aaBox.calcTopFarLeft());
+        ScriptValue center = vec3ToScriptValue(engine, aaBox.calcCenter());
+        ScriptValue boundingBoxDimensions = vec3ToScriptValue(engine, aaBox.getDimensions());
         boundingBox.setProperty("brn", bottomRightNear);
         boundingBox.setProperty("tfl", topFarLeft);
         boundingBox.setProperty("center", center);
@@ -1978,7 +1979,7 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
     if (!skipDefaults && !strictSemantics &&
         (!psuedoPropertyFlagsActive || psueudoPropertyFlags.test(EntityPsuedoPropertyFlag::RenderInfo))) {
 
-        QScriptValue renderInfo = engine->newObject();
+        ScriptValue renderInfo = engine->newObject();
 
         /*@jsdoc
          * Information on how an entity is rendered. Properties are only filled in for <code>Model</code> entities; other
@@ -2023,8 +2024,8 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
     return properties;
 }
 
-void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool honorReadOnly) {
-    QScriptValue typeScriptValue = object.property("type");
+void EntityItemProperties::copyFromScriptValue(const ScriptValue& object, bool honorReadOnly) {
+    ScriptValue typeScriptValue = object.property("type");
     if (typeScriptValue.isValid()) {
         setType(typeScriptValue.toVariant().toString());
     }
@@ -2279,7 +2280,7 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
 
     // Handle conversions from old 'textures' property to "imageURL"
     {
-        QScriptValue V = object.property("textures");
+        ScriptValue V = object.property("textures");
         if (_type == EntityTypes::Image && V.isValid() && !object.property("imageURL").isValid()) {
             bool isValid = false;
             QString textures = QString_convertFromScriptValue(V, isValid);
@@ -2298,7 +2299,7 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
 
     // Handle old "faceCamera" and "isFacingAvatar" props
     if (_type != EntityTypes::PolyLine) {
-        QScriptValue P = object.property("faceCamera");
+        ScriptValue P = object.property("faceCamera");
         if (P.isValid() && !object.property("billboardMode").isValid()) {
             bool newValue = P.toVariant().toBool();
             bool oldValue = getBillboardMode() == BillboardMode::YAW;
@@ -2308,7 +2309,7 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
         }
     }
     {
-        QScriptValue P = object.property("isFacingAvatar");
+        ScriptValue P = object.property("isFacingAvatar");
         if (P.isValid() && !object.property("billboardMode").isValid() && !object.property("faceCamera").isValid()) {
             bool newValue = P.toVariant().toBool();
             bool oldValue = getBillboardMode() == BillboardMode::FULL;
@@ -2321,13 +2322,13 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
     _lastEdited = usecTimestampNow();
 }
 
-void EntityItemProperties::copyFromJSONString(QScriptEngine& scriptEngine, const QString& jsonString) {
+void EntityItemProperties::copyFromJSONString(ScriptEngine& scriptEngine, const QString& jsonString) {
     // DANGER: this method is expensive
     QJsonDocument propertiesDoc = QJsonDocument::fromJson(jsonString.toUtf8());
     QJsonObject propertiesObj = propertiesDoc.object();
     QVariant propertiesVariant(propertiesObj);
     QVariantMap propertiesMap = propertiesVariant.toMap();
-    QScriptValue propertiesScriptValue = variantMapToScriptValue(propertiesMap, scriptEngine);
+    ScriptValue propertiesScriptValue = variantMapToScriptValue(propertiesMap, scriptEngine);
     bool honorReadOnly = true;
     copyFromScriptValue(propertiesScriptValue, honorReadOnly);
 }
@@ -2575,37 +2576,39 @@ void EntityItemProperties::merge(const EntityItemProperties& other) {
     _lastEdited = usecTimestampNow();
 }
 
-QScriptValue EntityItemPropertiesToScriptValue(QScriptEngine* engine, const EntityItemProperties& properties) {
+ScriptValue EntityItemPropertiesToScriptValue(ScriptEngine* engine, const EntityItemProperties& properties) {
     return properties.copyToScriptValue(engine, false);
 }
 
-QScriptValue EntityItemNonDefaultPropertiesToScriptValue(QScriptEngine* engine, const EntityItemProperties& properties) {
+ScriptValue EntityItemNonDefaultPropertiesToScriptValue(ScriptEngine* engine, const EntityItemProperties& properties) {
     return properties.copyToScriptValue(engine, true);
 }
 
-void EntityItemPropertiesFromScriptValueIgnoreReadOnly(const QScriptValue &object, EntityItemProperties& properties) {
+bool EntityItemPropertiesFromScriptValueIgnoreReadOnly(const ScriptValue &object, EntityItemProperties& properties) {
     properties.copyFromScriptValue(object, false);
+    return true;
 }
 
-void EntityItemPropertiesFromScriptValueHonorReadOnly(const QScriptValue &object, EntityItemProperties& properties) {
+bool EntityItemPropertiesFromScriptValueHonorReadOnly(const ScriptValue &object, EntityItemProperties& properties) {
     properties.copyFromScriptValue(object, true);
+    return true;
 }
 
-QScriptValue EntityPropertyFlagsToScriptValue(QScriptEngine* engine, const EntityPropertyFlags& flags) {
+ScriptValue EntityPropertyFlagsToScriptValue(ScriptEngine* engine, const EntityPropertyFlags& flags) {
     return EntityItemProperties::entityPropertyFlagsToScriptValue(engine, flags);
 }
 
-void EntityPropertyFlagsFromScriptValue(const QScriptValue& object, EntityPropertyFlags& flags) {
-    EntityItemProperties::entityPropertyFlagsFromScriptValue(object, flags);
+bool EntityPropertyFlagsFromScriptValue(const ScriptValue& object, EntityPropertyFlags& flags) {
+    return EntityItemProperties::entityPropertyFlagsFromScriptValue(object, flags);
 }
 
 
-QScriptValue EntityItemProperties::entityPropertyFlagsToScriptValue(QScriptEngine* engine, const EntityPropertyFlags& flags) {
-    QScriptValue result = engine->newObject();
+ScriptValue EntityItemProperties::entityPropertyFlagsToScriptValue(ScriptEngine* engine, const EntityPropertyFlags& flags) {
+    ScriptValue result = engine->newObject();
     return result;
 }
 
-void EntityItemProperties::entityPropertyFlagsFromScriptValue(const QScriptValue& object, EntityPropertyFlags& flags) {
+bool EntityItemProperties::entityPropertyFlagsFromScriptValue(const ScriptValue& object, EntityPropertyFlags& flags) {
     if (object.isString()) {
         EntityPropertyInfo propertyInfo;
         if (getPropertyInfo(object.toString(), propertyInfo)) {
@@ -2622,6 +2625,7 @@ void EntityItemProperties::entityPropertyFlagsFromScriptValue(const QScriptValue
             }
         }
     }
+    return true;
 }
 
 static QHash<QString, EntityPropertyInfo> _propertyInfos;
@@ -3014,18 +3018,19 @@ bool EntityItemProperties::getPropertyInfo(const QString& propertyName, EntityPr
  * @property {string} minimum - The minimum numerical value the property may have, if available, otherwise <code>""</code>.
  * @property {string} maximum - The maximum numerical value the property may have, if available, otherwise <code>""</code>.
  */
-QScriptValue EntityPropertyInfoToScriptValue(QScriptEngine* engine, const EntityPropertyInfo& propertyInfo) {
-    QScriptValue obj = engine->newObject();
+ScriptValue EntityPropertyInfoToScriptValue(ScriptEngine* engine, const EntityPropertyInfo& propertyInfo) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("propertyEnum", propertyInfo.propertyEnum);
     obj.setProperty("minimum", propertyInfo.minimum.toString());
     obj.setProperty("maximum", propertyInfo.maximum.toString());
     return obj;
 }
 
-void EntityPropertyInfoFromScriptValue(const QScriptValue& object, EntityPropertyInfo& propertyInfo) {
+bool EntityPropertyInfoFromScriptValue(const ScriptValue& object, EntityPropertyInfo& propertyInfo) {
     propertyInfo.propertyEnum = (EntityPropertyList)object.property("propertyEnum").toVariant().toUInt();
     propertyInfo.minimum = object.property("minimum").toVariant();
     propertyInfo.maximum = object.property("maximum").toVariant();
+    return true;
 }
 
 // TODO: Implement support for edit packets that can span an MTU sized buffer. We need to implement a mechanism for the
@@ -5199,7 +5204,7 @@ void EntityItemProperties::convertToCloneProperties(const EntityItemID& entityID
     setCloneAvatarEntity(ENTITY_ITEM_DEFAULT_CLONE_AVATAR_ENTITY);
 }
 
-bool EntityItemProperties::blobToProperties(QScriptEngine& scriptEngine, const QByteArray& blob, EntityItemProperties& properties) {
+bool EntityItemProperties::blobToProperties(ScriptEngine& scriptEngine, const QByteArray& blob, EntityItemProperties& properties) {
     // DANGER: this method is NOT efficient.
     // begin recipe for converting unfortunately-formatted-binary-blob to EntityItemProperties
     QJsonDocument jsonProperties = QJsonDocument::fromBinaryData(blob);
@@ -5209,17 +5214,17 @@ bool EntityItemProperties::blobToProperties(QScriptEngine& scriptEngine, const Q
     }
     QVariant variant = jsonProperties.toVariant();
     QVariantMap variantMap = variant.toMap();
-    QScriptValue scriptValue = variantMapToScriptValue(variantMap, scriptEngine);
+    ScriptValue scriptValue = variantMapToScriptValue(variantMap, scriptEngine);
     EntityItemPropertiesFromScriptValueIgnoreReadOnly(scriptValue, properties);
     // end recipe
     return true;
 }
 
-void EntityItemProperties::propertiesToBlob(QScriptEngine& scriptEngine, const QUuid& myAvatarID,
+void EntityItemProperties::propertiesToBlob(ScriptEngine& scriptEngine, const QUuid& myAvatarID,
             const EntityItemProperties& properties, QByteArray& blob, bool allProperties) {
     // DANGER: this method is NOT efficient.
     // begin recipe for extracting unfortunately-formatted-binary-blob from EntityItem
-    QScriptValue scriptValue = allProperties
+    ScriptValue scriptValue = allProperties
         ? EntityItemPropertiesToScriptValue(&scriptEngine, properties)
         : EntityItemNonDefaultPropertiesToScriptValue(&scriptEngine, properties);
     QVariant variantProperties = scriptValue.toVariant();
diff --git a/libraries/entities/src/EntityItemProperties.h b/libraries/entities/src/EntityItemProperties.h
index 91de5400627..678bd9680a5 100644
--- a/libraries/entities/src/EntityItemProperties.h
+++ b/libraries/entities/src/EntityItemProperties.h
@@ -21,7 +21,6 @@
 #include <glm/glm.hpp>
 #include <glm/gtx/component_wise.hpp>
 
-#include <QtScript/QScriptEngine>
 #include <QtCore/QObject>
 #include <QVector>
 #include <QString>
@@ -34,8 +33,9 @@
 #include <ShapeInfo.h>
 #include <ColorUtils.h>
 #include "FontFamilies.h"
+#include <ScriptValue.h>
 
-#include "EntityItemID.h"
+#include <EntityItemID.h>
 #include "EntityItemPropertiesDefaults.h"
 #include "EntityItemPropertiesMacros.h"
 #include "EntityTypes.h"
@@ -69,6 +69,8 @@
 #include "TextEffect.h"
 #include "TextAlignment.h"
 
+class ScriptEngine;
+
 const quint64 UNKNOWN_CREATED_TIME = 0;
 
 using vec3Color = glm::vec3;
@@ -96,7 +98,7 @@ EntityPropertyInfo makePropertyInfo(EntityPropertyList p, typename std::enable_i
 }
 
 /// A collection of properties of an entity item used in the scripting API. Translates between the actual properties of an
-/// entity and a JavaScript style hash/QScriptValue storing a set of properties. Used in scripting to set/get the complete
+/// entity and a JavaScript style hash/ScriptValue storing a set of properties. Used in scripting to set/get the complete
 /// set of entity item properties via JavaScript hashes/QScriptValues
 /// all units for SI units (meter, second, radian, etc) 
 class EntityItemProperties {
@@ -119,8 +121,8 @@ class EntityItemProperties {
     friend class ZoneEntityItem;
     friend class MaterialEntityItem;
 public:
-    static bool blobToProperties(QScriptEngine& scriptEngine, const QByteArray& blob, EntityItemProperties& properties);
-    static void propertiesToBlob(QScriptEngine& scriptEngine, const QUuid& myAvatarID, const EntityItemProperties& properties, 
+    static bool blobToProperties(ScriptEngine& scriptEngine, const QByteArray& blob, EntityItemProperties& properties);
+    static void propertiesToBlob(ScriptEngine& scriptEngine, const QUuid& myAvatarID, const EntityItemProperties& properties, 
         QByteArray& blob, bool allProperties = false);
 
     EntityItemProperties(EntityPropertyFlags desiredProperties = EntityPropertyFlags());
@@ -133,13 +135,13 @@ class EntityItemProperties {
     EntityTypes::EntityType getType() const { return _type; }
     void setType(EntityTypes::EntityType type) { _type = type; }
 
-    virtual QScriptValue copyToScriptValue(QScriptEngine* engine, bool skipDefaults, bool allowUnknownCreateTime = false,
+    virtual ScriptValue copyToScriptValue(ScriptEngine* engine, bool skipDefaults, bool allowUnknownCreateTime = false,
         bool strictSemantics = false, EntityPsuedoPropertyFlags psueudoPropertyFlags = EntityPsuedoPropertyFlags()) const;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool honorReadOnly);
-    void copyFromJSONString(QScriptEngine& scriptEngine, const QString& jsonString);
+    virtual void copyFromScriptValue(const ScriptValue& object, bool honorReadOnly);
+    void copyFromJSONString(ScriptEngine& scriptEngine, const QString& jsonString);
 
-    static QScriptValue entityPropertyFlagsToScriptValue(QScriptEngine* engine, const EntityPropertyFlags& flags);
-    static void entityPropertyFlagsFromScriptValue(const QScriptValue& object, EntityPropertyFlags& flags);
+    static ScriptValue entityPropertyFlagsToScriptValue(ScriptEngine* engine, const EntityPropertyFlags& flags);
+    static bool entityPropertyFlagsFromScriptValue(const ScriptValue& object, EntityPropertyFlags& flags);
 
     static bool getPropertyInfo(const QString& propertyName, EntityPropertyInfo& propertyInfo);
 
@@ -539,18 +541,18 @@ class EntityItemProperties {
 };
 
 Q_DECLARE_METATYPE(EntityItemProperties);
-QScriptValue EntityItemPropertiesToScriptValue(QScriptEngine* engine, const EntityItemProperties& properties);
-QScriptValue EntityItemNonDefaultPropertiesToScriptValue(QScriptEngine* engine, const EntityItemProperties& properties);
-void EntityItemPropertiesFromScriptValueIgnoreReadOnly(const QScriptValue& object, EntityItemProperties& properties);
-void EntityItemPropertiesFromScriptValueHonorReadOnly(const QScriptValue& object, EntityItemProperties& properties);
+ScriptValue EntityItemPropertiesToScriptValue(ScriptEngine* engine, const EntityItemProperties& properties);
+ScriptValue EntityItemNonDefaultPropertiesToScriptValue(ScriptEngine* engine, const EntityItemProperties& properties);
+bool EntityItemPropertiesFromScriptValueIgnoreReadOnly(const ScriptValue& object, EntityItemProperties& properties);
+bool EntityItemPropertiesFromScriptValueHonorReadOnly(const ScriptValue& object, EntityItemProperties& properties);
 
 Q_DECLARE_METATYPE(EntityPropertyFlags);
-QScriptValue EntityPropertyFlagsToScriptValue(QScriptEngine* engine, const EntityPropertyFlags& flags);
-void EntityPropertyFlagsFromScriptValue(const QScriptValue& object, EntityPropertyFlags& flags);
+ScriptValue EntityPropertyFlagsToScriptValue(ScriptEngine* engine, const EntityPropertyFlags& flags);
+bool EntityPropertyFlagsFromScriptValue(const ScriptValue& object, EntityPropertyFlags& flags);
 
 Q_DECLARE_METATYPE(EntityPropertyInfo);
-QScriptValue EntityPropertyInfoToScriptValue(QScriptEngine* engine, const EntityPropertyInfo& propertyInfo);
-void EntityPropertyInfoFromScriptValue(const QScriptValue& object, EntityPropertyInfo& propertyInfo);
+ScriptValue EntityPropertyInfoToScriptValue(ScriptEngine* engine, const EntityPropertyInfo& propertyInfo);
+bool EntityPropertyInfoFromScriptValue(const ScriptValue& object, EntityPropertyInfo& propertyInfo);
 
 // define these inline here so the macros work
 inline void EntityItemProperties::setPosition(const glm::vec3& value)
diff --git a/libraries/entities/src/EntityItemPropertiesMacros.h b/libraries/entities/src/EntityItemPropertiesMacros.h
index c25eb21e6c5..7f08d5b03c9 100644
--- a/libraries/entities/src/EntityItemPropertiesMacros.h
+++ b/libraries/entities/src/EntityItemPropertiesMacros.h
@@ -13,8 +13,11 @@
 #ifndef hifi_EntityItemPropertiesMacros_h
 #define hifi_EntityItemPropertiesMacros_h
 
-#include "EntityItemID.h"
+#include <EntityItemID.h>
 #include <RegisteredMetaTypes.h>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
+#include <ScriptValueUtils.h>
 
 #define APPEND_ENTITY_PROPERTY(P,V) \
         if (requestedProperties.getHasProperty(P)) {                \
@@ -99,47 +102,47 @@
         changedProperties += P;    \
     }
 
-inline QScriptValue convertScriptValue(QScriptEngine* e, const glm::vec2& v) { return vec2ToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const glm::vec3& v) { return vec3ToScriptValue(e, v); }
-inline QScriptValue vec3Color_convertScriptValue(QScriptEngine* e, const glm::vec3& v) { return vec3ColorToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const glm::u8vec3& v) { return u8vec3ToScriptValue(e, v); }
-inline QScriptValue u8vec3Color_convertScriptValue(QScriptEngine* e, const glm::u8vec3& v) { return u8vec3ColorToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, float v) { return QScriptValue(v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, int v) { return QScriptValue(v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, bool v) { return QScriptValue(v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, quint16 v) { return QScriptValue(v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, quint32 v) { return QScriptValue(v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, quint64 v) { return QScriptValue((qsreal)v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QString& v) { return QScriptValue(v); }
-
-inline QScriptValue convertScriptValue(QScriptEngine* e, const glm::quat& v) { return quatToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QScriptValue& v) { return v; }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QVector<glm::vec3>& v) {return qVectorVec3ToScriptValue(e, v); }
-inline QScriptValue qVectorVec3Color_convertScriptValue(QScriptEngine* e, const QVector<glm::vec3>& v) {return qVectorVec3ColorToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QVector<glm::quat>& v) {return qVectorQuatToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QVector<bool>& v) {return qVectorBoolToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QVector<float>& v) { return qVectorFloatToScriptValue(e, v); }
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QVector<QUuid>& v) { return qVectorQUuidToScriptValue(e, v); }
-
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QRect& v) { return qRectToScriptValue(e, v); }
-
-inline QScriptValue convertScriptValue(QScriptEngine* e, const QByteArray& v) {
+inline ScriptValue convertScriptValue(ScriptEngine* e, const glm::vec2& v) { return vec2ToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const glm::vec3& v) { return vec3ToScriptValue(e, v); }
+inline ScriptValue vec3Color_convertScriptValue(ScriptEngine* e, const glm::vec3& v) { return vec3ColorToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const glm::u8vec3& v) { return u8vec3ToScriptValue(e, v); }
+inline ScriptValue u8vec3Color_convertScriptValue(ScriptEngine* e, const glm::u8vec3& v) { return u8vec3ColorToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, float v) { return e->newValue(v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, int v) { return e->newValue(v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, bool v) { return e->newValue(v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, quint16 v) { return e->newValue(v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, quint32 v) { return e->newValue(v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, quint64 v) { return e->newValue((double)v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QString& v) { return e->newValue(v); }
+
+inline ScriptValue convertScriptValue(ScriptEngine* e, const glm::quat& v) { return quatToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const ScriptValue& v) { return v; }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QVector<glm::vec3>& v) {return qVectorVec3ToScriptValue(e, v); }
+inline ScriptValue qVectorVec3Color_convertScriptValue(ScriptEngine* e, const QVector<glm::vec3>& v) {return qVectorVec3ColorToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QVector<glm::quat>& v) {return qVectorQuatToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QVector<bool>& v) {return qVectorBoolToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QVector<float>& v) { return qVectorFloatToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QVector<QUuid>& v) { return qVectorQUuidToScriptValue(e, v); }
+
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QRect& v) { return qRectToScriptValue(e, v); }
+
+inline ScriptValue convertScriptValue(ScriptEngine* e, const QByteArray& v) {
     QByteArray b64 = v.toBase64();
-    return QScriptValue(QString(b64));
+    return e->newValue(QString(b64));
 }
 
-inline QScriptValue convertScriptValue(QScriptEngine* e, const EntityItemID& v) { return QScriptValue(QUuid(v).toString()); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const EntityItemID& v) { return e->newValue(QUuid(v).toString()); }
 
-inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { return aaCubeToScriptValue(e, v); }
+inline ScriptValue convertScriptValue(ScriptEngine* e, const AACube& v) { return aaCubeToScriptValue(e, v); }
 
 #define COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(X,G,g,P,p) \
     if ((desiredProperties.isEmpty() || desiredProperties.getHasProperty(X)) && \
         (!skipDefaults || defaultEntityProperties.get##G().get##P() != get##P())) { \
-        QScriptValue groupProperties = properties.property(#g); \
+        ScriptValue groupProperties = properties.property(#g); \
         if (!groupProperties.isValid()) { \
             groupProperties = engine->newObject(); \
         } \
-        QScriptValue V = convertScriptValue(engine, get##P()); \
+        ScriptValue V = convertScriptValue(engine, get##P()); \
         groupProperties.setProperty(#p, V); \
         properties.setProperty(#g, groupProperties); \
     }
@@ -147,11 +150,11 @@ inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { retu
 #define COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(X,G,g,P,p,T) \
     if ((desiredProperties.isEmpty() || desiredProperties.getHasProperty(X)) && \
         (!skipDefaults || defaultEntityProperties.get##G().get##P() != get##P())) { \
-        QScriptValue groupProperties = properties.property(#g); \
+        ScriptValue groupProperties = properties.property(#g); \
         if (!groupProperties.isValid()) { \
             groupProperties = engine->newObject(); \
         } \
-        QScriptValue V = T##_convertScriptValue(engine, get##P()); \
+        ScriptValue V = T##_convertScriptValue(engine, get##P()); \
         groupProperties.setProperty(#p, V); \
         properties.setProperty(#g, groupProperties); \
     }
@@ -159,11 +162,11 @@ inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { retu
 #define COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_GETTER(X,G,g,P,p,M)                       \
     if ((desiredProperties.isEmpty() || desiredProperties.getHasProperty(X)) &&       \
         (!skipDefaults || defaultEntityProperties.get##G().get##P() != get##P())) {   \
-        QScriptValue groupProperties = properties.property(#g);                       \
+        ScriptValue groupProperties = properties.property(#g);                        \
         if (!groupProperties.isValid()) {                                             \
             groupProperties = engine->newObject();                                    \
         }                                                                             \
-        QScriptValue V = convertScriptValue(engine, M());                             \
+        ScriptValue V = convertScriptValue(engine, M());                              \
         groupProperties.setProperty(#p, V);                                           \
         properties.setProperty(#g, groupProperties);                                  \
     }
@@ -171,14 +174,14 @@ inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { retu
 #define COPY_PROPERTY_TO_QSCRIPTVALUE(p,P) \
     if (((!psuedoPropertyFlagsButDesiredEmpty && _desiredProperties.isEmpty()) || _desiredProperties.getHasProperty(p)) && \
         (!skipDefaults || defaultEntityProperties._##P != _##P)) { \
-        QScriptValue V = convertScriptValue(engine, _##P); \
+        ScriptValue V = convertScriptValue(engine, _##P); \
         properties.setProperty(#P, V); \
     }
 
 #define COPY_PROPERTY_TO_QSCRIPTVALUE_TYPED(p,P,T) \
     if ((_desiredProperties.isEmpty() || _desiredProperties.getHasProperty(p)) && \
         (!skipDefaults || defaultEntityProperties._##P != _##P)) { \
-        QScriptValue V = T##_convertScriptValue(engine, _##P); \
+        ScriptValue V = T##_convertScriptValue(engine, _##P); \
         properties.setProperty(#P, V); \
     }
 
@@ -188,14 +191,14 @@ inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { retu
 #define COPY_PROPERTY_TO_QSCRIPTVALUE_GETTER(p, P, G) \
     if (((!psuedoPropertyFlagsButDesiredEmpty && _desiredProperties.isEmpty()) || _desiredProperties.getHasProperty(p)) && \
         (!skipDefaults || defaultEntityProperties._##P != _##P)) { \
-        QScriptValue V = convertScriptValue(engine, G); \
+        ScriptValue V = convertScriptValue(engine, G); \
         properties.setProperty(#P, V); \
     }
 
 #define COPY_PROPERTY_TO_QSCRIPTVALUE_GETTER_TYPED(p, P, G, T) \
     if ((_desiredProperties.isEmpty() || _desiredProperties.getHasProperty(p)) && \
         (!skipDefaults || defaultEntityProperties._##P != _##P)) { \
-        QScriptValue V = T##_convertScriptValue(engine, G); \
+        ScriptValue V = T##_convertScriptValue(engine, G); \
         properties.setProperty(#P, V); \
     }
 
@@ -203,13 +206,13 @@ inline QScriptValue convertScriptValue(QScriptEngine* e, const AACube& v) { retu
 #define COPY_PROXY_PROPERTY_TO_QSCRIPTVALUE_GETTER(p, P, X, G) \
     if (((!psuedoPropertyFlagsButDesiredEmpty && _desiredProperties.isEmpty()) || _desiredProperties.getHasProperty(p)) && \
         (!skipDefaults || defaultEntityProperties._##P != _##P)) { \
-        QScriptValue V = convertScriptValue(engine, G); \
+        ScriptValue V = convertScriptValue(engine, G); \
         properties.setProperty(#X, V); \
     }
 
 #define COPY_PROPERTY_TO_QSCRIPTVALUE_GETTER_ALWAYS(P, G) \
     if (!skipDefaults || defaultEntityProperties._##P != _##P) { \
-        QScriptValue V = convertScriptValue(engine, G); \
+        ScriptValue V = convertScriptValue(engine, G); \
         properties.setProperty(#P, V); \
     }
 
@@ -218,94 +221,94 @@ typedef QVector<glm::quat> qVectorQuat;
 typedef QVector<bool> qVectorBool;
 typedef QVector<float> qVectorFloat;
 typedef QVector<QUuid> qVectorQUuid;
-inline float float_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toFloat(&isValid); }
-inline quint64 quint64_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toULongLong(&isValid); }
-inline quint32 quint32_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline float float_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toFloat(&isValid); }
+inline quint64 quint64_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toULongLong(&isValid); }
+inline quint32 quint32_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     // Use QString::toUInt() so that isValid is set to false if the number is outside the quint32 range.
     return v.toString().toUInt(&isValid);
 }
-inline quint16 quint16_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
-inline uint16_t uint16_t_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
-inline uint32_t uint32_t_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
-inline int int_convertFromScriptValue(const QScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
-inline bool bool_convertFromScriptValue(const QScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toBool(); }
-inline uint8_t uint8_t_convertFromScriptValue(const QScriptValue& v, bool& isValid) { isValid = true; return (uint8_t)(0xff & v.toVariant().toInt(&isValid)); }
-inline QString QString_convertFromScriptValue(const QScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toString().trimmed(); }
-inline QUuid QUuid_convertFromScriptValue(const QScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toUuid(); }
-inline EntityItemID EntityItemID_convertFromScriptValue(const QScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toUuid(); }
-
-inline QByteArray QByteArray_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline quint16 quint16_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
+inline uint16_t uint16_t_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
+inline uint32_t uint32_t_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
+inline int int_convertFromScriptValue(const ScriptValue& v, bool& isValid) { return v.toVariant().toInt(&isValid); }
+inline bool bool_convertFromScriptValue(const ScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toBool(); }
+inline uint8_t uint8_t_convertFromScriptValue(const ScriptValue& v, bool& isValid) { isValid = true; return (uint8_t)(0xff & v.toVariant().toInt(&isValid)); }
+inline QString QString_convertFromScriptValue(const ScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toString().trimmed(); }
+inline QUuid QUuid_convertFromScriptValue(const ScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toUuid(); }
+inline EntityItemID EntityItemID_convertFromScriptValue(const ScriptValue& v, bool& isValid) { isValid = true; return v.toVariant().toUuid(); }
+
+inline QByteArray QByteArray_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     QString b64 = v.toVariant().toString().trimmed();
     return QByteArray::fromBase64(b64.toUtf8());
 }
 
-inline glm::vec2 vec2_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline glm::vec2 vec2_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     glm::vec2 vec2;
     vec2FromScriptValue(v, vec2);
     return vec2;
 }
 
-inline glm::vec3 vec3_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline glm::vec3 vec3_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     glm::vec3 vec3;
     vec3FromScriptValue(v, vec3);
     return vec3;
 }
 
-inline glm::vec3 vec3Color_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline glm::vec3 vec3Color_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     glm::vec3 vec3;
     vec3FromScriptValue(v, vec3);
     return vec3;
 }
 
-inline glm::u8vec3 u8vec3Color_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline glm::u8vec3 u8vec3Color_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     glm::u8vec3 vec3;
     u8vec3FromScriptValue(v, vec3);
     return vec3;
 }
 
-inline AACube AACube_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline AACube AACube_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     AACube result;
     aaCubeFromScriptValue(v, result);
     return result;
 }
 
-inline qVectorFloat qVectorFloat_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline qVectorFloat qVectorFloat_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     return qVectorFloatFromScriptValue(v);
 }
 
-inline qVectorVec3 qVectorVec3_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline qVectorVec3 qVectorVec3_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     return qVectorVec3FromScriptValue(v);
 }
 
-inline qVectorQuat qVectorQuat_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline qVectorQuat qVectorQuat_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     return qVectorQuatFromScriptValue(v);
 }
 
-inline qVectorBool qVectorBool_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline qVectorBool qVectorBool_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     return qVectorBoolFromScriptValue(v);
 }
 
-inline qVectorQUuid qVectorQUuid_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline qVectorQUuid qVectorQUuid_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     return qVectorQUuidFromScriptValue(v);
 }
 
-inline glm::quat quat_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline glm::quat quat_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = false; /// assume it can't be converted
-    QScriptValue x = v.property("x");
-    QScriptValue y = v.property("y");
-    QScriptValue z = v.property("z");
-    QScriptValue w = v.property("w");
+    ScriptValue x = v.property("x");
+    ScriptValue y = v.property("y");
+    ScriptValue z = v.property("z");
+    ScriptValue w = v.property("w");
     if (x.isValid() && y.isValid() && z.isValid() && w.isValid()) {
         glm::quat newValue;
         newValue.x = x.toVariant().toFloat();
@@ -323,7 +326,7 @@ inline glm::quat quat_convertFromScriptValue(const QScriptValue& v, bool& isVali
     return glm::quat();
 }
 
-inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid) {
+inline QRect QRect_convertFromScriptValue(const ScriptValue& v, bool& isValid) {
     isValid = true;
     QRect rect;
     qRectFromScriptValue(v, rect);
@@ -341,7 +344,7 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_PROPERTY_FROM_QSCRIPTVALUE(P, T, S)                     \
     {                                                                \
-        QScriptValue V = object.property(#P);                        \
+        ScriptValue V = object.property(#P);                         \
         if (V.isValid()) {                                           \
             bool isValid = false;                                    \
             T newValue = T##_convertFromScriptValue(V, isValid);     \
@@ -353,7 +356,7 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_PROPERTY_FROM_QSCRIPTVALUE_GETTER(P, T, S, G)      \
 {                                                               \
-    QScriptValue V = object.property(#P);                       \
+    ScriptValue V = object.property(#P);                        \
     if (V.isValid()) {                                          \
         bool isValid = false;                                   \
         T newValue = T##_convertFromScriptValue(V, isValid);    \
@@ -365,7 +368,7 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_PROPERTY_FROM_QSCRIPTVALUE_NOCHECK(P, T, S)     \
 {                                                            \
-    QScriptValue V = object.property(#P);                    \
+    ScriptValue V = object.property(#P);                     \
     if (V.isValid()) {                                       \
         bool isValid = false;                                \
         T newValue = T##_convertFromScriptValue(V, isValid); \
@@ -377,9 +380,9 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(G, P, T, S)                \
     {                                                                    \
-        QScriptValue G = object.property(#G);                            \
+        ScriptValue G = object.property(#G);                             \
         if (G.isValid()) {                                               \
-            QScriptValue V = G.property(#P);                             \
+            ScriptValue V = G.property(#P);                              \
             if (V.isValid()) {                                           \
                 bool isValid = false;                                    \
                 T newValue = T##_convertFromScriptValue(V, isValid);     \
@@ -392,7 +395,7 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_PROPERTY_FROM_QSCRIPTVALUE_ENUM(P, S)                    \
     {                                                                 \
-        QScriptValue P = object.property(#P);                         \
+        ScriptValue P = object.property(#P);                          \
         if (P.isValid()) {                                            \
             QString newValue = P.toVariant().toString();              \
             if (_defaultSettings || newValue != get##S##AsString()) { \
@@ -403,9 +406,9 @@ inline QRect QRect_convertFromScriptValue(const QScriptValue& v, bool& isValid)
 
 #define COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE_ENUM(G, P, S)               \
     {                                                                     \
-        QScriptValue G = object.property(#G);                             \
+        ScriptValue G = object.property(#G);                              \
         if (G.isValid()) {                                                \
-            QScriptValue P = G.property(#P);                              \
+            ScriptValue P = G.property(#P);                               \
             if (P.isValid()) {                                            \
                 QString newValue = P.toVariant().toString();              \
                 if (_defaultSettings || newValue != get##S##AsString()) { \
diff --git a/libraries/entities/src/EntityScriptingInterface.cpp b/libraries/entities/src/EntityScriptingInterface.cpp
index 90c521215e9..f93ad4ef97b 100644
--- a/libraries/entities/src/EntityScriptingInterface.cpp
+++ b/libraries/entities/src/EntityScriptingInterface.cpp
@@ -41,10 +41,43 @@
 #include <EntityScriptClient.h>
 #include <Profile.h>
 #include "GrabPropertyGroup.h"
+#include <ScriptContext.h>
+#include <ScriptEngineCast.h>
+#include <ScriptValue.h>
 
 const QString GRABBABLE_USER_DATA = "{\"grabbableKey\":{\"grabbable\":true}}";
 const QString NOT_GRABBABLE_USER_DATA = "{\"grabbableKey\":{\"grabbable\":false}}";
 
+void staticEntityScriptInitializer(ScriptManager* manager) {
+    auto scriptEngine = manager->engine().get();
+
+    auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
+    entityScriptingInterface->init();
+    auto interfacePtr = entityScriptingInterface.data();  // using this when we don't want to leak a reference
+
+    registerMetaTypes(scriptEngine);
+
+    scriptRegisterMetaType(scriptEngine, EntityPropertyFlagsToScriptValue, EntityPropertyFlagsFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, EntityItemPropertiesToScriptValue, EntityItemPropertiesFromScriptValueHonorReadOnly);
+    scriptRegisterMetaType(scriptEngine, EntityPropertyInfoToScriptValue, EntityPropertyInfoFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, EntityItemIDtoScriptValue, EntityItemIDfromScriptValue);
+    scriptRegisterMetaType(scriptEngine, RayToEntityIntersectionResultToScriptValue, RayToEntityIntersectionResultFromScriptValue);
+
+    scriptEngine->registerGlobalObject("Entities", entityScriptingInterface.data());
+    scriptEngine->registerFunction("Entities", "getMultipleEntityProperties", EntityScriptingInterface::getMultipleEntityProperties);
+
+    // "The return value of QObject::sender() is not valid when the slot is called via a Qt::DirectConnection from a thread
+    // different from this object's thread. Do not use this function in this type of scenario."
+    // so... yay lambdas everywhere to get the sender
+    manager->connect(
+        manager, &ScriptManager::attachDefaultEventHandlers, entityScriptingInterface.data(),
+        [interfacePtr, manager] { interfacePtr->attachDefaultEventHandlers(manager); },
+        Qt::DirectConnection);
+    manager->connect(manager, &ScriptManager::releaseEntityPacketSenderMessages, entityScriptingInterface.data(),
+                     &EntityScriptingInterface::releaseEntityPacketSenderMessages, Qt::DirectConnection);
+}
+STATIC_SCRIPT_INITIALIZER(staticEntityScriptInitializer);
+
 EntityScriptingInterface::EntityScriptingInterface(bool bidOnSimulationOwnership) :
     _entityTree(nullptr),
     _bidOnSimulationOwnership(bidOnSimulationOwnership)
@@ -64,6 +97,148 @@ EntityScriptingInterface::EntityScriptingInterface(bool bidOnSimulationOwnership
         PacketReceiver::makeSourcedListenerReference<EntityScriptingInterface>(this, &EntityScriptingInterface::handleEntityScriptCallMethodPacket));
 }
 
+void EntityScriptingInterface::releaseEntityPacketSenderMessages(bool wait) {
+    EntityEditPacketSender* entityPacketSender = getEntityPacketSender();
+    if (entityPacketSender && entityPacketSender->serversExist()) {
+        // release the queue of edit entity messages.
+        entityPacketSender->releaseQueuedMessages();
+
+        // since we're in non-threaded mode, call process so that the packets are sent
+        if (!entityPacketSender->isThreaded()) {
+            if (!wait) {
+                entityPacketSender->process();
+            } else {
+                // wait here till the edit packet sender is completely done sending
+                while (entityPacketSender->hasPacketsToSend()) {
+                    entityPacketSender->process();
+                    QCoreApplication::processEvents();
+                }
+            }
+        } else {
+            // FIXME - do we need to have a similar "wait here" loop for non-threaded packet senders?
+        }
+    }
+}
+
+
+void EntityScriptingInterface::attachDefaultEventHandlers(ScriptManager* manager) {
+    // Connect up ALL the handlers to the global entities object's signals.
+    // (We could go signal by signal, or even handler by handler, but I don't think the efficiency is worth the complexity.)
+    
+    // Bug? These handlers are deleted when entityID is deleted, which is nice.
+    // But if they are created by an entity script on a different entity, should they also be deleted when the entity script unloads?
+    // E.g., suppose a bow has an entity script that causes arrows to be created with a potential lifetime greater than the bow,
+    // and that the entity script adds (e.g., collision) handlers to the arrows. Should those handlers fire if the bow is unloaded?
+    // Also, what about when the entity script is REloaded?
+    // For now, we are leaving them around. Changing that would require some non-trivial digging around to find the
+    // handlers that were added while a given currentEntityIdentifier was in place. I don't think this is dangerous. Just perhaps unexpected. -HRS
+    connect(this, &EntityScriptingInterface::deletingEntity, manager,
+            [manager](const EntityItemID& entityID) { manager->removeAllEventHandlers(entityID); });
+
+    // Two common cases of event handler, differing only in argument signature.
+
+    /*@jsdoc
+         * Called when an entity event occurs on an entity as registered with {@link Script.addEventHandler}.
+         * @callback Script~entityEventCallback
+         * @param {Uuid} entityID - The ID of the entity the event has occured on.
+         */
+    using SingleEntityHandler = std::function<void(const EntityItemID&)>;
+    auto makeSingleEntityHandler = [manager](QString eventName) -> SingleEntityHandler {
+        return [manager, eventName](const EntityItemID& entityItemID) {
+            manager->forwardHandlerCall(entityItemID, eventName,
+                                        { EntityItemIDtoScriptValue(manager->engine().get(), entityItemID) });
+        };
+    };
+
+    /*@jsdoc
+         * Called when a pointer event occurs on an entity as registered with {@link Script.addEventHandler}.
+         * @callback Script~pointerEventCallback
+         * @param {Uuid} entityID - The ID of the entity the event has occurred on.
+         * @param {PointerEvent} pointerEvent - Details of the event.
+         */
+    using PointerHandler = std::function<void(const EntityItemID&, const PointerEvent&)>;
+    auto makePointerHandler = [manager](QString eventName) -> PointerHandler {
+        return [manager, eventName](const EntityItemID& entityItemID, const PointerEvent& event) {
+            if (!EntityTree::areEntityClicksCaptured()) {
+                ScriptEngine* engine = manager->engine().get();
+                manager->forwardHandlerCall(entityItemID, eventName,
+                                            { EntityItemIDtoScriptValue(engine, entityItemID), event.toScriptValue(engine) });
+            }
+        };
+    };
+
+    /*@jsdoc
+         * Called when a collision event occurs on an entity as registered with {@link Script.addEventHandler}.
+         * @callback Script~collisionEventCallback
+         * @param {Uuid} entityA - The ID of one entity in the collision.
+         * @param {Uuid} entityB - The ID of the other entity in the collision.
+         * @param {Collision} collisionEvent - Details of the collision.
+         */
+    using CollisionHandler = std::function<void(const EntityItemID&, const EntityItemID&, const Collision&)>;
+    auto makeCollisionHandler = [manager](QString eventName) -> CollisionHandler {
+        return [manager, eventName](const EntityItemID& idA, const EntityItemID& idB, const Collision& collision) {
+            ScriptEngine* engine = manager->engine().get();
+            manager->forwardHandlerCall(idA, eventName,
+                                        { EntityItemIDtoScriptValue(engine, idA),
+                                          EntityItemIDtoScriptValue(engine, idB),
+                                          collisionToScriptValue(engine, collision) });
+        };
+    };
+
+    /*@jsdoc
+         * <p>The name of an entity event. When the entity event occurs, any function that has been registered for that event 
+         * via {@link Script.addEventHandler} is called with parameters per the entity event.</p>
+         * <table>
+         *   <thead>
+         *     <tr><th>Event Name</th><th>Callback Type</th><th>Entity Event</th></tr>
+         *   </thead>
+         *   <tbody>
+         *     <tr><td><code>"enterEntity"</code></td><td>{@link Script~entityEventCallback|entityEventCallback}</td>
+         *       <td>{@link Entities.enterEntity}</td></tr>
+         *     <tr><td><code>"leaveEntity"</code></td><td>{@link Script~entityEventCallback|entityEventCallback}</td>
+         *       <td>{@link Entities.leaveEntity}</td></tr>
+         *     <tr><td><code>"mousePressOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.mousePressOnEntity}</td></tr>
+         *     <tr><td><code>"mouseMoveOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.mouseMoveOnEntity}</td></tr>
+         *     <tr><td><code>"mouseReleaseOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.mouseReleaseOnEntity}</td></tr>
+         *     <tr><td><code>"clickDownOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.clickDownOnEntity}</td></tr>
+         *     <tr><td><code>"holdingClickOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.holdingClickOnEntity}</td></tr>
+         *     <tr><td><code>"clickReleaseOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.clickReleaseOnEntity}</td></tr>
+         *     <tr><td><code>"hoverEnterEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.hoverEnterEntity}</td></tr>
+         *     <tr><td><code>"hoverOverEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.hoverOverEntity}</td></tr>
+         *     <tr><td><code>"hoverLeaveEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
+         *       <td>{@link Entities.hoverLeaveEntity}</td></tr>
+         *     <tr><td><code>"collisionWithEntity"</code><td>{@link Script~collisionEventCallback|collisionEventCallback}</td>
+         *       </td><td>{@link Entities.collisionWithEntity}</td></tr>
+         *   </tbody>
+         * </table>
+         * @typedef {string} Script.EntityEvent
+         */
+    connect(this, &EntityScriptingInterface::enterEntity, manager, makeSingleEntityHandler("enterEntity"));
+    connect(this, &EntityScriptingInterface::leaveEntity, manager, makeSingleEntityHandler("leaveEntity"));
+
+    connect(this, &EntityScriptingInterface::mousePressOnEntity, manager, makePointerHandler("mousePressOnEntity"));
+    connect(this, &EntityScriptingInterface::mouseMoveOnEntity, manager, makePointerHandler("mouseMoveOnEntity"));
+    connect(this, &EntityScriptingInterface::mouseReleaseOnEntity, manager, makePointerHandler("mouseReleaseOnEntity"));
+
+    connect(this, &EntityScriptingInterface::clickDownOnEntity, manager, makePointerHandler("clickDownOnEntity"));
+    connect(this, &EntityScriptingInterface::holdingClickOnEntity, manager, makePointerHandler("holdingClickOnEntity"));
+    connect(this, &EntityScriptingInterface::clickReleaseOnEntity, manager, makePointerHandler("clickReleaseOnEntity"));
+
+    connect(this, &EntityScriptingInterface::hoverEnterEntity, manager, makePointerHandler("hoverEnterEntity"));
+    connect(this, &EntityScriptingInterface::hoverOverEntity, manager, makePointerHandler("hoverOverEntity"));
+    connect(this, &EntityScriptingInterface::hoverLeaveEntity, manager, makePointerHandler("hoverLeaveEntity"));
+
+    connect(this, &EntityScriptingInterface::collisionWithEntity, manager, makeCollisionHandler("collisionWithEntity"));
+}
+
 void EntityScriptingInterface::queueEntityMessage(PacketType packetType,
                                                   EntityItemID entityID, const EntityItemProperties& properties) {
     getEntityPacketSender()->queueEditEntityMessage(packetType, _entityTree, entityID, properties);
@@ -672,20 +847,20 @@ struct EntityPropertiesResult {
 
 // Static method to make sure that we have the right script engine.
 // Using sender() or QtScriptable::engine() does not work for classes used by multiple threads (script-engines)
-QScriptValue EntityScriptingInterface::getMultipleEntityProperties(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue EntityScriptingInterface::getMultipleEntityProperties(ScriptContext* context, ScriptEngine* engine) {
     const int ARGUMENT_ENTITY_IDS = 0;
     const int ARGUMENT_EXTENDED_DESIRED_PROPERTIES = 1;
 
     auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
-    const auto entityIDs = qscriptvalue_cast<QVector<QUuid>>(context->argument(ARGUMENT_ENTITY_IDS));
+    const auto entityIDs = scriptvalue_cast<QVector<QUuid>>(context->argument(ARGUMENT_ENTITY_IDS));
     return entityScriptingInterface->getMultipleEntityPropertiesInternal(engine, entityIDs, context->argument(ARGUMENT_EXTENDED_DESIRED_PROPERTIES));
 }
 
-QScriptValue EntityScriptingInterface::getMultipleEntityPropertiesInternal(QScriptEngine* engine, QVector<QUuid> entityIDs, const QScriptValue& extendedDesiredProperties) {
+ScriptValue EntityScriptingInterface::getMultipleEntityPropertiesInternal(ScriptEngine* engine, QVector<QUuid> entityIDs, const ScriptValue& extendedDesiredProperties) {
     PROFILE_RANGE(script_entities, __FUNCTION__);
 
     EntityPsuedoPropertyFlags psuedoPropertyFlags;
-    const auto readExtendedPropertyStringValue = [&](QScriptValue extendedProperty) {
+    const auto readExtendedPropertyStringValue = [&](ScriptValue extendedProperty) {
         const auto extendedPropertyString = extendedProperty.toString();
         if (extendedPropertyString == "id") {
             psuedoPropertyFlags.set(EntityPsuedoPropertyFlag::ID);
@@ -727,7 +902,7 @@ QScriptValue EntityScriptingInterface::getMultipleEntityPropertiesInternal(QScri
         psuedoPropertyFlags.set(EntityPsuedoPropertyFlag::FlagsActive);
     }
 
-    EntityPropertyFlags desiredProperties = qscriptvalue_cast<EntityPropertyFlags>(extendedDesiredProperties);
+    EntityPropertyFlags desiredProperties = scriptvalue_cast<EntityPropertyFlags>(extendedDesiredProperties);
     bool needsScriptSemantics = desiredProperties.getHasProperty(PROP_POSITION) ||
         desiredProperties.getHasProperty(PROP_ROTATION) ||
         desiredProperties.getHasProperty(PROP_LOCAL_POSITION) ||
@@ -774,7 +949,7 @@ QScriptValue EntityScriptingInterface::getMultipleEntityPropertiesInternal(QScri
             });
         }
     }
-    QScriptValue finalResult = engine->newArray(resultProperties.size());
+    ScriptValue finalResult = engine->newArray(resultProperties.size());
     quint32 i = 0;
     if (needsScriptSemantics) {
         PROFILE_RANGE(script_entities, "EntityScriptingInterface::getMultipleEntityProperties>Script Semantics");
@@ -1060,14 +1235,14 @@ QSizeF EntityScriptingInterface::textSize(const QUuid& id, const QString& text)
     return EntityTree::textSize(id, text);
 }
 
-void EntityScriptingInterface::setPersistentEntitiesScriptEngine(QSharedPointer<EntitiesScriptEngineProvider> engine) {
+void EntityScriptingInterface::setPersistentEntitiesScriptEngine(std::shared_ptr<EntitiesScriptEngineProvider> manager) {
     std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
-    _persistentEntitiesScriptEngine = engine;
+    _persistentEntitiesScriptManager = manager;
 }
 
-void EntityScriptingInterface::setNonPersistentEntitiesScriptEngine(QSharedPointer<EntitiesScriptEngineProvider> engine) {
+void EntityScriptingInterface::setNonPersistentEntitiesScriptEngine(std::shared_ptr<EntitiesScriptEngineProvider> manager) {
     std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
-    _nonPersistentEntitiesScriptEngine = engine;
+    _nonPersistentEntitiesScriptManager = manager;
 }
 
 void EntityScriptingInterface::callEntityMethod(const QUuid& id, const QString& method, const QStringList& params) {
@@ -1076,7 +1251,7 @@ void EntityScriptingInterface::callEntityMethod(const QUuid& id, const QString&
     auto entity = getEntityTree()->findEntityByEntityItemID(id);
     if (entity) {
         std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
-        auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+        auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
         if (scriptEngine) {
             scriptEngine->callEntityScriptMethod(id, method, params);
         }
@@ -1124,7 +1299,7 @@ void EntityScriptingInterface::handleEntityScriptCallMethodPacket(QSharedPointer
         auto entity = getEntityTree()->findEntityByEntityItemID(entityID);
         if (entity) {
             std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
-            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine;
+            auto& scriptEngine = (entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager;
             if (scriptEngine) {
                 scriptEngine->callEntityScriptMethod(entityID, method, params, senderNode->getUUID());
             }
@@ -1258,7 +1433,7 @@ QVector<QUuid> EntityScriptingInterface::findEntitiesByName(const QString entity
 }
 
 RayToEntityIntersectionResult EntityScriptingInterface::findRayIntersection(const PickRay& ray, bool precisionPicking,
-        const QScriptValue& entityIdsToInclude, const QScriptValue& entityIdsToDiscard, bool visibleOnly, bool collidableOnly) const {
+        const ScriptValue& entityIdsToInclude, const ScriptValue& entityIdsToDiscard, bool visibleOnly, bool collidableOnly) const {
     PROFILE_RANGE(script_entities, __FUNCTION__);
     QVector<EntityItemID> entitiesToInclude = qVectorEntityItemIDFromScriptValue(entityIdsToInclude);
     QVector<EntityItemID> entitiesToDiscard = qVectorEntityItemIDFromScriptValue(entityIdsToDiscard);
@@ -1334,46 +1509,47 @@ bool EntityScriptingInterface::reloadServerScripts(const QUuid& entityID) {
     return client->reloadServerScript(entityID);
 }
 
-bool EntityPropertyMetadataRequest::script(EntityItemID entityID, QScriptValue handler) {
+bool EntityPropertyMetadataRequest::script(EntityItemID entityID, const ScriptValue& handler) {
     using LocalScriptStatusRequest = QFutureWatcher<QVariant>;
 
     LocalScriptStatusRequest* request = new LocalScriptStatusRequest;
-    QObject::connect(request, &LocalScriptStatusRequest::finished, _engine, [=]() mutable {
+    QObject::connect(request, &LocalScriptStatusRequest::finished, _scriptManager, [=]() mutable {
         auto details = request->result().toMap();
-        QScriptValue err, result;
+        ScriptValue err, result;
         if (details.contains("isError")) {
             if (!details.contains("message")) {
                 details["message"] = details["errorInfo"];
             }
-            err = _engine->makeError(_engine->toScriptValue(details));
+            err = _scriptManager->engine()->makeError(_scriptManager->engine()->toScriptValue(details));
         } else {
             details["success"] = true;
-            result = _engine->toScriptValue(details);
+            result = _scriptManager->engine()->toScriptValue(details);
         }
         callScopedHandlerObject(handler, err, result);
         request->deleteLater();
     });
     auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
-    entityScriptingInterface->withEntitiesScriptEngine([&](QSharedPointer<EntitiesScriptEngineProvider> entitiesScriptEngine) {
+    entityScriptingInterface->withEntitiesScriptEngine([&](std::shared_ptr<EntitiesScriptEngineProvider> entitiesScriptEngine) {
         if (entitiesScriptEngine) {
             request->setFuture(entitiesScriptEngine->getLocalEntityScriptDetails(entityID));
         }
     }, entityID);
     if (!request->isStarted()) {
         request->deleteLater();
-        callScopedHandlerObject(handler, _engine->makeError("Entities Scripting Provider unavailable", "InternalError"), QScriptValue());
+        auto engine = handler.engine();
+        callScopedHandlerObject(handler, engine->makeError(engine->newValue("Entities Scripting Provider unavailable"), "InternalError"), ScriptValue());
         return false;
     }
     return true;
 }
 
-bool EntityPropertyMetadataRequest::serverScripts(EntityItemID entityID, QScriptValue handler) {
+bool EntityPropertyMetadataRequest::serverScripts(EntityItemID entityID, const ScriptValue& handler) {
     auto client = DependencyManager::get<EntityScriptClient>();
     auto request = client->createScriptStatusRequest(entityID);
-    QPointer<BaseScriptEngine> engine = _engine;
-    QObject::connect(request, &GetScriptStatusRequest::finished, _engine, [=](GetScriptStatusRequest* request) mutable {
-        auto engine = _engine;
-        if (!engine) {
+    QPointer<ScriptManager> manager = _scriptManager;
+    QObject::connect(request, &GetScriptStatusRequest::finished, _scriptManager, [=](GetScriptStatusRequest* request) mutable {
+        auto manager = _scriptManager;
+        if (!manager) {
             qCDebug(entities) << __FUNCTION__ << " -- engine destroyed while inflight" << entityID;
             return;
         }
@@ -1383,7 +1559,7 @@ bool EntityPropertyMetadataRequest::serverScripts(EntityItemID entityID, QScript
         details["status"] = EntityScriptStatus_::valueToKey(request->getStatus()).toLower();
         details["errorInfo"] = request->getErrorInfo();
 
-        QScriptValue err, result;
+        ScriptValue err, result;
         if (!details["success"].toBool()) {
             if (!details.contains("message") && details.contains("errorInfo")) {
                 details["message"] = details["errorInfo"];
@@ -1391,9 +1567,9 @@ bool EntityPropertyMetadataRequest::serverScripts(EntityItemID entityID, QScript
             if (details["message"].toString().isEmpty()) {
                 details["message"] = "entity server script details not found";
             }
-            err = engine->makeError(engine->toScriptValue(details));
+            err = manager->engine()->makeError(manager->engine()->toScriptValue(details));
         } else {
-            result = engine->toScriptValue(details);
+            result = manager->engine()->toScriptValue(details);
         }
         callScopedHandlerObject(handler, err, result);
         request->deleteLater();
@@ -1402,22 +1578,26 @@ bool EntityPropertyMetadataRequest::serverScripts(EntityItemID entityID, QScript
     return true;
 }
 
-bool EntityScriptingInterface::queryPropertyMetadata(const QUuid& entityID, QScriptValue property, QScriptValue scopeOrCallback, QScriptValue methodOrName) {
+bool EntityScriptingInterface::queryPropertyMetadata(const QUuid& entityID,
+                                                     const ScriptValue& property,
+                                                     const ScriptValue& scopeOrCallback,
+                                                     const ScriptValue& methodOrName) {
     auto name = property.toString();
     auto handler = makeScopedHandlerObject(scopeOrCallback, methodOrName);
-    QPointer<BaseScriptEngine> engine = dynamic_cast<BaseScriptEngine*>(handler.engine());
-    if (!engine) {
-        qCDebug(entities) << "queryPropertyMetadata without detectable engine" << entityID << name;
+    QPointer<ScriptManager> manager = handler.engine()->manager();
+    if (!manager) {
+        qCDebug(entities) << "queryPropertyMetadata without detectable script manager" << entityID << name;
         return false;
     }
+    auto engine = manager->engine();
 #ifdef DEBUG_ENGINE_STATE
     connect(engine, &QObject::destroyed, this, [=]() {
         qDebug() << "queryPropertyMetadata -- engine destroyed!" << (!engine ? "nullptr" : "engine");
     });
 #endif
     if (!handler.property("callback").isFunction()) {
-        qDebug() << "!handler.callback.isFunction" << engine;
-        engine->raiseException(engine->makeError("callback is not a function", "TypeError"));
+        qDebug() << "!handler.callback.isFunction" << manager;
+        engine->raiseException(engine->makeError(engine->newValue("callback is not a function"), "TypeError"));
         return false;
     }
 
@@ -1433,26 +1613,36 @@ bool EntityScriptingInterface::queryPropertyMetadata(const QUuid& entityID, QScr
 
     // This is an async callback pattern -- so if needed C++ can easily throttle or restrict queries later.
 
-    EntityPropertyMetadataRequest request(engine);
+    EntityPropertyMetadataRequest request(manager);
 
     if (name == "script") {
         return request.script(entityID, handler);
     } else if (name == "serverScripts") {
         return request.serverScripts(entityID, handler);
     } else {
-        engine->raiseException(engine->makeError("metadata for property " + name + " is not yet queryable"));
+        engine->raiseException(engine->makeError(engine->newValue("metadata for property " + name + " is not yet queryable")));
         engine->maybeEmitUncaughtException(__FUNCTION__);
         return false;
     }
 }
 
-bool EntityScriptingInterface::getServerScriptStatus(const QUuid& entityID, QScriptValue callback) {
+bool EntityScriptingInterface::getServerScriptStatus(const QUuid& entityID, const ScriptValue& callback) {
     auto client = DependencyManager::get<EntityScriptClient>();
     auto request = client->createScriptStatusRequest(entityID);
-    connect(request, &GetScriptStatusRequest::finished, callback.engine(), [callback](GetScriptStatusRequest* request) mutable {
-        QString statusString = EntityScriptStatus_::valueToKey(request->getStatus());;
-        QScriptValueList args { request->getResponseReceived(), request->getIsRunning(), statusString.toLower(), request->getErrorInfo() };
-        callback.call(QScriptValue(), args);
+
+    auto engine = callback.engine();
+    auto manager = engine->manager();
+    if (!manager) {
+        engine->raiseException(engine->makeError(engine->newValue("This script does not belong to a ScriptManager")));
+        engine->maybeEmitUncaughtException(__FUNCTION__);
+        return false;
+    }
+
+    connect(request, &GetScriptStatusRequest::finished, manager, [callback](GetScriptStatusRequest* request) mutable {
+        QString statusString = EntityScriptStatus_::valueToKey(request->getStatus());
+        auto engine = callback.engine();
+        ScriptValueList args { engine->newValue(request->getResponseReceived()), engine->newValue(request->getIsRunning()), engine->newValue(statusString.toLower()), engine->newValue(request->getErrorInfo()) };
+        callback.call(ScriptValue(), args);
         request->deleteLater();
     });
     request->start();
@@ -1483,40 +1673,41 @@ bool EntityScriptingInterface::getDrawZoneBoundaries() const {
     return ZoneEntityItem::getDrawZoneBoundaries();
 }
 
-QScriptValue RayToEntityIntersectionResultToScriptValue(QScriptEngine* engine, const RayToEntityIntersectionResult& value) {
-    QScriptValue obj = engine->newObject();
+ScriptValue RayToEntityIntersectionResultToScriptValue(ScriptEngine* engine, const RayToEntityIntersectionResult& value) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("intersects", value.intersects);
     obj.setProperty("accurate", value.accurate);
-    QScriptValue entityItemValue = EntityItemIDtoScriptValue(engine, value.entityID);
+    ScriptValue entityItemValue = EntityItemIDtoScriptValue(engine, value.entityID);
     obj.setProperty("entityID", entityItemValue);
     obj.setProperty("distance", value.distance);
     obj.setProperty("face", boxFaceToString(value.face));
 
-    QScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
+    ScriptValue intersection = vec3ToScriptValue(engine, value.intersection);
     obj.setProperty("intersection", intersection);
-    QScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
+    ScriptValue surfaceNormal = vec3ToScriptValue(engine, value.surfaceNormal);
     obj.setProperty("surfaceNormal", surfaceNormal);
     obj.setProperty("extraInfo", engine->toScriptValue(value.extraInfo));
     return obj;
 }
 
-void RayToEntityIntersectionResultFromScriptValue(const QScriptValue& object, RayToEntityIntersectionResult& value) {
+bool RayToEntityIntersectionResultFromScriptValue(const ScriptValue& object, RayToEntityIntersectionResult& value) {
     value.intersects = object.property("intersects").toVariant().toBool();
     value.accurate = object.property("accurate").toVariant().toBool();
-    QScriptValue entityIDValue = object.property("entityID");
+    ScriptValue entityIDValue = object.property("entityID");
     quuidFromScriptValue(entityIDValue, value.entityID);
     value.distance = object.property("distance").toVariant().toFloat();
     value.face = boxFaceFromString(object.property("face").toVariant().toString());
 
-    QScriptValue intersection = object.property("intersection");
+    ScriptValue intersection = object.property("intersection");
     if (intersection.isValid()) {
         vec3FromScriptValue(intersection, value.intersection);
     }
-    QScriptValue surfaceNormal = object.property("surfaceNormal");
+    ScriptValue surfaceNormal = object.property("surfaceNormal");
     if (surfaceNormal.isValid()) {
         vec3FromScriptValue(surfaceNormal, value.surfaceNormal);
     }
     value.extraInfo = object.property("extraInfo").toVariant().toMap();
+    return true;
 }
 
 bool EntityScriptingInterface::polyVoxWorker(QUuid entityID, std::function<bool(PolyVoxEntityItem&)> actor) {
@@ -2237,14 +2428,15 @@ bool EntityScriptingInterface::AABoxIntersectsCapsule(const glm::vec3& low, cons
     return aaBox.findCapsulePenetration(start, end, radius, penetration);
 }
 
-void EntityScriptingInterface::getMeshes(const QUuid& entityID, QScriptValue callback) {
+void EntityScriptingInterface::getMeshes(const QUuid& entityID, const ScriptValue& callback) {
     PROFILE_RANGE(script_entities, __FUNCTION__);
+    auto engine = callback.engine();
 
     EntityItemPointer entity = static_cast<EntityItemPointer>(_entityTree->findEntityByEntityItemID(entityID));
     if (!entity) {
         qCDebug(entities) << "EntityScriptingInterface::getMeshes no entity with ID" << entityID;
-        QScriptValueList args { callback.engine()->undefinedValue(), false };
-        callback.call(QScriptValue(), args);
+        ScriptValueList args{ engine->undefinedValue(), engine->newValue(false) };
+        callback.call(ScriptValue(), args);
         return;
     }
 
@@ -2252,12 +2444,12 @@ void EntityScriptingInterface::getMeshes(const QUuid& entityID, QScriptValue cal
     bool success = entity->getMeshes(result);
 
     if (success) {
-        QScriptValue resultAsScriptValue = meshesToScriptValue(callback.engine(), result);
-        QScriptValueList args { resultAsScriptValue, true };
-        callback.call(QScriptValue(), args);
+        ScriptValue resultAsScriptValue = meshesToScriptValue(engine.get(), result);
+        ScriptValueList args{ resultAsScriptValue, engine->newValue(true) };
+        callback.call(ScriptValue(), args);
     } else {
-        QScriptValueList args { callback.engine()->undefinedValue(), false };
-        callback.call(QScriptValue(), args);
+        ScriptValueList args{ engine->undefinedValue(), engine->newValue(false) };
+        callback.call(ScriptValue(), args);
     }
 }
 
diff --git a/libraries/entities/src/EntityScriptingInterface.h b/libraries/entities/src/EntityScriptingInterface.h
index 8a3b92f31fa..46208966f1a 100644
--- a/libraries/entities/src/EntityScriptingInterface.h
+++ b/libraries/entities/src/EntityScriptingInterface.h
@@ -15,18 +15,23 @@
 #ifndef hifi_EntityScriptingInterface_h
 #define hifi_EntityScriptingInterface_h
 
+#include <memory>
+
 #include <QtCore/QObject>
 #include <QtCore/QStringList>
 #include <QtCore/QSharedPointer>
 #include <QtQml/QJSValue>
 #include <QtQml/QJSValueList>
+#include <QtCore/QSharedPointer>
 
 #include <DependencyManager.h>
 #include <Octree.h>
 #include <OctreeScriptingInterface.h>
 #include <RegisteredMetaTypes.h>
-#include <PointerEvent.h>
+#include "PointerEvent.h"
 #include <PickFilter.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
 #include "PolyVoxEntityItem.h"
 #include "LineEntityItem.h"
@@ -37,10 +42,10 @@
 #include "EntitiesScriptEngineProvider.h"
 #include "EntityItemProperties.h"
 
-#include "BaseScriptEngine.h"
-
 class EntityTree;
 class MeshProxy;
+class ScriptContext;
+class ScriptEngine;
 
 extern const QString GRABBABLE_USER_DATA;
 extern const QString NOT_GRABBABLE_USER_DATA;
@@ -51,11 +56,11 @@ extern const QString NOT_GRABBABLE_USER_DATA;
 // problems with their own Entity scripts.
 class EntityPropertyMetadataRequest {
 public:
-    EntityPropertyMetadataRequest(BaseScriptEngine* engine) : _engine(engine) {};
-    bool script(EntityItemID entityID, QScriptValue handler);
-    bool serverScripts(EntityItemID entityID, QScriptValue handler);
+    EntityPropertyMetadataRequest(ScriptManager* manager) : _scriptManager(manager){};
+    bool script(EntityItemID entityID, const ScriptValue& handler);
+    bool serverScripts(EntityItemID entityID, const ScriptValue& handler);
 private:
-    QPointer<BaseScriptEngine> _engine;
+    QPointer<ScriptManager> _scriptManager;
 };
 
 /*@jsdoc
@@ -86,8 +91,8 @@ class RayToEntityIntersectionResult {
     QVariantMap extraInfo;
 };
 Q_DECLARE_METATYPE(RayToEntityIntersectionResult)
-QScriptValue RayToEntityIntersectionResultToScriptValue(QScriptEngine* engine, const RayToEntityIntersectionResult& results);
-void RayToEntityIntersectionResultFromScriptValue(const QScriptValue& object, RayToEntityIntersectionResult& results);
+ScriptValue RayToEntityIntersectionResultToScriptValue(ScriptEngine* engine, const RayToEntityIntersectionResult& results);
+bool RayToEntityIntersectionResultFromScriptValue(const ScriptValue& object, RayToEntityIntersectionResult& results);
 
 class ParabolaToEntityIntersectionResult {
 public:
@@ -182,8 +187,8 @@ class EntityScriptingInterface : public OctreeScriptingInterface, public Depende
 
     void setEntityTree(EntityTreePointer modelTree);
     EntityTreePointer getEntityTree() { return _entityTree; }
-    void setPersistentEntitiesScriptEngine(QSharedPointer<EntitiesScriptEngineProvider> engine);
-    void setNonPersistentEntitiesScriptEngine(QSharedPointer<EntitiesScriptEngineProvider> engine);
+    void setPersistentEntitiesScriptEngine(std::shared_ptr<EntitiesScriptEngineProvider> manager);
+    void setNonPersistentEntitiesScriptEngine(std::shared_ptr<EntitiesScriptEngineProvider> manager);
 
     void resetActivityTracking();
     ActivityTracking getActivityTracking() const { return _activityTracking; }
@@ -209,8 +214,8 @@ class EntityScriptingInterface : public OctreeScriptingInterface, public Depende
      * var propertySets = Entities.getMultipleEntityProperties(entityIDs, "name");
      * print("Nearby entity names: " + JSON.stringify(propertySets));
     */
-    static QScriptValue getMultipleEntityProperties(QScriptContext* context, QScriptEngine* engine);
-    QScriptValue getMultipleEntityPropertiesInternal(QScriptEngine* engine, QVector<QUuid> entityIDs, const QScriptValue& extendedDesiredProperties);
+    static ScriptValue getMultipleEntityProperties(ScriptContext* context, ScriptEngine* engine);
+    ScriptValue getMultipleEntityPropertiesInternal(ScriptEngine* engine, QVector<QUuid> entityIDs, const ScriptValue& extendedDesiredProperties);
 
     QUuid addEntityInternal(const EntityItemProperties& properties, entity::HostType entityHostType);
 
@@ -835,7 +840,7 @@ public slots:
     /// may be inaccurate if the engine is unable to access the visible entities, in which case result.accurate
     /// will be false.
     Q_INVOKABLE RayToEntityIntersectionResult findRayIntersection(const PickRay& ray, bool precisionPicking = false,
-            const QScriptValue& entityIdsToInclude = QScriptValue(), const QScriptValue& entityIdsToDiscard = QScriptValue(),
+            const ScriptValue& entityIdsToInclude = ScriptValue(), const ScriptValue& entityIdsToDiscard = ScriptValue(),
             bool visibleOnly = false, bool collidableOnly = false) const;
 
     /*@jsdoc
@@ -864,7 +869,7 @@ public slots:
      * @param {string} errorInfo - <code>""</code> if there is a server entity script running, otherwise it may contain extra 
      *     information on the error.
      */
-    Q_INVOKABLE bool getServerScriptStatus(const QUuid& entityID, QScriptValue callback);
+    Q_INVOKABLE bool getServerScriptStatus(const QUuid& entityID, const ScriptValue& callback);
 
     /*@jsdoc
      * Gets metadata for certain entity properties such as <code>script</code> and <code>serverScripts</code>.
@@ -894,8 +899,8 @@ public slots:
      * @param {object} result - The metadata for the requested entity property if there was no error, otherwise
      *     <code>undefined</code>.
      */
-    Q_INVOKABLE bool queryPropertyMetadata(const QUuid& entityID, QScriptValue property, QScriptValue scopeOrCallback,
-        QScriptValue methodOrName = QScriptValue());
+    Q_INVOKABLE bool queryPropertyMetadata(const QUuid& entityID, const ScriptValue& property, const ScriptValue& scopeOrCallback,
+        const ScriptValue& methodOrName = ScriptValue());
 
 
     /*@jsdoc
@@ -1908,7 +1913,7 @@ public slots:
       *     {@link Graphics} API instead. 
       */
     // FIXME move to a renderable entity interface
-    Q_INVOKABLE void getMeshes(const QUuid& entityID, QScriptValue callback);
+    Q_INVOKABLE void getMeshes(const QUuid& entityID, const ScriptValue& callback);
 
     /*@jsdoc
      * Gets the object to world transform, excluding scale, of an entity.
@@ -2529,15 +2534,21 @@ public slots:
     void webEventReceived(const EntityItemID& entityItemID, const QVariant& message);
 
 protected:
-    void withEntitiesScriptEngine(std::function<void(QSharedPointer<EntitiesScriptEngineProvider>)> function, const EntityItemID& id) {
+    void withEntitiesScriptEngine(std::function<void(std::shared_ptr<EntitiesScriptEngineProvider>)> function, const EntityItemID& id) {
         auto entity = getEntityTree()->findEntityByEntityItemID(id);
         if (entity) {
             std::lock_guard<std::recursive_mutex> lock(_entitiesScriptEngineLock);
-            function((entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptEngine : _nonPersistentEntitiesScriptEngine);
+            function((entity->isLocalEntity() || entity->isMyAvatarEntity()) ? _persistentEntitiesScriptManager : _nonPersistentEntitiesScriptManager);
         }
     };
 
+private:
+    void attachDefaultEventHandlers(ScriptManager* manager);  // called on first call to Script.addEventHandler
+    friend void staticEntityScriptInitializer(ScriptManager* manager);
+
 private slots:
+    void releaseEntityPacketSenderMessages(bool wait);
+
     void handleEntityScriptCallMethodPacket(QSharedPointer<ReceivedMessage> receivedMessage, SharedNodePointer senderNode);
     void onAddingEntity(EntityItem* entity);
     void onDeletingEntity(EntityItem* entity);
@@ -2564,8 +2575,8 @@ private slots:
     EntityTreePointer _entityTree;
 
     std::recursive_mutex _entitiesScriptEngineLock;
-    QSharedPointer<EntitiesScriptEngineProvider> _persistentEntitiesScriptEngine;
-    QSharedPointer<EntitiesScriptEngineProvider> _nonPersistentEntitiesScriptEngine;
+    std::shared_ptr<EntitiesScriptEngineProvider> _persistentEntitiesScriptManager;
+    std::shared_ptr<EntitiesScriptEngineProvider> _nonPersistentEntitiesScriptManager;
 
     bool _bidOnSimulationOwnership { false };
 
diff --git a/libraries/entities/src/EntityTree.cpp b/libraries/entities/src/EntityTree.cpp
index 1c544f24f06..0bb59095a59 100644
--- a/libraries/entities/src/EntityTree.cpp
+++ b/libraries/entities/src/EntityTree.cpp
@@ -23,8 +23,6 @@
 #include <QJsonDocument>
 #include <QJsonArray>
 
-#include <QtScript/QScriptEngine>
-
 #include <Extents.h>
 #include <PerfStat.h>
 #include <Profile.h>
@@ -2944,8 +2942,8 @@ bool EntityTree::writeToMap(QVariantMap& entityDescription, OctreeElementPointer
     }
     entityDescription["DataVersion"] = _persistDataVersion;
     entityDescription["Id"] = _persistID;
-    QScriptEngine scriptEngine;
-    RecurseOctreeToMapOperator theOperator(entityDescription, element, &scriptEngine, skipDefaultValues,
+    ScriptEnginePointer engine = newScriptEngine();
+    RecurseOctreeToMapOperator theOperator(entityDescription, element, engine.get(), skipDefaultValues,
                                             skipThoseWithBadParents, _myAvatar);
     withReadLock([&] {
         recurseTreeWithOperator(&theOperator);
@@ -3091,10 +3089,10 @@ bool EntityTree::readFromMap(QVariantMap& map, const bool isImport) {
 
     // map will have a top-level list keyed as "Entities".  This will be extracted
     // and iterated over.  Each member of this list is converted to a QVariantMap, then
-    // to a QScriptValue, and then to EntityItemProperties.  These properties are used
+    // to a ScriptValue, and then to EntityItemProperties.  These properties are used
     // to add the new entity to the EntityTree.
     QVariantList entitiesQList = map["Entities"].toList();
-    QScriptEngine scriptEngine;
+    ScriptEnginePointer scriptEngine = newScriptEngine();
 
     if (entitiesQList.length() == 0) {
         // Empty map or invalidly formed file.
@@ -3105,7 +3103,7 @@ bool EntityTree::readFromMap(QVariantMap& map, const bool isImport) {
 
     bool success = true;
     foreach (QVariant entityVariant, entitiesQList) {
-        // QVariantMap --> QScriptValue --> EntityItemProperties --> Entity
+        // QVariantMap --> ScriptValue --> EntityItemProperties --> Entity
         QVariantMap entityMap = entityVariant.toMap();
 
         // handle parentJointName for wearables
@@ -3118,7 +3116,7 @@ bool EntityTree::readFromMap(QVariantMap& map, const bool isImport) {
                 " mapped it to parentJointIndex " << entityMap["parentJointIndex"].toInt();
         }
 
-        QScriptValue entityScriptValue = variantMapToScriptValue(entityMap, scriptEngine);
+        ScriptValue entityScriptValue = variantMapToScriptValue(entityMap, *scriptEngine);
         EntityItemProperties properties;
         EntityItemPropertiesFromScriptValueIgnoreReadOnly(entityScriptValue, properties);
 
@@ -3269,8 +3267,8 @@ bool EntityTree::readFromMap(QVariantMap& map, const bool isImport) {
 }
 
 bool EntityTree::writeToJSON(QString& jsonString, const OctreeElementPointer& element) {
-    QScriptEngine scriptEngine;
-    RecurseOctreeToJSONOperator theOperator(element, &scriptEngine, jsonString);
+    ScriptEnginePointer engine = newScriptEngine();
+    RecurseOctreeToJSONOperator theOperator(element, engine.get(), jsonString);
     withReadLock([&] {
         recurseTreeWithOperator(&theOperator);
     });
diff --git a/libraries/entities/src/GrabPropertyGroup.cpp b/libraries/entities/src/GrabPropertyGroup.cpp
index 7a9ba147d9b..10572dbcb8a 100644
--- a/libraries/entities/src/GrabPropertyGroup.cpp
+++ b/libraries/entities/src/GrabPropertyGroup.cpp
@@ -16,8 +16,8 @@
 #include "EntityItemProperties.h"
 #include "EntityItemPropertiesMacros.h"
 
-void GrabPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                          QScriptEngine* engine, bool skipDefaults,
+void GrabPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                          ScriptEngine* engine, bool skipDefaults,
                                           EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_GRAB_GRABBABLE, Grab, grab, Grabbable, grabbable);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_GRAB_KINEMATIC, Grab, grab, GrabKinematic, grabKinematic);
@@ -43,7 +43,7 @@ void GrabPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProp
 
 }
 
-void GrabPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void GrabPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(grab, grabbable, bool, setGrabbable);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(grab, grabKinematic, bool, setGrabKinematic);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(grab, grabFollowsController, bool, setGrabFollowsController);
diff --git a/libraries/entities/src/GrabPropertyGroup.h b/libraries/entities/src/GrabPropertyGroup.h
index 6f0bc9d48b2..ebf0175ea33 100644
--- a/libraries/entities/src/GrabPropertyGroup.h
+++ b/libraries/entities/src/GrabPropertyGroup.h
@@ -16,8 +16,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
-
 #include "PropertyGroup.h"
 #include "EntityItemPropertiesMacros.h"
 
@@ -25,6 +23,7 @@ class EntityItemProperties;
 class EncodeBitstreamParams;
 class OctreePacketData;
 class ReadBitstreamToTreeParams;
+class ScriptValue;
 
 static const bool INITIAL_GRABBABLE { true };
 static const bool INITIAL_KINEMATIC { true };
@@ -72,10 +71,10 @@ static const glm::vec3 INITIAL_EQUIPPABLE_INDICATOR_OFFSET { glm::vec3(0.0f) };
 class GrabPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const GrabPropertyGroup& other);
 
diff --git a/libraries/entities/src/HazePropertyGroup.cpp b/libraries/entities/src/HazePropertyGroup.cpp
index 632f73ced6e..04595789e59 100644
--- a/libraries/entities/src/HazePropertyGroup.cpp
+++ b/libraries/entities/src/HazePropertyGroup.cpp
@@ -16,7 +16,7 @@
 #include "EntityItemProperties.h"
 #include "EntityItemPropertiesMacros.h"
 
-void HazePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void HazePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_HAZE_RANGE, Haze, haze, HazeRange, hazeRange);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(PROP_HAZE_COLOR, Haze, haze, HazeColor, hazeColor, u8vec3Color);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(PROP_HAZE_GLARE_COLOR, Haze, haze, HazeGlareColor, hazeGlareColor, u8vec3Color);
@@ -34,7 +34,7 @@ void HazePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProp
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_HAZE_KEYLIGHT_ALTITUDE, Haze, haze, HazeKeyLightAltitude, hazeKeyLightAltitude);
 }
 
-void HazePropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void HazePropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(haze, hazeRange, float, setHazeRange);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(haze, hazeColor, u8vec3Color, setHazeColor);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(haze, hazeGlareColor, u8vec3Color, setHazeGlareColor);
diff --git a/libraries/entities/src/HazePropertyGroup.h b/libraries/entities/src/HazePropertyGroup.h
index 2828692a783..249d4c65bce 100644
--- a/libraries/entities/src/HazePropertyGroup.h
+++ b/libraries/entities/src/HazePropertyGroup.h
@@ -16,8 +16,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
-
 #include "PropertyGroup.h"
 #include "EntityItemPropertiesMacros.h"
 
@@ -26,6 +24,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 static const float INITIAL_HAZE_RANGE{ 1000.0f };
 static const glm::u8vec3 initialHazeGlareColor { 255, 229, 179 };
@@ -76,10 +76,10 @@ static const float INITIAL_KEY_LIGHT_ALTITUDE{ 200.0f };
 class HazePropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const HazePropertyGroup& other);
 
diff --git a/libraries/entities/src/KeyLightPropertyGroup.cpp b/libraries/entities/src/KeyLightPropertyGroup.cpp
index b70e94504df..b96f34d07c0 100644
--- a/libraries/entities/src/KeyLightPropertyGroup.cpp
+++ b/libraries/entities/src/KeyLightPropertyGroup.cpp
@@ -25,8 +25,8 @@ const bool KeyLightPropertyGroup::DEFAULT_KEYLIGHT_CAST_SHADOWS { false };
 const float KeyLightPropertyGroup::DEFAULT_KEYLIGHT_SHADOW_BIAS { 0.5f };
 const float KeyLightPropertyGroup::DEFAULT_KEYLIGHT_SHADOW_MAX_DISTANCE { 40.0f };
 
-void KeyLightPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, 
-    QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void KeyLightPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, 
+    ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
         
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(PROP_KEYLIGHT_COLOR, KeyLight, keyLight, Color, color, u8vec3Color);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_KEYLIGHT_INTENSITY, KeyLight, keyLight, Intensity, intensity);
@@ -36,7 +36,7 @@ void KeyLightPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desired
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_KEYLIGHT_SHADOW_MAX_DISTANCE, KeyLight, keyLight, ShadowMaxDistance, shadowMaxDistance);
 }
 
-void KeyLightPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void KeyLightPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(keyLight, color, u8vec3Color, setColor);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(keyLight, intensity, float, setIntensity);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(keyLight, direction, vec3, setDirection);
diff --git a/libraries/entities/src/KeyLightPropertyGroup.h b/libraries/entities/src/KeyLightPropertyGroup.h
index f65c6b6fb9e..b04f76a0980 100644
--- a/libraries/entities/src/KeyLightPropertyGroup.h
+++ b/libraries/entities/src/KeyLightPropertyGroup.h
@@ -17,7 +17,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
 #include "EntityItemPropertiesMacros.h"
 #include "PropertyGroup.h"
 
@@ -26,6 +25,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 /*@jsdoc
  * A key light is defined by the following properties:
@@ -45,10 +46,10 @@ class ReadBitstreamToTreeParams;
 class KeyLightPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const KeyLightPropertyGroup& other);
 
diff --git a/libraries/entities/src/PropertyGroup.h b/libraries/entities/src/PropertyGroup.h
index 8a9d7e9158c..68f3bfb5698 100644
--- a/libraries/entities/src/PropertyGroup.h
+++ b/libraries/entities/src/PropertyGroup.h
@@ -12,8 +12,6 @@
 #ifndef hifi_PropertyGroup_h
 #define hifi_PropertyGroup_h
 
-#include <QtScript/QScriptEngine>
-
 #include <OctreeElement.h>
 
 #include "EntityPropertyFlags.h"
@@ -24,6 +22,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 using EntityTreeElementExtraEncodeDataPointer = std::shared_ptr<EntityTreeElementExtraEncodeData>;
 
 
@@ -32,8 +32,8 @@ class PropertyGroup {
     virtual ~PropertyGroup() = default;
 
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const = 0;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) = 0;
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const = 0;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) = 0;
     virtual void debugDump() const { }
     virtual void listChangedProperties(QList<QString>& out) { }
 
diff --git a/libraries/entities/src/PulsePropertyGroup.cpp b/libraries/entities/src/PulsePropertyGroup.cpp
index 54f81750da9..b5ebd0cb2e8 100644
--- a/libraries/entities/src/PulsePropertyGroup.cpp
+++ b/libraries/entities/src/PulsePropertyGroup.cpp
@@ -57,8 +57,8 @@ void PulsePropertyGroup::setAlphaModeFromString(const QString& pulseMode) {
     }
 }
 
-void PulsePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                          QScriptEngine* engine, bool skipDefaults,
+void PulsePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                          ScriptEngine* engine, bool skipDefaults,
                                           EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_PULSE_MIN, Pulse, pulse, Min, min);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_PULSE_MAX, Pulse, pulse, Max, max);
@@ -67,7 +67,7 @@ void PulsePropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredPro
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_GETTER(PROP_PULSE_ALPHA_MODE, Pulse, pulse, AlphaMode, alphaMode, getAlphaModeAsString);
 }
 
-void PulsePropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void PulsePropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(pulse, min, float, setMin);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(pulse, max, float, setMax);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(pulse, period, float, setPeriod);
diff --git a/libraries/entities/src/PulsePropertyGroup.h b/libraries/entities/src/PulsePropertyGroup.h
index 665713d1281..58452fdeead 100644
--- a/libraries/entities/src/PulsePropertyGroup.h
+++ b/libraries/entities/src/PulsePropertyGroup.h
@@ -13,8 +13,6 @@
 
 #include <stdint.h>
 
-#include <QtScript/QScriptEngine>
-
 #include <PulseMode.h>
 
 #include "PropertyGroup.h"
@@ -24,6 +22,8 @@ class EntityItemProperties;
 class EncodeBitstreamParams;
 class OctreePacketData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 /*@jsdoc
  * A color and alpha pulse that an entity may have.
@@ -40,10 +40,10 @@ class ReadBitstreamToTreeParams;
 class PulsePropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const PulsePropertyGroup& other);
 
diff --git a/libraries/entities/src/RecurseOctreeToJSONOperator.cpp b/libraries/entities/src/RecurseOctreeToJSONOperator.cpp
index b64a700abcc..855085cbca4 100644
--- a/libraries/entities/src/RecurseOctreeToJSONOperator.cpp
+++ b/libraries/entities/src/RecurseOctreeToJSONOperator.cpp
@@ -11,8 +11,9 @@
 
 #include "RecurseOctreeToJSONOperator.h"
 #include "EntityItemProperties.h"
+#include <ScriptValue.h>
 
-RecurseOctreeToJSONOperator::RecurseOctreeToJSONOperator(const OctreeElementPointer&, QScriptEngine* engine,
+RecurseOctreeToJSONOperator::RecurseOctreeToJSONOperator(const OctreeElementPointer&, ScriptEngine* engine,
     QString jsonPrefix, bool skipDefaults, bool skipThoseWithBadParents):
     _engine(engine),
     _json(jsonPrefix),
@@ -34,7 +35,7 @@ void RecurseOctreeToJSONOperator::processEntity(const EntityItemPointer& entity)
         return;  // we weren't able to resolve a parent from _parentID, so don't save this entity.
     }
 
-    QScriptValue qScriptValues = _skipDefaults
+    ScriptValue qScriptValues = _skipDefaults
         ? EntityItemNonDefaultPropertiesToScriptValue(_engine, entity->getProperties())
         : EntityItemPropertiesToScriptValue(_engine, entity->getProperties());
 
diff --git a/libraries/entities/src/RecurseOctreeToJSONOperator.h b/libraries/entities/src/RecurseOctreeToJSONOperator.h
index a1d388ed222..09d383d5a72 100644
--- a/libraries/entities/src/RecurseOctreeToJSONOperator.h
+++ b/libraries/entities/src/RecurseOctreeToJSONOperator.h
@@ -11,9 +11,13 @@
 
 #include "EntityTree.h"
 
+#include <ScriptValue.h>
+
+class ScriptEngine;
+
 class RecurseOctreeToJSONOperator : public RecurseOctreeOperator {
 public:
-    RecurseOctreeToJSONOperator(const OctreeElementPointer&, QScriptEngine* engine, QString jsonPrefix = QString(), bool skipDefaults = true,
+    RecurseOctreeToJSONOperator(const OctreeElementPointer&, ScriptEngine* engine, QString jsonPrefix = QString(), bool skipDefaults = true,
         bool skipThoseWithBadParents = false);
     virtual bool preRecursion(const OctreeElementPointer& element) override { return true; };
     virtual bool postRecursion(const OctreeElementPointer& element) override;
@@ -23,8 +27,8 @@ class RecurseOctreeToJSONOperator : public RecurseOctreeOperator {
 private:
     void processEntity(const EntityItemPointer& entity);
 
-    QScriptEngine* _engine;
-    QScriptValue _toStringMethod;
+    ScriptEngine* _engine;
+    ScriptValue _toStringMethod;
 
     QString _json;
     const bool _skipDefaults;
diff --git a/libraries/entities/src/RecurseOctreeToMapOperator.cpp b/libraries/entities/src/RecurseOctreeToMapOperator.cpp
index 5be921112fc..deac281d49b 100644
--- a/libraries/entities/src/RecurseOctreeToMapOperator.cpp
+++ b/libraries/entities/src/RecurseOctreeToMapOperator.cpp
@@ -12,10 +12,11 @@
 #include "RecurseOctreeToMapOperator.h"
 
 #include "EntityItemProperties.h"
+#include <ScriptValue.h>
 
 RecurseOctreeToMapOperator::RecurseOctreeToMapOperator(QVariantMap& map,
                                                        const OctreeElementPointer& top,
-                                                       QScriptEngine* engine,
+                                                       ScriptEngine* engine,
                                                        bool skipDefaultValues,
                                                        bool skipThoseWithBadParents,
                                                        std::shared_ptr<AvatarData> myAvatar) :
@@ -56,7 +57,7 @@ bool RecurseOctreeToMapOperator::postRecursion(const OctreeElementPointer& eleme
         }
 
         EntityItemProperties properties = entityItem->getProperties();
-        QScriptValue qScriptValues;
+        ScriptValue qScriptValues;
         if (_skipDefaultValues) {
             qScriptValues = EntityItemNonDefaultPropertiesToScriptValue(_engine, properties);
         } else {
diff --git a/libraries/entities/src/RecurseOctreeToMapOperator.h b/libraries/entities/src/RecurseOctreeToMapOperator.h
index 985ec9de35c..9fbd9f41b29 100644
--- a/libraries/entities/src/RecurseOctreeToMapOperator.h
+++ b/libraries/entities/src/RecurseOctreeToMapOperator.h
@@ -11,16 +11,18 @@
 
 #include "EntityTree.h"
 
+class ScriptEngine;
+
 class RecurseOctreeToMapOperator : public RecurseOctreeOperator {
 public:
-    RecurseOctreeToMapOperator(QVariantMap& map, const OctreeElementPointer& top, QScriptEngine* engine, bool skipDefaultValues,
+    RecurseOctreeToMapOperator(QVariantMap& map, const OctreeElementPointer& top, ScriptEngine* engine, bool skipDefaultValues,
                                bool skipThoseWithBadParents, std::shared_ptr<AvatarData> myAvatar);
     bool preRecursion(const OctreeElementPointer& element) override;
     bool postRecursion(const OctreeElementPointer& element) override;
  private:
     QVariantMap& _map;
     OctreeElementPointer _top;
-    QScriptEngine* _engine;
+    ScriptEngine* _engine;
     bool _withinTop;
     bool _skipDefaultValues;
     bool _skipThoseWithBadParents;
diff --git a/libraries/entities/src/RingGizmoPropertyGroup.cpp b/libraries/entities/src/RingGizmoPropertyGroup.cpp
index 387cb1d688e..b9bb3a2b7e7 100644
--- a/libraries/entities/src/RingGizmoPropertyGroup.cpp
+++ b/libraries/entities/src/RingGizmoPropertyGroup.cpp
@@ -20,8 +20,8 @@ const float RingGizmoPropertyGroup::MAX_ALPHA = 1.0f;
 const float RingGizmoPropertyGroup::MIN_RADIUS = 0.0f;
 const float RingGizmoPropertyGroup::MAX_RADIUS = 0.5f;
 
-void RingGizmoPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                          QScriptEngine* engine, bool skipDefaults,
+void RingGizmoPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                          ScriptEngine* engine, bool skipDefaults,
                                           EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_START_ANGLE, Ring, ring, StartAngle, startAngle);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_END_ANGLE, Ring, ring, EndAngle, endAngle);
@@ -46,7 +46,7 @@ void RingGizmoPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desire
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(PROP_MINOR_TICK_MARKS_COLOR, Ring, ring, MinorTickMarksColor, minorTickMarksColor, u8vec3Color);
 }
 
-void RingGizmoPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void RingGizmoPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(ring, startAngle, float, setStartAngle);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(ring, endAngle, float, setEndAngle);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(ring, innerRadius, float, setInnerRadius);
diff --git a/libraries/entities/src/RingGizmoPropertyGroup.h b/libraries/entities/src/RingGizmoPropertyGroup.h
index 1d315622eb9..d34f01c9b06 100644
--- a/libraries/entities/src/RingGizmoPropertyGroup.h
+++ b/libraries/entities/src/RingGizmoPropertyGroup.h
@@ -11,8 +11,6 @@
 
 #include <stdint.h>
 
-#include <QtScript/QScriptEngine>
-
 #include "PropertyGroup.h"
 #include "EntityItemPropertiesMacros.h"
 #include "EntityItemPropertiesDefaults.h"
@@ -21,6 +19,8 @@ class EntityItemProperties;
 class EncodeBitstreamParams;
 class OctreePacketData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 using u8vec3Color = glm::u8vec3;
 
@@ -56,10 +56,10 @@ using u8vec3Color = glm::u8vec3;
 class RingGizmoPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const RingGizmoPropertyGroup& other);
 
diff --git a/libraries/entities/src/SkyboxPropertyGroup.cpp b/libraries/entities/src/SkyboxPropertyGroup.cpp
index 89ffa95dbe9..43ffc878f4c 100644
--- a/libraries/entities/src/SkyboxPropertyGroup.cpp
+++ b/libraries/entities/src/SkyboxPropertyGroup.cpp
@@ -18,12 +18,12 @@
 
 const glm::u8vec3 SkyboxPropertyGroup::DEFAULT_COLOR = { 0, 0, 0 };
 
-void SkyboxPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties, QScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
+void SkyboxPropertyGroup::copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties, ScriptEngine* engine, bool skipDefaults, EntityItemProperties& defaultEntityProperties) const {
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE_TYPED(PROP_SKYBOX_COLOR, Skybox, skybox, Color, color, u8vec3Color);
     COPY_GROUP_PROPERTY_TO_QSCRIPTVALUE(PROP_SKYBOX_URL, Skybox, skybox, URL, url);
 }
 
-void SkyboxPropertyGroup::copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) {
+void SkyboxPropertyGroup::copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) {
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(skybox, color, u8vec3Color, setColor);
     COPY_GROUP_PROPERTY_FROM_QSCRIPTVALUE(skybox, url, QString, setURL);
 }
diff --git a/libraries/entities/src/SkyboxPropertyGroup.h b/libraries/entities/src/SkyboxPropertyGroup.h
index 36cea0a52a4..89b2016802c 100644
--- a/libraries/entities/src/SkyboxPropertyGroup.h
+++ b/libraries/entities/src/SkyboxPropertyGroup.h
@@ -16,8 +16,6 @@
 
 #include <glm/glm.hpp>
 
-#include <QtScript/QScriptEngine>
-
 #include <ColorUtils.h>
 
 #include "PropertyGroup.h"
@@ -28,6 +26,8 @@ class EncodeBitstreamParams;
 class OctreePacketData;
 class EntityTreeElementExtraEncodeData;
 class ReadBitstreamToTreeParams;
+class ScriptEngine;
+class ScriptValue;
 
 /*@jsdoc
  * A skybox is defined by the following properties:
@@ -39,10 +39,10 @@ class ReadBitstreamToTreeParams;
 class SkyboxPropertyGroup : public PropertyGroup {
 public:
     // EntityItemProperty related helpers
-    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, QScriptValue& properties,
-                                   QScriptEngine* engine, bool skipDefaults,
+    virtual void copyToScriptValue(const EntityPropertyFlags& desiredProperties, ScriptValue& properties,
+                                   ScriptEngine* engine, bool skipDefaults,
                                    EntityItemProperties& defaultEntityProperties) const override;
-    virtual void copyFromScriptValue(const QScriptValue& object, bool& _defaultSettings) override;
+    virtual void copyFromScriptValue(const ScriptValue& object, bool& _defaultSettings) override;
 
     void merge(const SkyboxPropertyGroup& other);
 
diff --git a/libraries/graphics-scripting/src/graphics-scripting/Forward.h b/libraries/graphics-scripting/src/graphics-scripting/Forward.h
index 8804b63de9c..6acce99af54 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/Forward.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/Forward.h
@@ -22,7 +22,6 @@ using ModelPointer = std::shared_ptr<Model>;
 namespace gpu {
     class BufferView;
 }
-class QScriptEngine;
 
 namespace scriptable {
     using Mesh = graphics::Mesh;
diff --git a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.cpp b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.cpp
index 12c07d336d3..aa59a8f445d 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.cpp
+++ b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.cpp
@@ -17,15 +17,16 @@
 #include "ScriptableMeshPart.h"
 #include <GeometryUtil.h>
 #include <QUuid>
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptValueIterator>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptValue.h>
+#include <ScriptValueUtils.h>
 #include <graphics/BufferViewHelpers.h>
 #include <graphics/GpuHelpers.h>
 #include <shared/QtHelpers.h>
 #include <SpatiallyNestable.h>
 
-GraphicsScriptingInterface::GraphicsScriptingInterface(QObject* parent) : QObject(parent), QScriptable() {
+GraphicsScriptingInterface::GraphicsScriptingInterface(QObject* parent) : QObject(parent), Scriptable() {
 }
 
 void GraphicsScriptingInterface::jsThrowError(const QString& error) {
@@ -314,24 +315,24 @@ namespace {
 }
 
 namespace scriptable {
-    template <typename T> int registerQPointerMetaType(QScriptEngine* engine) {
-        qScriptRegisterSequenceMetaType<QVector<QPointer<T>>>(engine);
-        return qScriptRegisterMetaType<QPointer<T>>(
+    template <typename T> int registerQPointerMetaType(ScriptEngine* engine) {
+        scriptRegisterSequenceMetaType<QVector<QPointer<T>>>(engine);
+        return scriptRegisterMetaType<QPointer<T>>(
             engine,
-            [](QScriptEngine* engine, const QPointer<T>& object) -> QScriptValue {
+            [](ScriptEngine* engine, const QPointer<T>& object) -> ScriptValue {
                 if (!object) {
-                    return QScriptValue::NullValue;
+                    return engine->nullValue();
                 }
-                return engine->newQObject(object, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater | QScriptEngine::AutoCreateDynamicProperties);
+                return engine->newQObject(object, ScriptEngine::QtOwnership, ScriptEngine::AutoCreateDynamicProperties);
             },
-            [](const QScriptValue& value, QPointer<T>& out) {
+            [](const ScriptValue& value, QPointer<T>& out) -> bool {
                 auto obj = value.toQObject();
 #ifdef SCRIPTABLE_MESH_DEBUG
                 qCInfo(graphics_scripting) << "qpointer_qobject_cast" << obj << value.toString();
 #endif
                 if (auto tmp = qobject_cast<T*>(obj)) {
                     out = QPointer<T>(tmp);
-                    return;
+                    return true;
                 }
 #if 0
                 if (auto tmp = static_cast<T*>(obj)) {
@@ -339,20 +340,22 @@ namespace scriptable {
                     qCInfo(graphics_scripting) << "qpointer_qobject_cast -- via static_cast" << obj << tmp << value.toString();
 #endif
                     out = QPointer<T>(tmp);
-                    return;
+                    return true;
                 }
 #endif
                 out = nullptr;
+                return false;
             }
         );
     }
 
-    QScriptValue qVectorScriptableMaterialLayerToScriptValue(QScriptEngine* engine, const QVector<scriptable::ScriptableMaterialLayer>& vector) {
-        return qScriptValueFromSequence(engine, vector);
+    ScriptValue qVectorScriptableMaterialLayerToScriptValue(ScriptEngine* engine, const QVector<scriptable::ScriptableMaterialLayer>& vector) {
+        return scriptValueFromSequence(engine, vector);
     }
 
-    void qVectorScriptableMaterialLayerFromScriptValue(const QScriptValue& array, QVector<scriptable::ScriptableMaterialLayer>& result) {
-        qScriptValueToSequence(array, result);
+    bool qVectorScriptableMaterialLayerFromScriptValue(const ScriptValue& array, QVector<scriptable::ScriptableMaterialLayer>& result) {
+        scriptValueToSequence(array, result);
+        return true;
     }
 
     /*@jsdoc
@@ -469,14 +472,14 @@ namespace scriptable {
      * @property {boolean} defaultFallthrough - <code>true</code> if all properties fall through to the material below unless 
      *     they are set, <code>false</code> if properties respect their individual fall-through settings.
      */
-    QScriptValue scriptableMaterialToScriptValue(QScriptEngine* engine, const scriptable::ScriptableMaterial &material) {
-        QScriptValue obj = engine->newObject();
+    ScriptValue scriptableMaterialToScriptValue(ScriptEngine* engine, const scriptable::ScriptableMaterial &material) {
+        ScriptValue obj = engine->newObject();
         obj.setProperty("name", material.name);
         obj.setProperty("model", material.model);
 
         bool hasPropertyFallthroughs = !material.propertyFallthroughs.empty();
 
-        const QScriptValue FALLTHROUGH("fallthrough");
+        const ScriptValue FALLTHROUGH(engine->newValue("fallthrough"));
         if (hasPropertyFallthroughs && material.propertyFallthroughs.at(graphics::MaterialKey::OPACITY_VAL_BIT)) {
             obj.setProperty("opacity", FALLTHROUGH);
         } else if (material.key.isTranslucentFactor()) {
@@ -624,49 +627,53 @@ namespace scriptable {
         return obj;
     }
 
-    void scriptableMaterialFromScriptValue(const QScriptValue &object, scriptable::ScriptableMaterial& material) {
-        // No need to convert from QScriptValue to ScriptableMaterial
+    bool scriptableMaterialFromScriptValue(const ScriptValue& object, scriptable::ScriptableMaterial& material) {
+        // No need to convert from ScriptValue to ScriptableMaterial
+        return false;
     }
 
-    QScriptValue scriptableMaterialLayerToScriptValue(QScriptEngine* engine, const scriptable::ScriptableMaterialLayer &materialLayer) {
-        QScriptValue obj = engine->newObject();
+    ScriptValue scriptableMaterialLayerToScriptValue(ScriptEngine* engine, const scriptable::ScriptableMaterialLayer &materialLayer) {
+        ScriptValue obj = engine->newObject();
         obj.setProperty("material", scriptableMaterialToScriptValue(engine, materialLayer.material));
         obj.setProperty("priority", materialLayer.priority);
         return obj;
     }
 
-    void scriptableMaterialLayerFromScriptValue(const QScriptValue &object, scriptable::ScriptableMaterialLayer& materialLayer) {
-        // No need to convert from QScriptValue to ScriptableMaterialLayer
+    bool scriptableMaterialLayerFromScriptValue(const ScriptValue& object, scriptable::ScriptableMaterialLayer& materialLayer) {
+        // No need to convert from ScriptValue to ScriptableMaterialLayer
+        return false;
     }
 
-    QScriptValue multiMaterialMapToScriptValue(QScriptEngine* engine, const scriptable::MultiMaterialMap& map) {
-        QScriptValue obj = engine->newObject();
+    ScriptValue multiMaterialMapToScriptValue(ScriptEngine* engine, const scriptable::MultiMaterialMap& map) {
+        ScriptValue obj = engine->newObject();
         for (auto key : map.keys()) {
             obj.setProperty(key, qVectorScriptableMaterialLayerToScriptValue(engine, map[key]));
         }
         return obj;
     }
 
-    void multiMaterialMapFromScriptValue(const QScriptValue& map, scriptable::MultiMaterialMap& result) {
-        // No need to convert from QScriptValue to MultiMaterialMap
+    bool multiMaterialMapFromScriptValue(const ScriptValue& map, scriptable::MultiMaterialMap& result) {
+        // No need to convert from ScriptValue to MultiMaterialMap
+        return false;
     }
 
-    template <typename T> int registerDebugEnum(QScriptEngine* engine, const DebugEnums<T>& debugEnums) {
+    template <typename T> int registerDebugEnum(ScriptEngine* engine, const DebugEnums<T>& debugEnums) {
         static const DebugEnums<T>& instance = debugEnums;
-        return qScriptRegisterMetaType<T>(
+        return scriptRegisterMetaType<T>(
             engine,
-            [](QScriptEngine* engine, const T& topology) -> QScriptValue {
-                return instance.value(topology);
+            [](ScriptEngine* engine, const T& topology) -> ScriptValue {
+                return engine->newValue(instance.value(topology));
             },
-            [](const QScriptValue& value, T& topology) {
+            [](const ScriptValue& value, T& topology) -> bool {
                 topology = instance.key(value.toString());
+                return true;
             }
         );
     }
 }
 
-void GraphicsScriptingInterface::registerMetaTypes(QScriptEngine* engine) {
-    qScriptRegisterSequenceMetaType<QVector<scriptable::ScriptableMaterialLayer>>(engine);
+void GraphicsScriptingInterface::registerMetaTypes(ScriptEngine* engine) {
+    scriptRegisterSequenceMetaType<QVector<scriptable::ScriptableMaterialLayer>>(engine);
 
     scriptable::registerQPointerMetaType<scriptable::ScriptableModel>(engine);
     scriptable::registerQPointerMetaType<scriptable::ScriptableMesh>(engine);
@@ -677,10 +684,10 @@ void GraphicsScriptingInterface::registerMetaTypes(QScriptEngine* engine) {
     scriptable::registerDebugEnum<gpu::Semantic>(engine, gpu::SEMANTICS);
     scriptable::registerDebugEnum<gpu::Dimension>(engine, gpu::DIMENSIONS);
 
-    qScriptRegisterMetaType(engine, scriptable::scriptableMaterialToScriptValue, scriptable::scriptableMaterialFromScriptValue);
-    qScriptRegisterMetaType(engine, scriptable::scriptableMaterialLayerToScriptValue, scriptable::scriptableMaterialLayerFromScriptValue);
-    qScriptRegisterMetaType(engine, scriptable::qVectorScriptableMaterialLayerToScriptValue, scriptable::qVectorScriptableMaterialLayerFromScriptValue);
-    qScriptRegisterMetaType(engine, scriptable::multiMaterialMapToScriptValue, scriptable::multiMaterialMapFromScriptValue);
+    scriptRegisterMetaType(engine, scriptable::scriptableMaterialToScriptValue, scriptable::scriptableMaterialFromScriptValue);
+    scriptRegisterMetaType(engine, scriptable::scriptableMaterialLayerToScriptValue, scriptable::scriptableMaterialLayerFromScriptValue);
+    scriptRegisterMetaType(engine, scriptable::qVectorScriptableMaterialLayerToScriptValue, scriptable::qVectorScriptableMaterialLayerFromScriptValue);
+    scriptRegisterMetaType(engine, scriptable::multiMaterialMapToScriptValue, scriptable::multiMaterialMapFromScriptValue);
 
     Q_UNUSED(metaTypeIds);
 }
diff --git a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.h b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.h
index beb5b340e88..a2ffb9184b7 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingInterface.h
@@ -14,13 +14,13 @@
 #include <QtCore/QObject>
 #include <QUrl>
 
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptable>
-
 #include "ScriptableMesh.h"
 #include <DependencyManager.h>
 #include "RegisteredMetaTypes.h"
+#include <Scriptable.h>
+#include <ScriptValue.h>
 
+class ScriptEngine;
 
 /*@jsdoc
  * The <code>Graphics</code> API enables you to access and manipulate avatar, entity, and overlay models in the rendered scene. 
@@ -34,11 +34,11 @@
  * @hifi-avatar
  */
 
-class GraphicsScriptingInterface : public QObject, public QScriptable, public Dependency {
+class GraphicsScriptingInterface : public QObject, public Scriptable, public Dependency {
     Q_OBJECT
 
 public:
-    static void registerMetaTypes(QScriptEngine* engine);
+    static void registerMetaTypes(ScriptEngine* engine);
     GraphicsScriptingInterface(QObject* parent = nullptr);
 
 public slots:
@@ -149,7 +149,7 @@ public slots:
 };
 
 namespace scriptable {
-    QScriptValue scriptableMaterialToScriptValue(QScriptEngine* engine, const scriptable::ScriptableMaterial &material);
+    ScriptValue scriptableMaterialToScriptValue(ScriptEngine* engine, const scriptable::ScriptableMaterial &material);
 };
 
 Q_DECLARE_METATYPE(NestableType)
diff --git a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.cpp b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.cpp
index 2db34258c97..9730fd0ec87 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.cpp
+++ b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.cpp
@@ -7,11 +7,12 @@
 
 #include "GraphicsScriptingUtil.h"
 
-#include <BaseScriptEngine.h>
-
 #include <graphics/BufferViewHelpers.h>
 #include <AABox.h>
 #include <Extents.h>
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
 
 using buffer_helpers::glmVecToVariant;
 
@@ -77,7 +78,7 @@ QVariant toVariant(const gpu::Element& element) {
      };
 }
 
-QScriptValue jsBindCallback(QScriptValue value) {
+ScriptValue jsBindCallback(const ScriptValue& value) {
     if (value.isObject() && value.property("callback").isFunction()) {
         // value is already a bound callback
         return value;
@@ -85,8 +86,8 @@ QScriptValue jsBindCallback(QScriptValue value) {
     auto engine = value.engine();
     auto context = engine ? engine->currentContext() : nullptr;
     auto length = context ? context->argumentCount() : 0;
-    QScriptValue scope = context ? context->thisObject() : QScriptValue::NullValue;
-    QScriptValue method;
+    ScriptValue scope = context ? context->thisObject() : engine->nullValue();
+    ScriptValue method;
 #ifdef SCRIPTABLE_MESH_DEBUG
     qCInfo(graphics_scripting) << "jsBindCallback" << engine << length << scope.toQObject() << method.toString();
 #endif
@@ -111,9 +112,9 @@ QScriptValue jsBindCallback(QScriptValue value) {
 }
 
 template <typename T>
-T this_qobject_cast(QScriptEngine* engine) {
+T this_qobject_cast(ScriptEngine* engine) {
     auto context = engine ? engine->currentContext() : nullptr;
-    return qscriptvalue_cast<T>(context ? context->thisObject() : QScriptValue::NullValue);
+    return scriptvalue_cast<T>(context ? context->thisObject() : engine ? engine->nullValue() : ScriptValue());
 }
 QString toDebugString(QObject* tmp) {
     QString s;
diff --git a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.h b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.h
index 1ca62277ff5..53b49d1bd34 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/GraphicsScriptingUtil.h
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValue>
 #include <QtCore/QPointer>
 #include <QtCore/QObject>
 #include <QtCore/QLoggingCategory>
@@ -9,6 +7,9 @@
 #include <memory>
 #include <functional>
 #include <glm/glm.hpp>
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class Extents;
 class AABox;
@@ -24,15 +25,15 @@ namespace scriptable {
     QVariant toVariant(const glm::mat4& mat4);
 
     // helper that automatically resolves Qt-signal-like scoped callbacks
-    // ... C++ side: `void MyClass::asyncMethod(..., QScriptValue callback)` 
+    // ... C++ side: `void MyClass::asyncMethod(..., const ScriptValue& callback)` 
     // ... JS side:
     //     * `API.asyncMethod(..., function(){})`
     //     * `API.asyncMethod(..., scope, function(){})`
     //     * `API.asyncMethod(..., scope, "methodName")`
-    QScriptValue jsBindCallback(QScriptValue callback);
+    ScriptValue jsBindCallback(const ScriptValue& callback);
 
     // cast engine->thisObject() => C++ class instance
-    template <typename T> T this_qobject_cast(QScriptEngine* engine);
+    template <typename T> T this_qobject_cast(ScriptEngine* engine);
 
     QString toDebugString(QObject* tmp);
     template <typename T> QString toDebugString(std::shared_ptr<T> tmp);
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.cpp b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.cpp
index f7d40f19f29..f19e58eca9d 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.cpp
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.cpp
@@ -7,17 +7,17 @@
 
 #include "ScriptableMesh.h"
 
-#include <QtScript/QScriptValue>
-
 #include <glm/glm.hpp>
 #include <glm/gtx/norm.hpp>
 #include <glm/gtx/transform.hpp>
 
-#include <BaseScriptEngine.h>
 #include <graphics/BufferViewHelpers.h>
 #include <graphics/GpuHelpers.h>
 #include <graphics/Geometry.h>
 #include <RegisteredMetaTypes.h>
+#include <ScriptEngine.h>
+#include <ScriptEngineCast.h>
+#include <ScriptValue.h>
 
 #include "Forward.h"
 #include "ScriptableMeshPart.h"
@@ -27,7 +27,7 @@
 // #define SCRIPTABLE_MESH_DEBUG 1
 
 scriptable::ScriptableMesh::ScriptableMesh(const ScriptableMeshBase& other)
-    : ScriptableMeshBase(other), QScriptable() {
+    : ScriptableMeshBase(other), Scriptable() {
     auto mesh = getMeshPointer();
     QString name = mesh ? QString::fromStdString(mesh->modelName) : "";
     if (name.isEmpty()) {
@@ -264,7 +264,7 @@ bool scriptable::ScriptableMesh::setVertexProperty(glm::uint32 vertexIndex, cons
  * @param {number} index - The vertex index.
  * @param {object} properties - The properties of the mesh, per {@link GraphicsMesh}.
  */
-glm::uint32 scriptable::ScriptableMesh::forEachVertex(QScriptValue _callback) {
+glm::uint32 scriptable::ScriptableMesh::forEachVertex(const ScriptValue& _callback) {
     auto mesh = getMeshPointer();
     if (!mesh) {
         return 0;
@@ -278,10 +278,10 @@ glm::uint32 scriptable::ScriptableMesh::forEachVertex(QScriptValue _callback) {
     if (!js) {
         return 0;
     }
-    auto meshPart = js ? js->toScriptValue(getSelf()) : QScriptValue::NullValue;
+    auto meshPart = js ? js->toScriptValue(getSelf()) : js->nullValue();
     int numProcessed = 0;
     buffer_helpers::mesh::forEachVertex(mesh, [&](glm::uint32 index, const QVariantMap& values) {
-        auto result = callback.call(scope, { js->toScriptValue(values), index, meshPart });
+        auto result = callback.call(scope, { js->toScriptValue(values), js->newValue(index), meshPart });
         if (js->hasUncaughtException()) {
             js->currentContext()->throwValue(js->uncaughtException());
             return false;
@@ -302,7 +302,7 @@ glm::uint32 scriptable::ScriptableMesh::forEachVertex(QScriptValue _callback) {
  * @returns {Object<Graphics.BufferTypeName, Graphics.BufferType>|boolean} The attribute values to update the vertex with, or 
  *     <code>false</code> to not update the vertex.
  */
-glm::uint32 scriptable::ScriptableMesh::updateVertexAttributes(QScriptValue _callback) {
+glm::uint32 scriptable::ScriptableMesh::updateVertexAttributes(const ScriptValue& _callback) {
     auto mesh = getMeshPointer();
     if (!mesh) {
         return 0;
@@ -316,12 +316,12 @@ glm::uint32 scriptable::ScriptableMesh::updateVertexAttributes(QScriptValue _cal
     if (!js) {
         return 0;
     }
-    auto meshPart = js ? js->toScriptValue(getSelf()) : QScriptValue::NullValue;
+    auto meshPart = js ? js->toScriptValue(getSelf()) : js->nullValue();
     int numProcessed = 0;
     auto attributeViews = buffer_helpers::mesh::getAllBufferViews(mesh);
     buffer_helpers::mesh::forEachVertex(mesh, [&](glm::uint32 index, const QVariantMap& values) {
         auto obj = js->toScriptValue(values);
-        auto result = callback.call(scope, { obj, index, meshPart });
+        auto result = callback.call(scope, { obj, js->newValue(index), meshPart });
         if (js->hasUncaughtException()) {
             js->currentContext()->throwValue(js->uncaughtException());
             return false;
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.h b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.h
index a6ebbe85363..4a1419dd45a 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMesh.h
@@ -20,12 +20,13 @@
 #include <QtCore/QUuid>
 #include <QtCore/QVariant>
 #include <QtCore/QVector>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptable>
 
 #include "GraphicsScriptingUtil.h"
 
 #include <graphics/Geometry.h>
+#include <Scriptable.h>
+
+class ScriptValue;
 
 namespace scriptable {
     /*@jsdoc
@@ -65,7 +66,7 @@ namespace scriptable {
      * @borrows GraphicsMesh.getVertextAttributes as getVertextAttributes
      * @borrows GraphicsMesh.setVertextAttributes as setVertextAttributes
      */
-    class ScriptableMesh : public ScriptableMeshBase, QScriptable {
+    class ScriptableMesh : public ScriptableMeshBase, Scriptable {
         Q_OBJECT
     public:
         Q_PROPERTY(glm::uint32 numParts READ getNumParts)
@@ -83,11 +84,11 @@ namespace scriptable {
         operator const ScriptableMeshBase*() const { return (qobject_cast<const scriptable::ScriptableMeshBase*>(this)); }
 
         ScriptableMesh(WeakModelProviderPointer provider, ScriptableModelBasePointer model, MeshPointer mesh, QObject* parent)
-            : ScriptableMeshBase(provider, model, mesh, parent), QScriptable() { strongMesh = mesh; }
+            : ScriptableMeshBase(provider, model, mesh, parent), Scriptable() { strongMesh = mesh; }
         ScriptableMesh(MeshPointer mesh, QObject* parent)
-            : ScriptableMeshBase(WeakModelProviderPointer(), nullptr, mesh, parent), QScriptable() { strongMesh = mesh; }
+            : ScriptableMeshBase(WeakModelProviderPointer(), nullptr, mesh, parent), Scriptable() { strongMesh = mesh; }
         ScriptableMesh(const ScriptableMeshBase& other);
-        ScriptableMesh(const ScriptableMesh& other) : ScriptableMeshBase(other), QScriptable() {};
+        ScriptableMesh(const ScriptableMesh& other) : ScriptableMeshBase(other), Scriptable() {};
         virtual ~ScriptableMesh();
 
         const scriptable::MeshPointer getOwnedMeshPointer() const { return strongMesh; }
@@ -224,7 +225,7 @@ namespace scriptable {
          */
         scriptable::ScriptableMeshPointer cloneMesh();
 
-        // QScriptEngine-specific wrappers
+        // ScriptEngine-specific wrappers
 
         /*@jsdoc
          * Updates vertex attributes by calling a function for each vertex. The function can return modified attributes to 
@@ -233,7 +234,7 @@ namespace scriptable {
          * @param {GraphicsMesh~updateVertexAttributesCallback} callback - The function to call for each vertex.
          * @returns {number} The number of vertices the callback was called for.
          */
-        glm::uint32 updateVertexAttributes(QScriptValue callback);
+        glm::uint32 updateVertexAttributes(const ScriptValue& callback);
 
         /*@jsdoc
          * Calls a function for each vertex.
@@ -241,7 +242,7 @@ namespace scriptable {
          * @param {GraphicsMesh~forEachVertexCallback} callback - The function to call for each vertex.
          * @returns {number} The number of vertices the callback was called for.
          */
-        glm::uint32 forEachVertex(QScriptValue callback);
+        glm::uint32 forEachVertex(const ScriptValue& callback);
 
         /*@jsdoc
          * Checks if an index is valid and, optionally, that vertex has a particular attribute.
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.cpp b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.cpp
index 9914aca1772..1b93705dc86 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.cpp
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.cpp
@@ -11,8 +11,7 @@
 #include <glm/gtx/norm.hpp>
 #include <glm/gtx/transform.hpp>
 
-#include <BaseScriptEngine.h>
-#include <QtScript/QScriptValue>
+#include <ScriptValue.h>
 #include <RegisteredMetaTypes.h>
 #include <graphics/BufferViewHelpers.h>
 #include <graphics/GpuHelpers.h>
@@ -78,12 +77,12 @@ QVariantList scriptable::ScriptableMeshPart::queryVertexAttributes(QVariant sele
     return parentMesh->queryVertexAttributes(selector);
 }
 
-glm::uint32 scriptable::ScriptableMeshPart::forEachVertex(QScriptValue _callback) {
+glm::uint32 scriptable::ScriptableMeshPart::forEachVertex(const ScriptValue& _callback) {
     // TODO: limit to vertices within the part's indexed range?
     return isValid() ? parentMesh->forEachVertex(_callback) : 0;
 }
 
-glm::uint32 scriptable::ScriptableMeshPart::updateVertexAttributes(QScriptValue _callback) {
+glm::uint32 scriptable::ScriptableMeshPart::updateVertexAttributes(const ScriptValue& _callback) {
     // TODO: limit to vertices within the part's indexed range?
     return isValid() ? parentMesh->updateVertexAttributes(_callback) : 0;
 }
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.h b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.h
index 716081a4b8c..009d7b257cf 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableMeshPart.h
@@ -8,6 +8,9 @@
 #pragma once
 
 #include "ScriptableMesh.h"
+#include <Scriptable.h>
+
+class ScriptValue;
 
 namespace scriptable {
     /*@jsdoc
@@ -55,7 +58,7 @@ namespace scriptable {
      * @borrows GraphicsMesh.getVertexAttributes as getVertextAttributes
      * @borrows GraphicsMesh.setVertexAttributes as setVertextAttributes
      */
-    class ScriptableMeshPart : public QObject, QScriptable {
+    class ScriptableMeshPart : public QObject, Scriptable {
         Q_OBJECT
         Q_PROPERTY(bool valid READ isValid)
         Q_PROPERTY(glm::uint32 partIndex MEMBER partIndex CONSTANT)
@@ -78,7 +81,7 @@ namespace scriptable {
     public:
         ScriptableMeshPart(scriptable::ScriptableMeshPointer parentMesh, int partIndex);
         ScriptableMeshPart& operator=(const ScriptableMeshPart& view) { parentMesh=view.parentMesh; return *this; };
-        ScriptableMeshPart(const ScriptableMeshPart& other) : QObject(other.parent()), QScriptable(), parentMesh(other.parentMesh), partIndex(other.partIndex) {}
+        ScriptableMeshPart(const ScriptableMeshPart& other) : QObject(other.parent()), Scriptable(), parentMesh(other.parentMesh), partIndex(other.partIndex) {}
         bool isValid() const { auto mesh = getMeshPointer(); return mesh && partIndex < mesh->getNumParts(); }
 
     public slots:
@@ -273,7 +276,7 @@ namespace scriptable {
         QString toOBJ();
 
 
-        // QScriptEngine-specific wrappers
+        // ScriptEngine-specific wrappers
 
         /*@jsdoc
          * Updates vertex attributes by calling a function for each vertex in the <em>whole</em> mesh (i.e., the parent and 
@@ -282,7 +285,7 @@ namespace scriptable {
          * @param {GraphicsMesh~updateVertexAttributesCallback} callback - The function to call for each vertex.
          * @returns {number} The number of vertices the callback was called for.
          */
-        glm::uint32 updateVertexAttributes(QScriptValue callback);
+        glm::uint32 updateVertexAttributes(const ScriptValue& callback);
 
         /*@jsdoc
          * Calls a function for each vertex in the <em>whole</em> mesh (i.e., parent and mesh parts).
@@ -290,7 +293,7 @@ namespace scriptable {
          * @param {GraphicsMesh~forEachVertexCallback} callback - The function to call for each vertex.
          * @returns {number} The number of vertices the callback was called for.
          */
-        glm::uint32 forEachVertex(QScriptValue callback);
+        glm::uint32 forEachVertex(const ScriptValue& callback);
 
         /*@jsdoc
          * Checks if an index is valid and, optionally, that vertex has a particular attribute.
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.cpp b/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.cpp
index 28cd49e7c47..ed61fa049f5 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.cpp
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.cpp
@@ -10,7 +10,7 @@
 
 #include "ScriptableModel.h"
 
-#include <QtScript/QScriptEngine>
+#include <ScriptValue.h>
 
 #include "GraphicsScriptingUtil.h"
 #include "ScriptableMesh.h"
@@ -262,7 +262,7 @@ scriptable::ScriptableMeshes scriptable::ScriptableModel::getMeshes() {
 }
 
 #if 0
-glm::uint32 scriptable::ScriptableModel::forEachVertexAttribute(QScriptValue callback) {
+glm::uint32 scriptable::ScriptableModel::forEachVertexAttribute(const ScriptValue& callback) {
     glm::uint32 result = 0;
     scriptable::ScriptableMeshes in = getMeshes();
     if (in.size()) {
diff --git a/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.h b/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.h
index 637b5378001..fb6f1dc0ca7 100644
--- a/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.h
+++ b/libraries/graphics-scripting/src/graphics-scripting/ScriptableModel.h
@@ -10,8 +10,6 @@
 #include "Forward.h"
 #include "GraphicsScriptingUtil.h"
 
-class QScriptValue;
-
 namespace scriptable {
 
     using ScriptableMeshes = QVector<scriptable::ScriptableMeshPointer>;
diff --git a/libraries/input-plugins/CMakeLists.txt b/libraries/input-plugins/CMakeLists.txt
index b1fcc4076a0..bc48c10b3a7 100644
--- a/libraries/input-plugins/CMakeLists.txt
+++ b/libraries/input-plugins/CMakeLists.txt
@@ -1,5 +1,6 @@
 set(TARGET_NAME input-plugins)
 setup_hifi_library()
 link_hifi_libraries(shared plugins ui-plugins controllers ui)
+include_hifi_library_headers(script-engine)
 
 GroupSources("src/input-plugins")
diff --git a/libraries/midi/CMakeLists.txt b/libraries/midi/CMakeLists.txt
index dc54819c2b9..66757566408 100644
--- a/libraries/midi/CMakeLists.txt
+++ b/libraries/midi/CMakeLists.txt
@@ -1,3 +1,8 @@
 set(TARGET_NAME midi)
 setup_hifi_library(Network)
 link_hifi_libraries(shared networking)
+include_hifi_library_headers(script-engine)
+
+if (WIN32)
+    target_link_libraries(${TARGET_NAME} winmm.lib)
+endif ()
diff --git a/libraries/midi/src/Midi.cpp b/libraries/midi/src/Midi.cpp
index 02d47198e96..8544a809810 100644
--- a/libraries/midi/src/Midi.cpp
+++ b/libraries/midi/src/Midi.cpp
@@ -15,11 +15,13 @@
 
 #include <QtCore/QLoggingCategory>
 
-#if defined Q_OS_WIN32
-#include "Windows.h"
-#endif
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
 
 #if defined Q_OS_WIN32
+#include <Windows.h>
+#include <mmeapi.h>
+
 const int MIDI_BYTE_MASK = 0x0FF;
 const int MIDI_NIBBLE_MASK = 0x00F;
 const int MIDI_PITCH_BEND_MASK = 0x3F80;
@@ -131,6 +133,12 @@ void CALLBACK MidiInProc(HMIDIIN hMidiIn, UINT wMsg, DWORD_PTR dwInstance, DWORD
     }
 }
 
+STATIC_SCRIPT_INITIALIZER(+[](ScriptManager* manager) {
+    auto scriptEngine = manager->engine();
+
+    scriptEngine->registerGlobalObject("Midi", DependencyManager::get<Midi>().data());
+});
+
 void CALLBACK MidiOutProc(HMIDIOUT hmo, UINT wMsg, DWORD_PTR dwInstance, DWORD_PTR dwParam1, DWORD_PTR dwParam2) {
     switch (wMsg) {
         case MOM_OPEN:
diff --git a/libraries/model-networking/src/model-networking/SimpleMeshProxy.h b/libraries/model-networking/src/model-networking/SimpleMeshProxy.h
index 073eb1c00fc..58c55a5e1f9 100644
--- a/libraries/model-networking/src/model-networking/SimpleMeshProxy.h
+++ b/libraries/model-networking/src/model-networking/SimpleMeshProxy.h
@@ -12,10 +12,6 @@
 #ifndef hifi_SimpleMeshProxy_h
 #define hifi_SimpleMeshProxy_h
 
-#include <QScriptEngine>
-#include <QScriptValueIterator>
-#include <QtScript/QScriptValue>
-
 #include <RegisteredMetaTypes.h>
 
 class SimpleMeshProxy : public MeshProxy {
diff --git a/libraries/networking/src/AssetClient.cpp b/libraries/networking/src/AssetClient.cpp
index 9c0bb846f76..dfa2bf8f359 100644
--- a/libraries/networking/src/AssetClient.cpp
+++ b/libraries/networking/src/AssetClient.cpp
@@ -16,7 +16,6 @@
 #include <QtCore/QBuffer>
 #include <QtCore/QStandardPaths>
 #include <QtCore/QThread>
-#include <QtScript/QScriptEngine>
 #include <QtNetwork/QNetworkDiskCache>
 
 #include <shared/GlobalAppProperties.h>
diff --git a/libraries/networking/src/BaseAssetScriptingInterface.h b/libraries/networking/src/BaseAssetScriptingInterface.h
index 1dcc5ea2ef1..2a4cf779584 100644
--- a/libraries/networking/src/BaseAssetScriptingInterface.h
+++ b/libraries/networking/src/BaseAssetScriptingInterface.h
@@ -9,7 +9,7 @@
 //
 
 // BaseAssetScriptingInterface contains the engine-agnostic support code that can be used from
-// both QML JS and QScriptEngine JS engine implementations
+// both QML JS and ScriptEngine JS engine implementations
 
 #ifndef hifi_BaseAssetScriptingInterface_h
 #define hifi_BaseAssetScriptingInterface_h
diff --git a/libraries/networking/src/ResourceCache.h b/libraries/networking/src/ResourceCache.h
index b78665a7a69..45fd7c1db82 100644
--- a/libraries/networking/src/ResourceCache.h
+++ b/libraries/networking/src/ResourceCache.h
@@ -28,8 +28,6 @@
 #include <QtNetwork/QNetworkReply>
 #include <QtNetwork/QNetworkRequest>
 
-#include <QScriptEngine>
-
 #include <DependencyManager.h>
 
 #include "ResourceManager.h"
@@ -234,7 +232,7 @@ protected slots:
 
     void updateTotalSize(const qint64& deltaSize);
 
-    // Prefetches a resource to be held by the QScriptEngine.
+    // Prefetches a resource to be held by the ScriptEngine.
     // Left as a protected member so subclasses can overload prefetch
     // and delegate to it (see TextureCache::prefetch(const QUrl&, int).
     ScriptableResource* prefetch(const QUrl& url, void* extra, size_t extraHash);
@@ -252,10 +250,10 @@ private slots:
     void clearATPAssets();
 
 protected:
-    // Prefetches a resource to be held by the QScriptEngine.
+    // Prefetches a resource to be held by the ScriptEngine.
     // Pointers created through this method should be owned by the caller,
-    // which should be a QScriptEngine with ScriptableResource registered, so that
-    // the QScriptEngine will delete the pointer when it is garbage collected.
+    // which should be a ScriptEngine with ScriptableResource registered, so that
+    // the ScriptEngine will delete the pointer when it is garbage collected.
     // JSDoc is provided on more general function signature.
     Q_INVOKABLE ScriptableResource* prefetch(const QUrl& url) { return prefetch(url, nullptr, std::numeric_limits<size_t>::max()); }
 
diff --git a/libraries/physics/CMakeLists.txt b/libraries/physics/CMakeLists.txt
index ad4900e4ba1..2d6bbe27b3d 100644
--- a/libraries/physics/CMakeLists.txt
+++ b/libraries/physics/CMakeLists.txt
@@ -14,5 +14,6 @@ include_hifi_library_headers(gpu)
 include_hifi_library_headers(hfm)
 include_hifi_library_headers(model-serializers)
 include_hifi_library_headers(graphics)
+include_hifi_library_headers(script-engine)
 
 target_bullet()
diff --git a/libraries/physics/src/ObjectDynamic.h b/libraries/physics/src/ObjectDynamic.h
index 49fa615b889..96c2f225bbd 100644
--- a/libraries/physics/src/ObjectDynamic.h
+++ b/libraries/physics/src/ObjectDynamic.h
@@ -23,7 +23,7 @@
 
 #include "ObjectMotionState.h"
 #include "BulletUtil.h"
-#include "EntityDynamicInterface.h"
+#include <EntityDynamicInterface.h>
 
 
 class ObjectDynamic : public EntityDynamicInterface, public ReadWriteLockable {
diff --git a/libraries/pointers/CMakeLists.txt b/libraries/pointers/CMakeLists.txt
index e33c76e2495..184e9ae5549 100644
--- a/libraries/pointers/CMakeLists.txt
+++ b/libraries/pointers/CMakeLists.txt
@@ -2,4 +2,4 @@ set(TARGET_NAME pointers)
 setup_hifi_library()
 GroupSources(src)
 link_hifi_libraries(shared controllers)
-
+include_hifi_library_headers(script-engine)
diff --git a/libraries/recording/CMakeLists.txt b/libraries/recording/CMakeLists.txt
index b42a4018f8c..ef357fdd5d7 100644
--- a/libraries/recording/CMakeLists.txt
+++ b/libraries/recording/CMakeLists.txt
@@ -1,9 +1,9 @@
 set(TARGET_NAME recording)
 
 # set a default root dir for each of our optional externals if it was not passed
-setup_hifi_library(Script)
+setup_hifi_library()
 
 # use setup_hifi_library macro to setup our project and link appropriate Qt modules
-link_hifi_libraries(shared networking)
+link_hifi_libraries(shared networking script-engine)
 
 GroupSources("src/recording")
diff --git a/libraries/script-engine/src/RecordingScriptingInterface.cpp b/libraries/recording/src/recording/RecordingScriptingInterface.cpp
similarity index 83%
rename from libraries/script-engine/src/RecordingScriptingInterface.cpp
rename to libraries/recording/src/recording/RecordingScriptingInterface.cpp
index cbcf94662e2..82fefe26952 100644
--- a/libraries/script-engine/src/RecordingScriptingInterface.cpp
+++ b/libraries/recording/src/recording/RecordingScriptingInterface.cpp
@@ -11,7 +11,6 @@
 #include <QStandardPaths>
 #include <QtCore/QThread>
 #include <QtCore/QUrl>
-#include <QtScript/QScriptValue>
 #include <QtWidgets/QFileDialog>
 
 #include <shared/QtHelpers.h>
@@ -21,13 +20,16 @@
 #include <NumericalConstants.h>
 #include <PathUtils.h>
 #include <Transform.h>
-#include <recording/Deck.h>
-#include <recording/Recorder.h>
-#include <recording/Clip.h>
-#include <recording/Frame.h>
-#include <recording/ClipCache.h>
+#include "Deck.h"
+#include "Recorder.h"
+#include "Clip.h"
+#include "Frame.h"
+#include "ClipCache.h"
 
-#include "ScriptEngineLogging.h"
+#include <ScriptEngine.h>
+#include <ScriptEngineLogging.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
 using namespace recording;
 
@@ -54,18 +56,19 @@ float RecordingScriptingInterface::playerLength() const {
     return _player->length();
 }
 
-void RecordingScriptingInterface::playClip(NetworkClipLoaderPointer clipLoader, const QString& url, QScriptValue callback) {
+void RecordingScriptingInterface::playClip(NetworkClipLoaderPointer clipLoader, const QString& url, const ScriptValue& callback) {
     _player->queueClip(clipLoader->getClip());
 
     if (callback.isFunction()) {
-        QScriptValueList args { true, url };
-        callback.call(QScriptValue(), args);
+        auto engine = callback.engine();
+        ScriptValueList args{ engine->newValue(true), engine->newValue(url) };
+        callback.call(ScriptValue(), args);
     }
 }
 
-void RecordingScriptingInterface::loadRecording(const QString& url, QScriptValue callback) {
+void RecordingScriptingInterface::loadRecording(const QString& url, const ScriptValue& callback) {
     if (QThread::currentThread() != thread()) {
-        BLOCKING_INVOKE_METHOD(this, "loadRecording", Q_ARG(const QString&, url), Q_ARG(QScriptValue, callback));
+        BLOCKING_INVOKE_METHOD(this, "loadRecording", Q_ARG(const QString&, url), Q_ARG(const ScriptValue&, callback));
         return;
     }
 
@@ -82,8 +85,14 @@ void RecordingScriptingInterface::loadRecording(const QString& url, QScriptValue
 
     auto weakClipLoader = clipLoader.toWeakRef();
 
+    auto manager = callback.engine()->manager();
+    if (!manager) {
+        qWarning() << "This script does not belong to a ScriptManager";
+        return;
+    }
+
     // when clip loaded, call the callback with the URL and success boolean
-    connect(clipLoader.data(), &recording::NetworkClipLoader::clipLoaded, callback.engine(),
+    connect(clipLoader.data(), &recording::NetworkClipLoader::clipLoaded, manager,
             [this, weakClipLoader, url, callback]() mutable {
 
         if (auto clipLoader = weakClipLoader.toStrongRef()) {
@@ -97,12 +106,14 @@ void RecordingScriptingInterface::loadRecording(const QString& url, QScriptValue
     });
 
     // when clip load fails, call the callback with the URL and failure boolean
-    connect(clipLoader.data(), &recording::NetworkClipLoader::failed, callback.engine(), [this, weakClipLoader, url, callback](QNetworkReply::NetworkError error) mutable {
+    connect(clipLoader.data(), &recording::NetworkClipLoader::failed, manager,
+            [this, weakClipLoader, url, callback](QNetworkReply::NetworkError error) mutable {
         qCDebug(scriptengine) << "Failed to load recording from\"" << url << '"';
 
         if (callback.isFunction()) {
-            QScriptValueList args { false, url };
-            callback.call(QScriptValue(), args);
+            auto engine = callback.engine();
+            ScriptValueList args{ engine->newValue(false), engine->newValue(url) };
+            callback.call(ScriptValue(), args);
         }
 
         if (auto clipLoader = weakClipLoader.toStrongRef()) {
@@ -248,7 +259,7 @@ void RecordingScriptingInterface::saveRecording(const QString& filename) {
     recording::Clip::toFile(filename, _lastClip);
 }
 
-bool RecordingScriptingInterface::saveRecordingToAsset(QScriptValue getClipAtpUrl) {
+bool RecordingScriptingInterface::saveRecordingToAsset(const ScriptValue& getClipAtpUrl) {
     if (!getClipAtpUrl.isFunction()) {
         qCWarning(scriptengine) << "The argument is not a function.";
         return false;
@@ -258,7 +269,7 @@ bool RecordingScriptingInterface::saveRecordingToAsset(QScriptValue getClipAtpUr
         bool result;
         BLOCKING_INVOKE_METHOD(this, "saveRecordingToAsset",
             Q_RETURN_ARG(bool, result),
-            Q_ARG(QScriptValue, getClipAtpUrl));
+            Q_ARG(const ScriptValue&, getClipAtpUrl));
         return result;
     }
 
@@ -267,9 +278,14 @@ bool RecordingScriptingInterface::saveRecordingToAsset(QScriptValue getClipAtpUr
         return false;
     }
 
+    auto manager = getClipAtpUrl.engine()->manager();
+    if (!manager) {
+        qWarning() << "This script does not belong to a ScriptManager";
+        return false;
+    }
+
     if (auto upload = DependencyManager::get<AssetClient>()->createUpload(recording::Clip::toBuffer(_lastClip))) {
-        QObject::connect(upload, &AssetUpload::finished,
-                         getClipAtpUrl.engine(), [=](AssetUpload* upload, const QString& hash) mutable {
+        QObject::connect(upload, &AssetUpload::finished, manager, [=](AssetUpload* upload, const QString& hash) mutable {
             QString clip_atp_url = "";
 
             if (upload->getError() == AssetUpload::NoError) {
@@ -280,9 +296,9 @@ bool RecordingScriptingInterface::saveRecordingToAsset(QScriptValue getClipAtpUr
                 qCWarning(scriptengine) << "Error during the Asset upload.";
             }
 
-            QScriptValueList args;
-            args << clip_atp_url;
-            getClipAtpUrl.call(QScriptValue(), args);
+            ScriptValueList args;
+            args << getClipAtpUrl.engine()->newValue(clip_atp_url);
+            getClipAtpUrl.call(ScriptValue(), args);
         });
         upload->start();
         return true;
diff --git a/libraries/script-engine/src/RecordingScriptingInterface.h b/libraries/recording/src/recording/RecordingScriptingInterface.h
similarity index 97%
rename from libraries/script-engine/src/RecordingScriptingInterface.h
rename to libraries/recording/src/recording/RecordingScriptingInterface.h
index a170958a918..126c81e3b43 100644
--- a/libraries/script-engine/src/RecordingScriptingInterface.h
+++ b/libraries/recording/src/recording/RecordingScriptingInterface.h
@@ -18,14 +18,12 @@
 #include <QtCore/QObject>
 #include <QtCore/QSharedPointer>
 
-#include <BaseScriptEngine.h>
 #include <DependencyManager.h>
-#include <recording/ClipCache.h>
-#include <recording/Forward.h>
-#include <recording/Frame.h>
+#include <ScriptValue.h>
 
-class QScriptEngine;
-class QScriptValue;
+#include "ClipCache.h"
+#include "Forward.h"
+#include "Frame.h"
 
 /*@jsdoc
  * The <code>Recording</code> API makes and plays back recordings of voice and avatar movements. Playback may be done on a 
@@ -73,7 +71,7 @@ public slots:
      *     });
      * }
      */
-    void loadRecording(const QString& url, QScriptValue callback = QScriptValue());
+    void loadRecording(const QString& url, const ScriptValue& callback = ScriptValue());
 
 
     /*@jsdoc
@@ -337,7 +335,7 @@ public slots:
      *     }
      * }, 5000);
      */
-    bool saveRecordingToAsset(QScriptValue getClipAtpUrl);
+    bool saveRecordingToAsset(const ScriptValue& getClipAtpUrl);
 
     /*@jsdoc
      * Loads the most recently made recording and plays it back on your avatar.
@@ -370,7 +368,7 @@ public slots:
     QSet<recording::NetworkClipLoaderPointer> _clipLoaders;
 
 private:
-    void playClip(recording::NetworkClipLoaderPointer clipLoader, const QString& url, QScriptValue callback);
+    void playClip(recording::NetworkClipLoaderPointer clipLoader, const QString& url, const ScriptValue& callback);
 };
 
 #endif // hifi_RecordingScriptingInterface_h
diff --git a/libraries/render-utils/CMakeLists.txt b/libraries/render-utils/CMakeLists.txt
index 904e7ea94c6..6ac1a3518e1 100644
--- a/libraries/render-utils/CMakeLists.txt
+++ b/libraries/render-utils/CMakeLists.txt
@@ -2,11 +2,12 @@ set(TARGET_NAME render-utils)
 
 # pull in the resources.qrc file
 qt5_add_resources(QT_RESOURCES_FILE "${CMAKE_CURRENT_SOURCE_DIR}/res/fonts/fonts.qrc")
-setup_hifi_library(Gui Network Qml Quick Script)
+setup_hifi_library(Gui Network Qml Quick)
 link_hifi_libraries(shared task ktx gpu shaders graphics graphics-scripting material-networking model-networking render animation model-serializers image procedural)
 include_hifi_library_headers(audio)
 include_hifi_library_headers(networking)
 include_hifi_library_headers(octree)
+include_hifi_library_headers(script-engine)
 include_hifi_library_headers(hfm)
 
 # tell CMake to exclude qrc_fonts.cpp for policy CMP0071
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index af477a2f09c..15658b053df 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -45,7 +45,6 @@
 #define SKIN_DQ
 
 class AbstractViewStateInterface;
-class QScriptEngine;
 
 class ViewFrustum;
 
diff --git a/libraries/script-engine/CMakeLists.txt b/libraries/script-engine/CMakeLists.txt
index 6def6c185fa..ec30d52bfc7 100644
--- a/libraries/script-engine/CMakeLists.txt
+++ b/libraries/script-engine/CMakeLists.txt
@@ -1,18 +1,12 @@
 set(TARGET_NAME script-engine)
 # FIXME Move undo scripting interface to application and remove Widgets
-setup_hifi_library(Gui Network Script ScriptTools WebSockets Widgets)
+setup_hifi_library(Network Script WebSockets)
 
 target_zlib()
 if (NOT ANDROID)
   target_quazip()
 endif ()
 
-link_hifi_libraries(shared networking shaders material-networking model-networking recording avatars model-serializers entities controllers animation audio midi)
-include_hifi_library_headers(gl)
-include_hifi_library_headers(hfm)
-include_hifi_library_headers(gpu)
-include_hifi_library_headers(ktx)
-include_hifi_library_headers(image)
-include_hifi_library_headers(graphics)
+link_hifi_libraries(networking)
 include_hifi_library_headers(octree)
-include_hifi_library_headers(procedural)
\ No newline at end of file
+include_hifi_library_headers(shared)
diff --git a/libraries/script-engine/src/AbstractScriptingServicesInterface.h b/libraries/script-engine/src/AbstractScriptingServicesInterface.h
index c3acac7c766..5c99240e906 100644
--- a/libraries/script-engine/src/AbstractScriptingServicesInterface.h
+++ b/libraries/script-engine/src/AbstractScriptingServicesInterface.h
@@ -15,13 +15,16 @@
 #ifndef hifi_AbstractScriptingServicesInterface_h
 #define hifi_AbstractScriptingServicesInterface_h
 
-#include <BaseScriptEngine.h>
+#include <memory>
+
+class ScriptManager;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
 
 /// Interface provided by Application to other objects that need access to scripting services of the application
 class AbstractScriptingServicesInterface {
 public:
     /// Registers application specific services with a script engine.
-    virtual void registerScriptEngineWithApplicationServices(const ScriptEnginePointer& scriptEngine) = 0;
+    virtual void registerScriptEngineWithApplicationServices(const ScriptManagerPointer& scriptEngine) = 0;
 };
 
 
diff --git a/libraries/script-engine/src/AssetScriptingInterface.cpp b/libraries/script-engine/src/AssetScriptingInterface.cpp
index 8f97f1ce336..99ef12ab62c 100644
--- a/libraries/script-engine/src/AssetScriptingInterface.cpp
+++ b/libraries/script-engine/src/AssetScriptingInterface.cpp
@@ -13,18 +13,20 @@
 
 #include <QMimeDatabase>
 #include <QThread>
-#include <QtScript/QScriptEngine>
 
 #include <AssetRequest.h>
 #include <AssetUpload.h>
 #include <AssetUtils.h>
-#include <BaseScriptEngine.h>
 #include <MappingRequest.h>
 #include <NodeList.h>
 
 #include <RegisteredMetaTypes.h>
 #include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
 #include "ScriptEngineLogging.h"
+#include "ScriptManager.h"
+#include "ScriptValue.h"
+#include "ScriptValueUtils.h"
 
 #include <shared/QtHelpers.h>
 #include <Gzip.h>
@@ -35,7 +37,9 @@ using Promise = MiniPromise::Promise;
 
 AssetScriptingInterface::AssetScriptingInterface(QObject* parent) : BaseAssetScriptingInterface(parent) {
     qCDebug(scriptengine) << "AssetScriptingInterface::AssetScriptingInterface" << parent;
-    MiniPromise::registerMetaTypes(parent);
+
+    auto scriptManager = qobject_cast<ScriptManager*>(parent);
+    scriptRegisterMetaType(scriptManager->engine().get(), promiseToScriptValue, promiseFromScriptValue);
 }
 
 #define JS_VERIFY(cond, error) { if (!this->jsVerify(cond, error)) { return; } }
@@ -59,16 +63,17 @@ bool AssetScriptingInterface::initializeCache() {
     }
 }
 
-void AssetScriptingInterface::uploadData(QString data, QScriptValue callback) {
+void AssetScriptingInterface::uploadData(QString data, const ScriptValue& callback) {
     auto handler = jsBindCallback(thisObject(), callback);
     QByteArray dataByteArray = data.toUtf8();
     auto upload = DependencyManager::get<AssetClient>()->createUpload(dataByteArray);
 
     Promise deferred = makePromise(__FUNCTION__);
+    auto scriptEngine = engine();
     deferred->ready([=](QString error, QVariantMap result) {
         auto url = result.value("url").toString();
         auto hash = result.value("hash").toString();
-        jsCallback(handler, url, hash);
+        jsCallback(handler, scriptEngine->newValue(url), scriptEngine->newValue(hash));
     });
 
     connect(upload, &AssetUpload::finished, upload, [deferred](AssetUpload* upload, const QString& hash) {
@@ -83,12 +88,13 @@ void AssetScriptingInterface::uploadData(QString data, QScriptValue callback) {
     upload->start();
 }
 
-void AssetScriptingInterface::setMapping(QString path, QString hash, QScriptValue callback) {
+void AssetScriptingInterface::setMapping(QString path, QString hash, const ScriptValue& callback) {
     auto handler = jsBindCallback(thisObject(), callback);
     auto setMappingRequest = assetClient()->createSetMappingRequest(path, hash);
     Promise deferred = makePromise(__FUNCTION__);
+    auto scriptEngine = engine();
     deferred->ready([=](QString error, QVariantMap result) {
-        jsCallback(handler, error, result);
+        jsCallback(handler, scriptEngine->newValue(error), result);
     });
 
     connect(setMappingRequest, &SetMappingRequest::finished, setMappingRequest, [deferred](SetMappingRequest* request) {
@@ -107,7 +113,7 @@ void AssetScriptingInterface::setMapping(QString path, QString hash, QScriptValu
  * @typedef {object} Assets.DownloadDataError
  * @property {string} errorMessage - <code>""</code> if the download was successful, otherwise a description of the error.
  */
-void AssetScriptingInterface::downloadData(QString urlString, QScriptValue callback) {
+void AssetScriptingInterface::downloadData(QString urlString, const ScriptValue& callback) {
     // FIXME: historically this API method failed silently when given a non-atp prefixed
     //   urlString (or if the AssetRequest failed).
     // .. is that by design or could we update without breaking things to provide better feedback to scripts?
@@ -123,9 +129,10 @@ void AssetScriptingInterface::downloadData(QString urlString, QScriptValue callb
     auto assetRequest = assetClient->createRequest(hash);
 
     Promise deferred = makePromise(__FUNCTION__);
+    auto scriptEngine = engine();
     deferred->ready([=](QString error, QVariantMap result) {
         // FIXME: to remain backwards-compatible the signature here is "callback(data, n/a)"
-        jsCallback(handler, result.value("data").toString(), { { "errorMessage", error } });
+        jsCallback(handler, scriptEngine->newValue(result.value("data").toString()), { { "errorMessage", error } });
     });
 
     connect(assetRequest, &AssetRequest::finished, assetRequest, [deferred](AssetRequest* request) {
@@ -149,7 +156,7 @@ void AssetScriptingInterface::downloadData(QString urlString, QScriptValue callb
     assetRequest->start();
 }
 
-void AssetScriptingInterface::setBakingEnabled(QString path, bool enabled, QScriptValue callback) {
+void AssetScriptingInterface::setBakingEnabled(QString path, bool enabled, const ScriptValue& callback) {
     auto setBakingEnabledRequest = DependencyManager::get<AssetClient>()->createSetBakingEnabledRequest({ path }, enabled);
 
     Promise deferred = jsPromiseReady(makePromise(__FUNCTION__), thisObject(), callback);
@@ -179,14 +186,15 @@ void AssetScriptingInterface::sendFakedHandshake() {
 
 #endif
 
-void AssetScriptingInterface::getMapping(QString asset, QScriptValue callback) {
+void AssetScriptingInterface::getMapping(QString asset, const ScriptValue& callback) {
     auto path = AssetUtils::getATPUrl(asset).path();
     auto handler = jsBindCallback(thisObject(), callback);
     JS_VERIFY(AssetUtils::isValidFilePath(path), "invalid ATP file path: " + asset + "(path:"+path+")");
     JS_VERIFY(callback.isFunction(), "expected second parameter to be a callback function");
     Promise promise = getAssetInfo(path);
+    auto scriptEngine = engine();
     promise->ready([=](QString error, QVariantMap result) {
-        jsCallback(handler, error, result.value("hash").toString());
+        jsCallback(handler, scriptEngine->newValue(error), scriptEngine->newValue(result.value("hash").toString()));
     });
 }
 
@@ -202,45 +210,46 @@ bool AssetScriptingInterface::jsVerify(bool condition, const QString& error) {
     return false;
 }
 
-QScriptValue AssetScriptingInterface::jsBindCallback(QScriptValue scope, QScriptValue callback) {
-    QScriptValue handler = ::makeScopedHandlerObject(scope, callback);
-    QScriptValue value = handler.property("callback");
+ScriptValue AssetScriptingInterface::jsBindCallback(const ScriptValue& scope, const ScriptValue& callback) {
+    ScriptValue handler = ::makeScopedHandlerObject(scope, callback);
+    ScriptValue value = handler.property("callback");
     if (!jsVerify(handler.isObject() && value.isFunction(),
                  QString("jsBindCallback -- .callback is not a function (%1)").arg(value.toVariant().typeName()))) {
-        return QScriptValue();
+        return ScriptValue();
     }
     return handler;
 }
 
-Promise AssetScriptingInterface::jsPromiseReady(Promise promise, QScriptValue scope, QScriptValue callback) {
+Promise AssetScriptingInterface::jsPromiseReady(Promise promise, const ScriptValue& scope, const ScriptValue& callback) {
     auto handler = jsBindCallback(scope, callback);
     if (!jsVerify(handler.isValid(), "jsPromiseReady -- invalid callback handler")) {
         return nullptr;
     }
-    return promise->ready([this, handler](QString error, QVariantMap result) {
-        jsCallback(handler, error, result);
+    auto scriptEngine = engine();
+    return promise->ready([this, handler, scriptEngine](QString error, QVariantMap result) {
+        jsCallback(handler, scriptEngine->newValue(error), result);
     });
 }
 
-void AssetScriptingInterface::jsCallback(const QScriptValue& handler,
-                                         const QScriptValue& error, const QScriptValue& result) {
+void AssetScriptingInterface::jsCallback(const ScriptValue& handler,
+                                         const ScriptValue& error, const ScriptValue& result) {
     Q_ASSERT(thread() == QThread::currentThread());
-    auto errorValue = !error.toBool() ? QScriptValue::NullValue : error;
+    auto errorValue = !error.toBool() ? engine()->nullValue() : error;
     JS_VERIFY(handler.isObject() && handler.property("callback").isFunction(),
               QString("jsCallback -- .callback is not a function (%1)")
               .arg(handler.property("callback").toVariant().typeName()));
     ::callScopedHandlerObject(handler, errorValue, result);
 }
 
-void AssetScriptingInterface::jsCallback(const QScriptValue& handler,
-                                         const QScriptValue& error, const QVariantMap& result) {
+void AssetScriptingInterface::jsCallback(const ScriptValue& handler,
+                                         const ScriptValue& error, const QVariantMap& result) {
     Q_ASSERT(thread() == QThread::currentThread());
     Q_ASSERT(handler.engine());
     auto engine = handler.engine();
     jsCallback(handler, error, engine->toScriptValue(result));
 }
 
-void AssetScriptingInterface::deleteAsset(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::deleteAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     jsVerify(false, "TODO: deleteAsset API");
 }
 
@@ -270,7 +279,7 @@ void AssetScriptingInterface::deleteAsset(QScriptValue options, QScriptValue sco
  * @property {boolean} [wasRedirected] - <code>true</code> if the downloaded data is the baked version of the asset, 
  *      <code>false</code> if it isn't baked.
  */
-void AssetScriptingInterface::getAsset(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::getAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     JS_VERIFY(options.isObject() || options.isString(), "expected request options Object or URL as first parameter");
 
     auto decompress = options.property("decompress").toBool() || options.property("compressed").toBool();
@@ -336,7 +345,7 @@ void AssetScriptingInterface::getAsset(QScriptValue options, QScriptValue scope,
  * @property {boolean} [wasRedirected] - <code>true</code> if the resolved data is for the baked version of the asset,
  *      <code>false</code> if it isn't.
  */
-void AssetScriptingInterface::resolveAsset(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::resolveAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     const QString& URL{ "url" };
 
     auto url = (options.isString() ? options : options.property(URL)).toString();
@@ -363,9 +372,9 @@ void AssetScriptingInterface::resolveAsset(QScriptValue options, QScriptValue sc
  * @property {string|object|ArrayBuffer} [response] - The decompressed data.
  * @property {Assets.ResponseType} [responseType] - The type of the decompressed data in <code>response</code>.
  */
-void AssetScriptingInterface::decompressData(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::decompressData(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     auto data = options.property("data");
-    QByteArray dataByteArray = qscriptvalue_cast<QByteArray>(data);
+    QByteArray dataByteArray = scriptvalue_cast<QByteArray>(data);
     auto responseType = options.property("responseType").toString().toLower();
     if (responseType.isEmpty()) {
         responseType = "text";
@@ -404,9 +413,9 @@ namespace {
  * @property {string} [contentType] - The MIME type of the compressed data, i.e., <code>"application/gzip"</code>.
  * @property {ArrayBuffer} [data] - The compressed data.
  */
-void AssetScriptingInterface::compressData(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::compressData(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     auto data = options.property("data").isValid() ? options.property("data") : options;
-    QByteArray dataByteArray = data.isString() ? data.toString().toUtf8() : qscriptvalue_cast<QByteArray>(data);
+    QByteArray dataByteArray = data.isString() ? data.toString().toUtf8() : scriptvalue_cast<QByteArray>(data);
     int level = options.property("level").isNumber() ? options.property("level").toInt32() : DEFAULT_GZIP_COMPRESSION_LEVEL;
     JS_VERIFY(level >= DEFAULT_GZIP_COMPRESSION_LEVEL || level <= MAX_GZIP_COMPRESSION_LEVEL, QString("invalid .level %1").arg(level));
     jsPromiseReady(compressBytes(dataByteArray, level), scope, callback);
@@ -433,13 +442,13 @@ void AssetScriptingInterface::compressData(QScriptValue options, QScriptValue sc
  * @property {string} [url] - The <code>atp:</code> URL of the content: using the path if specified, otherwise the hash.
  * @property {string} [path] - The uploaded content's mapped path, if specified.
  */
-void AssetScriptingInterface::putAsset(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::putAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     auto compress = options.property("compress").toBool() || options.property("compressed").toBool();
     auto data = options.isObject() ? options.property("data") : options;
     auto rawPath = options.property("path").toString();
     auto path = AssetUtils::getATPUrl(rawPath).path();
 
-    QByteArray dataByteArray = data.isString() ? data.toString().toUtf8() : qscriptvalue_cast<QByteArray>(data);
+    QByteArray dataByteArray = data.isString() ? data.toString().toUtf8() : scriptvalue_cast<QByteArray>(data);
 
     JS_VERIFY(path.isEmpty() || AssetUtils::isValidFilePath(path),
               QString("expected valid ATP file path '%1' ('%2')").arg(rawPath).arg(path));
@@ -489,7 +498,7 @@ void AssetScriptingInterface::putAsset(QScriptValue options, QScriptValue scope,
  * @property {string} url - The URL of the cached asset to get information on. Must start with <code>"atp:"</code> or 
  *     <code>"cache:"</code>.
  */
-void AssetScriptingInterface::queryCacheMeta(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::queryCacheMeta(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     QString url = options.isString() ? options.toString() : options.property("url").toString();
     JS_VERIFY(QUrl(url).isValid(), QString("Invalid URL '%1'").arg(url));
     jsPromiseReady(Parent::queryCacheMeta(url), scope, callback);
@@ -504,7 +513,7 @@ void AssetScriptingInterface::queryCacheMeta(QScriptValue options, QScriptValue
  * @property {string} url - The URL of the asset to load from cache. Must start with <code>"atp:"</code> or
  *     <code>"cache:"</code>.
  */
-void AssetScriptingInterface::loadFromCache(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::loadFromCache(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     QString url, responseType;
     bool decompress = false;
     if (options.isString()) {
@@ -523,14 +532,14 @@ void AssetScriptingInterface::loadFromCache(QScriptValue options, QScriptValue s
 }
 
 bool AssetScriptingInterface::canWriteCacheValue(const QUrl& url) {
-    auto scriptEngine = qobject_cast<ScriptEngine*>(engine());
-    if (!scriptEngine) {
+    auto scriptManager = engine()->manager();
+    if (!scriptManager) {
         return false;
     }
     // allow cache writes only from Client, EntityServer and Agent scripts
     bool isAllowedContext = (
-        scriptEngine->isClientScript() ||
-        scriptEngine->isAgentScript()
+        scriptManager->isClientScript() ||
+        scriptManager->isAgentScript()
     );
     if (!isAllowedContext) {
         return false;
@@ -546,17 +555,21 @@ bool AssetScriptingInterface::canWriteCacheValue(const QUrl& url) {
  * @property {string} [url] - The URL to associate with the cache item. Must start with <code>"atp:"</code> or
  *     <code>"cache:"</code>. If not specified, the URL is <code>"atp:"</code> followed by the SHA256 hash of the content.
  */
-void AssetScriptingInterface::saveToCache(QScriptValue options, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::saveToCache(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback) {
     JS_VERIFY(options.isObject(), QString("expected options object as first parameter not: %1").arg(options.toVariant().typeName()));
 
     QString url = options.property("url").toString();
-    QByteArray data = qscriptvalue_cast<QByteArray>(options.property("data"));
-    QVariantMap headers = qscriptvalue_cast<QVariantMap>(options.property("headers"));
+    QByteArray data = scriptvalue_cast<QByteArray>(options.property("data"));
+    QVariantMap headers = scriptvalue_cast<QVariantMap>(options.property("headers"));
 
     saveToCache(url, data, headers, scope, callback);
 }
 
-void AssetScriptingInterface::saveToCache(const QUrl& rawURL, const QByteArray& data, const QVariantMap& metadata, QScriptValue scope, QScriptValue callback) {
+void AssetScriptingInterface::saveToCache(const QUrl& rawURL,
+                                          const QByteArray& data,
+                                          const QVariantMap& metadata,
+                                          const ScriptValue& scope,
+                                          const ScriptValue& callback) {
     QUrl url = rawURL;
     if (url.path().isEmpty() && !data.isEmpty()) {
         // generate a valid ATP URL from the data  -- appending any existing fragment or querystring values
diff --git a/libraries/script-engine/src/AssetScriptingInterface.h b/libraries/script-engine/src/AssetScriptingInterface.h
index b9fcb3c1c7b..afec316e9a2 100644
--- a/libraries/script-engine/src/AssetScriptingInterface.h
+++ b/libraries/script-engine/src/AssetScriptingInterface.h
@@ -19,14 +19,14 @@
 
 #include <QtCore/QObject>
 #include <QtCore/QThread>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptable>
 #include <AssetClient.h>
 #include <NetworkAccessManager.h>
 #include <BaseAssetScriptingInterface.h>
-#include <BaseScriptEngine.h>
 #include <QtNetwork/QNetworkDiskCache>
 
+#include "Scriptable.h"
+#include "ScriptValue.h"
+
 /*@jsdoc
  * The <code>Assets</code> API provides facilities for interacting with the domain's asset server and the client cache. 
  * <p>Assets are stored in the asset server in files with SHA256 names. These files are mapped to user-friendly URLs of the 
@@ -45,7 +45,7 @@
  * @hifi-assignment-client
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Assets.html">Assets</a></code> scripting API
-class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable {
+class AssetScriptingInterface : public BaseAssetScriptingInterface, Scriptable {
     Q_OBJECT
 public:
     using Parent = BaseAssetScriptingInterface;
@@ -76,7 +76,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     });
      * });
      */
-    Q_INVOKABLE void uploadData(QString data, QScriptValue callback);
+    Q_INVOKABLE void uploadData(QString data, const ScriptValue& callback);
 
     /*@jsdoc
      * Called when an {@link Assets.downloadData} call is complete.
@@ -112,7 +112,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     });
      * }, 1000);
      */
-    Q_INVOKABLE void downloadData(QString url, QScriptValue callback);
+    Q_INVOKABLE void downloadData(QString url, const ScriptValue& callback);
 
     /*@jsdoc
      * Called when an {@link Assets.setMapping} call is complete.
@@ -126,7 +126,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      * @param {string} hash - The hash in the asset server.
      * @param {Assets~setMappingCallback} callback - The function to call upon completion.
      */
-    Q_INVOKABLE void setMapping(QString path, QString hash, QScriptValue callback);
+    Q_INVOKABLE void setMapping(QString path, QString hash, const ScriptValue& callback);
 
     /*@jsdoc
      * Called when an {@link Assets.getMapping} call is complete.
@@ -150,7 +150,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     });
      * }
      */
-    Q_INVOKABLE void getMapping(QString path, QScriptValue callback);
+    Q_INVOKABLE void getMapping(QString path, const ScriptValue& callback);
 
     /*@jsdoc
      * Called when an {@link Assets.setBakingEnabled} call is complete.
@@ -166,7 +166,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      * @param {Assets~setBakingEnabledCallback} callback - The function to call upon completion.
      */
     // Note: Second callback parameter not documented because it's always {}.
-    Q_INVOKABLE void setBakingEnabled(QString path, bool enabled, QScriptValue callback);
+    Q_INVOKABLE void setBakingEnabled(QString path, bool enabled, const ScriptValue& callback);
 
 #if (PR_BUILD || DEV_BUILD)
     /**
@@ -222,7 +222,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void getAsset(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void getAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
 
     /*@jsdoc
      * Called when an {@link Assets.putAsset} call is complete.
@@ -259,7 +259,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void putAsset(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void putAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
 
     /*@jsdoc
      * Called when an {@link Assets.deleteAsset} call is complete.
@@ -276,7 +276,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      * @param {object} scope - The scope that the <code>callback</code> function is defined in.
      * @param {Assets~deleteAssetCallback} callback - The function to call upon completion.
      */
-    Q_INVOKABLE void deleteAsset(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void deleteAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
 
     /*@jsdoc
      * Called when an {@link Assets.resolveAsset} call is complete.
@@ -310,7 +310,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void resolveAsset(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void resolveAsset(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Called when an {@link Assets.decompressData} call is complete.
@@ -331,7 +331,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     in a string. If the name of a function or a function identifier, it must be a member of the scope specified by
      *     <code>scopeOrCallback</code>.</p>
      */
-    Q_INVOKABLE void decompressData(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void decompressData(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Called when an {@link Assets.compressData} call is complete.
@@ -353,7 +353,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     in a string. If the name of a function or a function identifier, it must be a member of the scope specified by
      *     <code>scopeOrCallback</code>.</p>
      */
-    Q_INVOKABLE void compressData(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void compressData(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Initializes the cache if it isn't already initialized.
@@ -398,7 +398,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     print("- Status: " + JSON.stringify(status));
      * });
      */
-    Q_INVOKABLE void getCacheStatus(QScriptValue scope, QScriptValue callback = QScriptValue()) {
+    Q_INVOKABLE void getCacheStatus(const ScriptValue& scope, const ScriptValue& callback = ScriptValue()) {
         jsPromiseReady(Parent::getCacheStatus(), scope, callback);
     }
 
@@ -438,7 +438,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void queryCacheMeta(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void queryCacheMeta(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Called when an {@link Assets.loadFromCache} call is complete.
@@ -478,7 +478,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void loadFromCache(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void loadFromCache(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Called when an {@link Assets.saveToCache} call is complete.
@@ -517,7 +517,7 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     }
      * );
      */
-    Q_INVOKABLE void saveToCache(QScriptValue options, QScriptValue scope, QScriptValue callback = QScriptValue());
+    Q_INVOKABLE void saveToCache(const ScriptValue& options, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
     
     /*@jsdoc
      * Saves asset data to the cache directly, without downloading it from a URL.
@@ -537,13 +537,13 @@ class AssetScriptingInterface : public BaseAssetScriptingInterface, QScriptable
      *     <code>scopeOrCallback</code>.</p>
      */
     Q_INVOKABLE void saveToCache(const QUrl& url, const QByteArray& data, const QVariantMap& metadata,
-                                 QScriptValue scope, QScriptValue callback = QScriptValue());
+                                 const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
 protected:
-    QScriptValue jsBindCallback(QScriptValue scope, QScriptValue callback = QScriptValue());
-    Promise jsPromiseReady(Promise promise, QScriptValue scope, QScriptValue callback = QScriptValue());
+    ScriptValue jsBindCallback(const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
+    Promise jsPromiseReady(Promise promise, const ScriptValue& scope, const ScriptValue& callback = ScriptValue());
 
-    void jsCallback(const QScriptValue& handler, const QScriptValue& error, const QVariantMap& result);
-    void jsCallback(const QScriptValue& handler, const QScriptValue& error, const QScriptValue& result);
+    void jsCallback(const ScriptValue& handler, const ScriptValue& error, const QVariantMap& result);
+    void jsCallback(const ScriptValue& handler, const ScriptValue& error, const ScriptValue& result);
     bool jsVerify(bool condition, const QString& error);
 };
 
diff --git a/libraries/script-engine/src/ConsoleScriptingInterface.cpp b/libraries/script-engine/src/ConsoleScriptingInterface.cpp
index 60de04aa9ea..e8a4de24ad1 100644
--- a/libraries/script-engine/src/ConsoleScriptingInterface.cpp
+++ b/libraries/script-engine/src/ConsoleScriptingInterface.cpp
@@ -19,7 +19,10 @@
 
 #include <QtCore/QDateTime>
 
+#include "ScriptContext.h"
 #include "ScriptEngine.h"
+#include "ScriptManager.h"
+#include "ScriptValue.h"
 
 #define INDENTATION 4 // 1 Tab - 4 spaces
 const QString LINE_SEPARATOR = "\n    ";
@@ -27,71 +30,71 @@ const QString SPACE_SEPARATOR = " ";
 const QString STACK_TRACE_FORMAT = "\n[Stacktrace]%1%2";
 QList<QString> ConsoleScriptingInterface::_groupDetails = QList<QString>();
 
-QScriptValue ConsoleScriptingInterface::info(QScriptContext* context, QScriptEngine* engine) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptInfoMessage(appendArguments(context));
+ScriptValue ConsoleScriptingInterface::info(ScriptContext* context, ScriptEngine* engine) {
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptInfoMessage(appendArguments(context));
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::log(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue ConsoleScriptingInterface::log(ScriptContext* context, ScriptEngine* engine) {
     QString message = appendArguments(context);
     if (_groupDetails.count() == 0) {
-        if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-            scriptEngine->scriptPrintedMessage(message);
+        if (ScriptManager* scriptManager = engine->manager()) {
+            scriptManager->scriptPrintedMessage(message);
         }
     } else {
         logGroupMessage(message, engine);
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::debug(QScriptContext* context, QScriptEngine* engine) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptPrintedMessage(appendArguments(context));
+ScriptValue ConsoleScriptingInterface::debug(ScriptContext* context, ScriptEngine* engine) {
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptPrintedMessage(appendArguments(context));
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::warn(QScriptContext* context, QScriptEngine* engine) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptWarningMessage(appendArguments(context));
+ScriptValue ConsoleScriptingInterface::warn(ScriptContext* context, ScriptEngine* engine) {
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptWarningMessage(appendArguments(context));
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::error(QScriptContext* context, QScriptEngine* engine) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptErrorMessage(appendArguments(context));
+ScriptValue ConsoleScriptingInterface::error(ScriptContext* context, ScriptEngine* engine) {
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptErrorMessage(appendArguments(context));
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::exception(QScriptContext* context, QScriptEngine* engine) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptErrorMessage(appendArguments(context));
+ScriptValue ConsoleScriptingInterface::exception(ScriptContext* context, ScriptEngine* engine) {
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptErrorMessage(appendArguments(context));
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
 void ConsoleScriptingInterface::time(QString labelName) {
     _timerDetails.insert(labelName, QDateTime::currentDateTime().toUTC());
     QString message = QString("%1: Timer started").arg(labelName);
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->scriptPrintedMessage(message);
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->scriptPrintedMessage(message);
     }
 }
 
 void ConsoleScriptingInterface::timeEnd(QString labelName) {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
+    if (ScriptManager* scriptManager = engine()->manager()) {
         if (!_timerDetails.contains(labelName)) {
-            scriptEngine->scriptErrorMessage("No such label found " + labelName);
+            scriptManager->scriptErrorMessage("No such label found " + labelName);
             return;
         }
 
         if (_timerDetails.value(labelName).isNull()) {
             _timerDetails.remove(labelName);
-            scriptEngine->scriptErrorMessage("Invalid start time for " + labelName);
+            scriptManager->scriptErrorMessage("Invalid start time for " + labelName);
             return;
         }
         QDateTime _startTime = _timerDetails.value(labelName);
@@ -101,11 +104,11 @@ void ConsoleScriptingInterface::timeEnd(QString labelName) {
         QString message = QString("%1: %2ms").arg(labelName).arg(QString::number(diffInMS));
         _timerDetails.remove(labelName);
 
-        scriptEngine->scriptPrintedMessage(message);
+        scriptManager->scriptPrintedMessage(message);
     }
 }
 
-QScriptValue ConsoleScriptingInterface::assertion(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue ConsoleScriptingInterface::assertion(ScriptContext* context, ScriptEngine* engine) {
     QString message;
     bool condition = false;
     for (int i = 0; i < context->argumentCount(); i++) {
@@ -123,45 +126,46 @@ QScriptValue ConsoleScriptingInterface::assertion(QScriptContext* context, QScri
         } else {
             assertionResult = QString("Assertion failed : %1").arg(message);
         }
-        if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-            scriptEngine->scriptErrorMessage(assertionResult);
+        if (ScriptManager* scriptManager = engine->manager()) {
+            scriptManager->scriptErrorMessage(assertionResult);
         }
     }
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
 void ConsoleScriptingInterface::trace() {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->scriptPrintedMessage
+    ScriptEnginePointer scriptEngine = engine();
+    if (ScriptManager* scriptManager = scriptEngine->manager()) {
+        scriptManager->scriptPrintedMessage
             (QString(STACK_TRACE_FORMAT).arg(LINE_SEPARATOR,
             scriptEngine->currentContext()->backtrace().join(LINE_SEPARATOR)));
     }
 }
 
 void ConsoleScriptingInterface::clear() {
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->clearDebugLogWindow();
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->clearDebugLogWindow();
     }
 }
 
-QScriptValue ConsoleScriptingInterface::group(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue ConsoleScriptingInterface::group(ScriptContext* context, ScriptEngine* engine) {
     logGroupMessage(context->argument(0).toString(), engine); // accept first parameter as label
     _groupDetails.push_back(context->argument(0).toString());
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::groupCollapsed(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue ConsoleScriptingInterface::groupCollapsed(ScriptContext* context, ScriptEngine* engine) {
     logGroupMessage(context->argument(0).toString(), engine); // accept first parameter as label
     _groupDetails.push_back(context->argument(0).toString());
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QScriptValue ConsoleScriptingInterface::groupEnd(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue ConsoleScriptingInterface::groupEnd(ScriptContext* context, ScriptEngine* engine) {
     ConsoleScriptingInterface::_groupDetails.removeLast();
-    return QScriptValue::NullValue;
+    return engine->nullValue();
 }
 
-QString ConsoleScriptingInterface::appendArguments(QScriptContext* context) {
+QString ConsoleScriptingInterface::appendArguments(ScriptContext* context) {
     QString message;
     for (int i = 0; i < context->argumentCount(); i++) {
         if (i > 0) {
@@ -172,14 +176,14 @@ QString ConsoleScriptingInterface::appendArguments(QScriptContext* context) {
     return message;
 }
 
-void ConsoleScriptingInterface::logGroupMessage(QString message, QScriptEngine* engine) {
+void ConsoleScriptingInterface::logGroupMessage(QString message, ScriptEngine* engine) {
     int _addSpaces = _groupDetails.count() * INDENTATION;
     QString logMessage;
     for (int i = 0; i < _addSpaces; i++) {
         logMessage.append(SPACE_SEPARATOR);
     }
     logMessage.append(message);
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine)) {
-        scriptEngine->scriptPrintedMessage(logMessage);
+    if (ScriptManager* scriptManager = engine->manager()) {
+        scriptManager->scriptPrintedMessage(logMessage);
     }
 }
diff --git a/libraries/script-engine/src/ConsoleScriptingInterface.h b/libraries/script-engine/src/ConsoleScriptingInterface.h
index 591d44b22d1..09a44259c5f 100644
--- a/libraries/script-engine/src/ConsoleScriptingInterface.h
+++ b/libraries/script-engine/src/ConsoleScriptingInterface.h
@@ -27,7 +27,12 @@
 #include <QtCore/QDateTime>
 #include <QtCore/QList>
 #include <QtCore/QHash>
-#include <QtScript/QScriptable>
+
+#include "Scriptable.h"
+#include "ScriptValue.h"
+
+class ScriptContext;
+class ScriptEngine;
 
 /*@jsdoc
  * The <code>console</code> API provides program logging facilities.
@@ -41,7 +46,7 @@
  * @hifi-assignment-client
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/console.html">console</a></code> scripting API
-class ConsoleScriptingInterface : public QObject, protected QScriptable {
+class ConsoleScriptingInterface : public QObject, protected Scriptable {
     Q_OBJECT
 public:
 
@@ -51,7 +56,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.info
      * @param {...*} [message] - The message values to log.
      */
-    static QScriptValue info(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue info(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs a message to the program log and triggers {@link Script.printedMessage}.
@@ -69,7 +74,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * // string 7 true
      * // INFO - Console.log message: "string 7 true" in [console.js]
      */
-    static QScriptValue log(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue log(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs a message to the program log and triggers {@link Script.printedMessage}.
@@ -77,7 +82,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.debug
      * @param {...*} [message] - The message values to log.
      */
-    static QScriptValue debug(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue debug(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs a "WARNING" message to the program log and triggers {@link Script.warningMessage}.
@@ -85,7 +90,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.warn
      * @param {...*} [message] - The message values to log.
      */
-    static QScriptValue warn(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue warn(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs an "ERROR" message to the program log and triggers {@link Script.errorMessage}.
@@ -93,7 +98,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.error
      * @param {...*} [message] - The message values to log.
      */
-    static QScriptValue error(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue error(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * A synonym of {@link console.error}.
@@ -102,7 +107,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.exception
      * @param {...*} [message] - The message values to log.
      */
-    static QScriptValue exception(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue exception(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs an "ERROR" message to the program log and triggers {@link Script.errorMessage}, if a test condition fails.
@@ -125,7 +130,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * // INFO - Script continues running.
      */
     // Note: Is registered in the script engine as "assert"
-    static QScriptValue assertion(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue assertion(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Logs a message to the program log and triggers {@link Script.printedMessage}, then starts indenting subsequent 
@@ -153,7 +158,7 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * //   Sentence 5
      * //Sentence 6
      */
-    static QScriptValue group(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue group(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Has the same behavior as {@link console.group}.
@@ -162,13 +167,13 @@ class ConsoleScriptingInterface : public QObject, protected QScriptable {
      * @function console.groupCollapsed
      * @param {*} message - The message value to log.
      */
-    static QScriptValue groupCollapsed(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue groupCollapsed(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * Finishes a group of indented {@link console.log} messages.
      * @function console.groupEnd
      */
-    static QScriptValue groupEnd(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue groupEnd(ScriptContext* context, ScriptEngine* engine);
 
 public slots:
     
@@ -218,8 +223,8 @@ public slots:
 private:    
     QHash<QString, QDateTime> _timerDetails;
     static QList<QString> _groupDetails;
-    static void logGroupMessage(QString message, QScriptEngine* engine);
-    static QString appendArguments(QScriptContext* context);
+    static void logGroupMessage(QString message, ScriptEngine* engine);
+    static QString appendArguments(ScriptContext* context);
 };
 
 #endif // hifi_ConsoleScriptingInterface_h
diff --git a/libraries/entities/src/EntitiesScriptEngineProvider.h b/libraries/script-engine/src/EntitiesScriptEngineProvider.h
similarity index 96%
rename from libraries/entities/src/EntitiesScriptEngineProvider.h
rename to libraries/script-engine/src/EntitiesScriptEngineProvider.h
index 100c17df5f3..fffdbe4c766 100644
--- a/libraries/entities/src/EntitiesScriptEngineProvider.h
+++ b/libraries/script-engine/src/EntitiesScriptEngineProvider.h
@@ -1,6 +1,6 @@
 //
 //  EntitiesScriptEngineProvider.h
-//  libraries/entities/src
+//  libraries/script-engine/src
 //
 //  Created by Brad Hefta-Gaub on Sept. 18, 2015
 //  Copyright 2015 High Fidelity, Inc.
diff --git a/libraries/networking/src/EntityScriptClient.cpp b/libraries/script-engine/src/EntityScriptClient.cpp
similarity index 99%
rename from libraries/networking/src/EntityScriptClient.cpp
rename to libraries/script-engine/src/EntityScriptClient.cpp
index fb98e8042bb..93406da9531 100644
--- a/libraries/networking/src/EntityScriptClient.cpp
+++ b/libraries/script-engine/src/EntityScriptClient.cpp
@@ -1,6 +1,6 @@
 #include "EntityScriptClient.h"
-#include "NodeList.h"
-#include "NetworkLogging.h"
+#include <NodeList.h>
+#include <NetworkLogging.h>
 #include "EntityScriptUtils.h"
 
 #include <QThread>
diff --git a/libraries/networking/src/EntityScriptClient.h b/libraries/script-engine/src/EntityScriptClient.h
similarity index 94%
rename from libraries/networking/src/EntityScriptClient.h
rename to libraries/script-engine/src/EntityScriptClient.h
index 1fddc6b9767..e8eedbb9d0a 100644
--- a/libraries/networking/src/EntityScriptClient.h
+++ b/libraries/script-engine/src/EntityScriptClient.h
@@ -1,6 +1,6 @@
 //
 //  EntityScriptClient.h
-//  libraries/networking/src
+//  libraries/script-engine/src
 //
 //  Created by Ryan Huffman on 2017/01/13
 //  Copyright 2017 High Fidelity, Inc.
@@ -14,10 +14,10 @@
 
 #include <QtCore/QSharedPointer>
 
-#include "ClientServerUtils.h"
-#include "LimitedNodeList.h"
-#include "ReceivedMessage.h"
-#include "AssetUtils.h"
+#include <ClientServerUtils.h>
+#include <LimitedNodeList.h>
+#include <ReceivedMessage.h>
+#include <AssetUtils.h>
 #include "EntityScriptUtils.h"
 
 #include <DependencyManager.h>
diff --git a/libraries/networking/src/EntityScriptUtils.h b/libraries/script-engine/src/EntityScriptUtils.h
similarity index 96%
rename from libraries/networking/src/EntityScriptUtils.h
rename to libraries/script-engine/src/EntityScriptUtils.h
index 15b056f0d24..4dad88f8924 100644
--- a/libraries/networking/src/EntityScriptUtils.h
+++ b/libraries/script-engine/src/EntityScriptUtils.h
@@ -1,6 +1,6 @@
 //
 //  EntityScriptUtils.h
-//  libraries/networking/src
+//  libraries/script-engine/src
 //
 //  Created by Ryan Huffman on 2017/01/13
 //  Copyright 2017 High Fidelity, Inc.
diff --git a/libraries/script-engine/src/EventTypes.cpp b/libraries/script-engine/src/EventTypes.cpp
index 94c074d44e1..2715d6252b5 100644
--- a/libraries/script-engine/src/EventTypes.cpp
+++ b/libraries/script-engine/src/EventTypes.cpp
@@ -13,16 +13,18 @@
 
 #include "KeyEvent.h"
 #include "MouseEvent.h"
-#include "SpatialEvent.h"
 #include "PointerEvent.h"
+#include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "SpatialEvent.h"
 #include "TouchEvent.h"
 #include "WheelEvent.h"
 
-void registerEventTypes(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, KeyEvent::toScriptValue, KeyEvent::fromScriptValue);
-    qScriptRegisterMetaType(engine, MouseEvent::toScriptValue, MouseEvent::fromScriptValue);
-    qScriptRegisterMetaType(engine, PointerEvent::toScriptValue, PointerEvent::fromScriptValue);
-    qScriptRegisterMetaType(engine, TouchEvent::toScriptValue, TouchEvent::fromScriptValue);
-    qScriptRegisterMetaType(engine, WheelEvent::toScriptValue, WheelEvent::fromScriptValue);
-    qScriptRegisterMetaType(engine, SpatialEvent::toScriptValue, SpatialEvent::fromScriptValue);
+void registerEventTypes(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, KeyEvent::toScriptValue, KeyEvent::fromScriptValue);
+    scriptRegisterMetaType(engine, MouseEvent::toScriptValue, MouseEvent::fromScriptValue);
+    scriptRegisterMetaType(engine, PointerEvent::toScriptValue, PointerEvent::fromScriptValue);
+    scriptRegisterMetaType(engine, TouchEvent::toScriptValue, TouchEvent::fromScriptValue);
+    scriptRegisterMetaType(engine, WheelEvent::toScriptValue, WheelEvent::fromScriptValue);
+    scriptRegisterMetaType(engine, SpatialEvent::toScriptValue, SpatialEvent::fromScriptValue);
 }
diff --git a/libraries/script-engine/src/EventTypes.h b/libraries/script-engine/src/EventTypes.h
index 052d736d489..118a765b17a 100644
--- a/libraries/script-engine/src/EventTypes.h
+++ b/libraries/script-engine/src/EventTypes.h
@@ -15,9 +15,9 @@
 #ifndef hifi_EventTypes_h
 #define hifi_EventTypes_h
 
-#include <QScriptEngine>
+class ScriptEngine;
 
-void registerEventTypes(QScriptEngine* engine);
+void registerEventTypes(ScriptEngine* engine);
 
 #endif // hifi_EventTypes_h
 
diff --git a/libraries/script-engine/src/KeyEvent.cpp b/libraries/script-engine/src/KeyEvent.cpp
index b565b1f3aa9..1c60ba7e1e6 100644
--- a/libraries/script-engine/src/KeyEvent.cpp
+++ b/libraries/script-engine/src/KeyEvent.cpp
@@ -12,9 +12,10 @@
 #include "KeyEvent.h"
 
 #include <qdebug.h>
-#include <qscriptengine.h>
 
 #include "ScriptEngineLogging.h"
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
 
 KeyEvent::KeyEvent() :
     key(0),
@@ -173,8 +174,8 @@ KeyEvent::operator QKeySequence() const {
  *     print(JSON.stringify(event));
  * });
  */
-QScriptValue KeyEvent::toScriptValue(QScriptEngine* engine, const KeyEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue KeyEvent::toScriptValue(ScriptEngine* engine, const KeyEvent& event) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("key", event.key);
     obj.setProperty("text", event.text);
     obj.setProperty("isShifted", event.isShifted);
@@ -186,7 +187,7 @@ QScriptValue KeyEvent::toScriptValue(QScriptEngine* engine, const KeyEvent& even
     return obj;
 }
 
-void KeyEvent::fromScriptValue(const QScriptValue& object, KeyEvent& event) {
+bool KeyEvent::fromScriptValue(const ScriptValue& object, KeyEvent& event) {
     
     event.isValid = false; // assume the worst
     event.isMeta = object.property("isMeta").toVariant().toBool();
@@ -195,13 +196,13 @@ void KeyEvent::fromScriptValue(const QScriptValue& object, KeyEvent& event) {
     event.isKeypad = object.property("isKeypad").toVariant().toBool();
     event.isAutoRepeat = object.property("isAutoRepeat").toVariant().toBool();
     
-    QScriptValue key = object.property("key");
+    ScriptValue key = object.property("key");
     if (key.isValid()) {
         event.key = key.toVariant().toInt();
         event.text = QString(QChar(event.key));
         event.isValid = true;
     } else {
-        QScriptValue text = object.property("text");
+        ScriptValue text = object.property("text");
         if (text.isValid()) {
             event.text = object.property("text").toVariant().toString();
             
@@ -280,9 +281,10 @@ void KeyEvent::fromScriptValue(const QScriptValue& object, KeyEvent& event) {
             }
             event.isValid = true;
         }
+        return true;
     }
     
-    QScriptValue isShifted = object.property("isShifted");
+    ScriptValue isShifted = object.property("isShifted");
     if (isShifted.isValid()) {
         event.isShifted = isShifted.toVariant().toBool();
     } else {
diff --git a/libraries/script-engine/src/KeyEvent.h b/libraries/script-engine/src/KeyEvent.h
index 10c5fde404d..ceccf86336f 100644
--- a/libraries/script-engine/src/KeyEvent.h
+++ b/libraries/script-engine/src/KeyEvent.h
@@ -16,7 +16,10 @@
 #define hifi_KeyEvent_h
 
 #include <QKeyEvent>
-#include <QScriptValue>
+
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a keyboard event to the scripting engine. Exposed as <code><a href="https://apidocs.vircadia.dev/global.html#KeyEvent">KeyEvent</a></code>
 class KeyEvent {
@@ -26,8 +29,8 @@ class KeyEvent {
     bool operator==(const KeyEvent& other) const;
     operator QKeySequence() const;
     
-    static QScriptValue toScriptValue(QScriptEngine* engine, const KeyEvent& event);
-    static void fromScriptValue(const QScriptValue& object, KeyEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const KeyEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, KeyEvent& event);
     
     int key;
     QString text;
diff --git a/libraries/networking/src/LocationScriptingInterface.cpp b/libraries/script-engine/src/LocationScriptingInterface.cpp
similarity index 70%
rename from libraries/networking/src/LocationScriptingInterface.cpp
rename to libraries/script-engine/src/LocationScriptingInterface.cpp
index 39845558a8a..505af4bbefc 100644
--- a/libraries/networking/src/LocationScriptingInterface.cpp
+++ b/libraries/script-engine/src/LocationScriptingInterface.cpp
@@ -1,6 +1,6 @@
 //
 //  LocationScriptingInterface.cpp
-//  libraries/networking/src
+//  libraries/script-engine/src
 //
 //  Created by Ryan Huffman on 4/29/14.
 //  Copyright 2014 High Fidelity, Inc.
@@ -11,23 +11,26 @@
 
 #include "LocationScriptingInterface.h"
 
-#include "AddressManager.h"
+#include <AddressManager.h>
+#include "ScriptContext.h"
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
 
 LocationScriptingInterface* LocationScriptingInterface::getInstance() {
     static LocationScriptingInterface sharedInstance;
     return &sharedInstance;
 }
 
-QScriptValue LocationScriptingInterface::locationGetter(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue LocationScriptingInterface::locationGetter(ScriptContext* context, ScriptEngine* engine) {
     return engine->newQObject(DependencyManager::get<AddressManager>().data());
 }
 
-QScriptValue LocationScriptingInterface::locationSetter(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue LocationScriptingInterface::locationSetter(ScriptContext* context, ScriptEngine* engine) {
     const QVariant& argumentVariant = context->argument(0).toVariant();
     
     // just try and convert the argument to a string, should be a hifi:// address
     QMetaObject::invokeMethod(DependencyManager::get<AddressManager>().data(), "handleLookupString",
                               Q_ARG(const QString&, argumentVariant.toString()));
     
-    return QScriptValue::UndefinedValue;
+    return engine->undefinedValue();
 }
diff --git a/libraries/networking/src/LocationScriptingInterface.h b/libraries/script-engine/src/LocationScriptingInterface.h
similarity index 68%
rename from libraries/networking/src/LocationScriptingInterface.h
rename to libraries/script-engine/src/LocationScriptingInterface.h
index 987c4ccd0d3..0f7f4ded18c 100644
--- a/libraries/networking/src/LocationScriptingInterface.h
+++ b/libraries/script-engine/src/LocationScriptingInterface.h
@@ -1,6 +1,6 @@
 //
 //  LocationScriptingInterface.h
-//  libraries/networking/src
+//  libraries/script-engine/src
 //
 //  Created by Ryan Huffman on 4/29/14.
 //  Copyright 2014 High Fidelity, Inc.
@@ -12,15 +12,18 @@
 #ifndef hifi_LocationScriptingInterface_h
 #define hifi_LocationScriptingInterface_h
 
-#include <qscriptengine.h>
+#include "ScriptValue.h"
+
+class ScriptContext;
+class ScriptEngine;
 
 class LocationScriptingInterface : public QObject {
     Q_OBJECT
 public:
     static LocationScriptingInterface* getInstance();
 
-    static QScriptValue locationGetter(QScriptContext* context, QScriptEngine* engine);
-    static QScriptValue locationSetter(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue locationGetter(ScriptContext* context, ScriptEngine* engine);
+    static ScriptValue locationSetter(ScriptContext* context, ScriptEngine* engine);
 private:
     LocationScriptingInterface() {};
 };
diff --git a/libraries/script-engine/src/MIDIEvent.cpp b/libraries/script-engine/src/MIDIEvent.cpp
index b32c5d9d87e..2070e7bbc9c 100644
--- a/libraries/script-engine/src/MIDIEvent.cpp
+++ b/libraries/script-engine/src/MIDIEvent.cpp
@@ -11,8 +11,14 @@
 
 #include "MIDIEvent.h"
 
-void registerMIDIMetaTypes(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, midiEventToScriptValue, midiEventFromScriptValue);
+#include <QtCore/QVariant>
+
+#include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "ScriptValue.h"
+
+void registerMIDIMetaTypes(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, midiEventToScriptValue, midiEventFromScriptValue);
 }
 
 const QString MIDI_DELTA_TIME_PROP_NAME = "deltaTime";
@@ -20,8 +26,8 @@ const QString MIDI_EVENT_TYPE_PROP_NAME = "type";
 const QString MIDI_DATA_1_PROP_NAME = "data1";
 const QString MIDI_DATA_2_PROP_NAME = "data2";
 
-QScriptValue midiEventToScriptValue(QScriptEngine* engine, const MIDIEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue midiEventToScriptValue(ScriptEngine* engine, const MIDIEvent& event) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty(MIDI_DELTA_TIME_PROP_NAME, event.deltaTime);
     obj.setProperty(MIDI_EVENT_TYPE_PROP_NAME, event.type);
     obj.setProperty(MIDI_DATA_1_PROP_NAME, event.data1);
@@ -29,9 +35,10 @@ QScriptValue midiEventToScriptValue(QScriptEngine* engine, const MIDIEvent& even
     return obj;
 }
 
-void midiEventFromScriptValue(const QScriptValue &object, MIDIEvent& event) {
+bool midiEventFromScriptValue(const ScriptValue &object, MIDIEvent& event) {
     event.deltaTime = object.property(MIDI_DELTA_TIME_PROP_NAME).toVariant().toDouble();
     event.type = object.property(MIDI_EVENT_TYPE_PROP_NAME).toVariant().toUInt();
     event.data1 = object.property(MIDI_DATA_1_PROP_NAME).toVariant().toUInt();
     event.data2 = object.property(MIDI_DATA_2_PROP_NAME).toVariant().toUInt();
+    return true;
 }
\ No newline at end of file
diff --git a/libraries/script-engine/src/MIDIEvent.h b/libraries/script-engine/src/MIDIEvent.h
index fd8f83d9cba..46b1ffb8eea 100644
--- a/libraries/script-engine/src/MIDIEvent.h
+++ b/libraries/script-engine/src/MIDIEvent.h
@@ -15,7 +15,9 @@
 #ifndef hifi_MIDIEvent_h
 #define hifi_MIDIEvent_h
 
-#include <QtScript/QScriptEngine>
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a MIDI protocol event to the scripting engine.
 class MIDIEvent {
@@ -28,10 +30,10 @@ class MIDIEvent {
 
 Q_DECLARE_METATYPE(MIDIEvent)
 
-void registerMIDIMetaTypes(QScriptEngine* engine);
+void registerMIDIMetaTypes(ScriptEngine* engine);
 
-QScriptValue midiEventToScriptValue(QScriptEngine* engine, const MIDIEvent& event);
-void midiEventFromScriptValue(const QScriptValue &object, MIDIEvent& event);
+ScriptValue midiEventToScriptValue(ScriptEngine* engine, const MIDIEvent& event);
+bool midiEventFromScriptValue(const ScriptValue &object, MIDIEvent& event);
 
 #endif // hifi_MIDIEvent_h
 
diff --git a/libraries/script-engine/src/Mat4.cpp b/libraries/script-engine/src/Mat4.cpp
index d4d73a46ccd..755744777da 100644
--- a/libraries/script-engine/src/Mat4.cpp
+++ b/libraries/script-engine/src/Mat4.cpp
@@ -20,6 +20,7 @@
 
 #include "ScriptEngineLogging.h"
 #include "ScriptEngine.h"
+#include "ScriptManager.h"
 
 glm::mat4 Mat4::multiply(const glm::mat4& m1, const glm::mat4& m2) const {
     return m1 * m2;
@@ -87,7 +88,7 @@ void Mat4::print(const QString& label, const glm::mat4& m, bool transpose) const
     QString message = QString("%1 %2").arg(qPrintable(label));
     message = message.arg(glm::to_string(out).c_str());
     qCDebug(scriptengine) << message;
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->print(message);
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->print(message);
     }
 }
diff --git a/libraries/script-engine/src/Mat4.h b/libraries/script-engine/src/Mat4.h
index 204e87c57db..85b499724f5 100644
--- a/libraries/script-engine/src/Mat4.h
+++ b/libraries/script-engine/src/Mat4.h
@@ -19,10 +19,10 @@
 
 #include <QObject>
 #include <QString>
-#include <QtScript/QScriptable>
 #include <QVector>
 #include <glm/glm.hpp>
 #include "RegisteredMetaTypes.h"
+#include "Scriptable.h"
 
 /*@jsdoc
  * The <code>Mat4</code> API provides facilities for generating and using 4 x 4 matrices. These matrices are typically used to 
@@ -39,7 +39,7 @@
  * @hifi-assignment-client
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Mat4.html">Mat4</a></code> scripting interface
-class Mat4 : public QObject, protected QScriptable {
+class Mat4 : public QObject, protected Scriptable {
     Q_OBJECT
 
 public slots:
diff --git a/libraries/script-engine/src/MenuItemProperties.cpp b/libraries/script-engine/src/MenuItemProperties.cpp
index bff1609db56..f25d05ddf99 100644
--- a/libraries/script-engine/src/MenuItemProperties.cpp
+++ b/libraries/script-engine/src/MenuItemProperties.cpp
@@ -14,6 +14,9 @@
 #include <QDebug>
 #include <RegisteredMetaTypes.h>
 
+#include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "ScriptValue.h"
 
 MenuItemProperties::MenuItemProperties(const QString& menuName, const QString& menuItemName,
                         const QString& shortcutKey, bool checkable, bool checked, bool separator) :
@@ -40,12 +43,12 @@ MenuItemProperties::MenuItemProperties(const QString& menuName, const QString& m
 {
 }
 
-void registerMenuItemProperties(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, menuItemPropertiesToScriptValue, menuItemPropertiesFromScriptValue);
+void registerMenuItemProperties(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, menuItemPropertiesToScriptValue, menuItemPropertiesFromScriptValue);
 }
 
-QScriptValue menuItemPropertiesToScriptValue(QScriptEngine* engine, const MenuItemProperties& properties) {
-    QScriptValue obj = engine->newObject();
+ScriptValue menuItemPropertiesToScriptValue(ScriptEngine* engine, const MenuItemProperties& properties) {
+    ScriptValue obj = engine->newObject();
     // not supported
     return obj;
 }
@@ -70,7 +73,7 @@ QScriptValue menuItemPropertiesToScriptValue(QScriptEngine* engine, const MenuIt
  * @property {string} [afterItem] - The name of the menu item to place this menu item after.
  * @property {string} [grouping] - The name of grouping to add this menu item to.
  */
-void menuItemPropertiesFromScriptValue(const QScriptValue& object, MenuItemProperties& properties) {
+bool menuItemPropertiesFromScriptValue(const ScriptValue& object, MenuItemProperties& properties) {
     properties.menuName = object.property("menuName").toVariant().toString();
     properties.menuItemName = object.property("menuItemName").toVariant().toString();
     properties.isCheckable = object.property("isCheckable").toVariant().toBool();
@@ -78,12 +81,12 @@ void menuItemPropertiesFromScriptValue(const QScriptValue& object, MenuItemPrope
     properties.isSeparator = object.property("isSeparator").toVariant().toBool();
 
     // handle the shortcut key options in order...
-    QScriptValue shortcutKeyValue = object.property("shortcutKey");
+    ScriptValue shortcutKeyValue = object.property("shortcutKey");
     if (shortcutKeyValue.isValid()) {
         properties.shortcutKey = shortcutKeyValue.toVariant().toString();
         properties.shortcutKeySequence = properties.shortcutKey;
     } else {
-        QScriptValue shortcutKeyEventValue = object.property("shortcutKeyEvent");
+        ScriptValue shortcutKeyEventValue = object.property("shortcutKeyEvent");
         if (shortcutKeyEventValue.isValid()) {
             KeyEvent::fromScriptValue(shortcutKeyEventValue, properties.shortcutKeyEvent);
             properties.shortcutKeySequence = properties.shortcutKeyEvent;
@@ -96,6 +99,7 @@ void menuItemPropertiesFromScriptValue(const QScriptValue& object, MenuItemPrope
     properties.beforeItem = object.property("beforeItem").toVariant().toString();
     properties.afterItem = object.property("afterItem").toVariant().toString();
     properties.grouping = object.property("grouping").toVariant().toString();
+    return true;
 }
 
 
diff --git a/libraries/script-engine/src/MenuItemProperties.h b/libraries/script-engine/src/MenuItemProperties.h
index 30b78cd55bc..2cdfbad142a 100644
--- a/libraries/script-engine/src/MenuItemProperties.h
+++ b/libraries/script-engine/src/MenuItemProperties.h
@@ -15,10 +15,11 @@
 #ifndef hifi_MenuItemProperties_h
 #define hifi_MenuItemProperties_h
 
-#include <QtScript/QScriptEngine>
-
 #include "KeyEvent.h"
 
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a menu item a script may declare and bind events to. Exposed as <code><a href="https://apidocs.vircadia.dev/Menu.html#.MenuItemProperties">MenuItemProperties</a></code>
 class MenuItemProperties {
@@ -53,9 +54,9 @@ class MenuItemProperties {
     static const int UNSPECIFIED_POSITION = -1;
 };
 Q_DECLARE_METATYPE(MenuItemProperties)
-QScriptValue menuItemPropertiesToScriptValue(QScriptEngine* engine, const MenuItemProperties& props);
-void menuItemPropertiesFromScriptValue(const QScriptValue& object, MenuItemProperties& props);
-void registerMenuItemProperties(QScriptEngine* engine);
+ScriptValue menuItemPropertiesToScriptValue(ScriptEngine* engine, const MenuItemProperties& props);
+bool menuItemPropertiesFromScriptValue(const ScriptValue& object, MenuItemProperties& props);
+void registerMenuItemProperties(ScriptEngine* engine);
 
 
 
diff --git a/libraries/script-engine/src/MouseEvent.cpp b/libraries/script-engine/src/MouseEvent.cpp
index 6adb39a29bd..a0726e0aedf 100644
--- a/libraries/script-engine/src/MouseEvent.cpp
+++ b/libraries/script-engine/src/MouseEvent.cpp
@@ -11,8 +11,8 @@
 
 #include "MouseEvent.h"
 
-#include <qscriptengine.h>
-#include <qscriptvalue.h>
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
 
 MouseEvent::MouseEvent() :
     x(0.0f),
@@ -86,8 +86,8 @@ MouseEvent::MouseEvent(const QMouseEvent& event) :
  *     print(JSON.stringify(event));
  * });
  */
-QScriptValue MouseEvent::toScriptValue(QScriptEngine* engine, const MouseEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue MouseEvent::toScriptValue(ScriptEngine* engine, const MouseEvent& event) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("x", event.x);
     obj.setProperty("y", event.y);
     obj.setProperty("button", event.button);
@@ -102,6 +102,7 @@ QScriptValue MouseEvent::toScriptValue(QScriptEngine* engine, const MouseEvent&
     return obj;
 }
 
-void MouseEvent::fromScriptValue(const QScriptValue& object, MouseEvent& event) {
+bool MouseEvent::fromScriptValue(const ScriptValue& object, MouseEvent& event) {
     // nothing for now...
+    return false;
 }
diff --git a/libraries/script-engine/src/MouseEvent.h b/libraries/script-engine/src/MouseEvent.h
index 7c668a69014..ffbc25854c8 100644
--- a/libraries/script-engine/src/MouseEvent.h
+++ b/libraries/script-engine/src/MouseEvent.h
@@ -16,9 +16,10 @@
 #define hifi_MouseEvent_h
 
 #include <QMouseEvent>
-#include <QScriptValue>
 
-class QScriptEngine;
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a mouse event to the scripting engine. Exposed as <code><a href="https://apidocs.vircadia.dev/global.html#MouseEvent">MouseEvent</a></code>
 class MouseEvent {
@@ -26,10 +27,10 @@ class MouseEvent {
     MouseEvent();
     MouseEvent(const QMouseEvent& event);
     
-    static QScriptValue toScriptValue(QScriptEngine* engine, const MouseEvent& event);
-    static void fromScriptValue(const QScriptValue& object, MouseEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const MouseEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, MouseEvent& event);
 
-    QScriptValue toScriptValue(QScriptEngine* engine) const { return MouseEvent::toScriptValue(engine, *this); }
+    ScriptValue toScriptValue(ScriptEngine* engine) const { return MouseEvent::toScriptValue(engine, *this); }
     
     int x;
     int y;
diff --git a/libraries/shared/src/PointerEvent.cpp b/libraries/script-engine/src/PointerEvent.cpp
similarity index 93%
rename from libraries/shared/src/PointerEvent.cpp
rename to libraries/script-engine/src/PointerEvent.cpp
index be237442c01..8107640a876 100644
--- a/libraries/shared/src/PointerEvent.cpp
+++ b/libraries/script-engine/src/PointerEvent.cpp
@@ -11,10 +11,10 @@
 
 #include "PointerEvent.h"
 
-#include <qscriptengine.h>
-#include <qscriptvalue.h>
-
 #include "RegisteredMetaTypes.h"
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
+#include "ScriptValueUtils.h"
 
 static bool areFlagsSet(uint32_t flags, uint32_t mask) {
     return (flags & mask) != 0;
@@ -125,8 +125,8 @@ void PointerEvent::setButton(Button button) {
  * </table>
  * @typedef {number} KeyboardModifiers
  */
-QScriptValue PointerEvent::toScriptValue(QScriptEngine* engine, const PointerEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue PointerEvent::toScriptValue(ScriptEngine* engine, const PointerEvent& event) {
+    ScriptValue obj = engine->newObject();
 
     switch (event._type) {
     case Press:
@@ -146,24 +146,24 @@ QScriptValue PointerEvent::toScriptValue(QScriptEngine* engine, const PointerEve
 
     obj.setProperty("id", event._id);
 
-    QScriptValue pos2D = engine->newObject();
+    ScriptValue pos2D = engine->newObject();
     pos2D.setProperty("x", event._pos2D.x);
     pos2D.setProperty("y", event._pos2D.y);
     obj.setProperty("pos2D", pos2D);
 
-    QScriptValue pos3D = engine->newObject();
+    ScriptValue pos3D = engine->newObject();
     pos3D.setProperty("x", event._pos3D.x);
     pos3D.setProperty("y", event._pos3D.y);
     pos3D.setProperty("z", event._pos3D.z);
     obj.setProperty("pos3D", pos3D);
 
-    QScriptValue normal = engine->newObject();
+    ScriptValue normal = engine->newObject();
     normal.setProperty("x", event._normal.x);
     normal.setProperty("y", event._normal.y);
     normal.setProperty("z", event._normal.z);
     obj.setProperty("normal", normal);
 
-    QScriptValue direction = engine->newObject();
+    ScriptValue direction = engine->newObject();
     direction.setProperty("x", event._direction.x);
     direction.setProperty("y", event._direction.y);
     direction.setProperty("z", event._direction.z);
@@ -207,14 +207,14 @@ QScriptValue PointerEvent::toScriptValue(QScriptEngine* engine, const PointerEve
     obj.setProperty("isSecondaryHeld", areFlagsSet(event._buttons, SecondaryButton));
     obj.setProperty("isTertiaryHeld", areFlagsSet(event._buttons, TertiaryButton));
 
-    obj.setProperty("keyboardModifiers", QScriptValue(event.getKeyboardModifiers()));
+    obj.setProperty("keyboardModifiers", engine->newValue(event.getKeyboardModifiers()));
 
     return obj;
 }
 
-void PointerEvent::fromScriptValue(const QScriptValue& object, PointerEvent& event) {
+bool PointerEvent::fromScriptValue(const ScriptValue& object, PointerEvent& event) {
     if (object.isObject()) {
-        QScriptValue type = object.property("type");
+        ScriptValue type = object.property("type");
         QString typeStr = type.isString() ? type.toString() : "Move";
         if (typeStr == "Press") {
             event._type = Press;
@@ -226,7 +226,7 @@ void PointerEvent::fromScriptValue(const QScriptValue& object, PointerEvent& eve
             event._type = Move;
         }
 
-        QScriptValue id = object.property("id");
+        ScriptValue id = object.property("id");
         event._id = id.isNumber() ? (uint32_t)id.toNumber() : 0;
 
         vec2FromScriptValue(object.property("pos2D"), event._pos2D);
@@ -234,7 +234,7 @@ void PointerEvent::fromScriptValue(const QScriptValue& object, PointerEvent& eve
         vec3FromScriptValue(object.property("normal"), event._normal);
         vec3FromScriptValue(object.property("direction"), event._direction);
 
-        QScriptValue button = object.property("button");
+        ScriptValue button = object.property("button");
         QString buttonStr = type.isString() ? button.toString() : "NoButtons";
 
         if (buttonStr == "Primary") {
@@ -263,6 +263,7 @@ void PointerEvent::fromScriptValue(const QScriptValue& object, PointerEvent& eve
 
         event._keyboardModifiers = (Qt::KeyboardModifiers)(object.property("keyboardModifiers").toUInt32());
     }
+    return true;
 }
 
 static const char* typeToStringMap[PointerEvent::NumEventTypes] = { "Press", "DoublePress", "Release", "Move" };
diff --git a/libraries/shared/src/PointerEvent.h b/libraries/script-engine/src/PointerEvent.h
similarity index 87%
rename from libraries/shared/src/PointerEvent.h
rename to libraries/script-engine/src/PointerEvent.h
index 23f435a67c7..258cdd22e23 100644
--- a/libraries/shared/src/PointerEvent.h
+++ b/libraries/script-engine/src/PointerEvent.h
@@ -9,6 +9,9 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
+/// @addtogroup ScriptEngine
+/// @{
+
 #ifndef hifi_PointerEvent_h
 #define hifi_PointerEvent_h
 
@@ -16,8 +19,12 @@
 
 #include <stdint.h>
 #include <glm/glm.hpp>
-#include <QScriptValue>
 
+#include "ScriptValue.h"
+
+class ScriptEngine;
+
+/// Represents a 2D or 3D pointer to the scripting engine. Exposed as <code><a href="https://apidocs.vircadia.dev/global.html#PointerEvent">PointerEvent</a></code>
 class PointerEvent {
 public:
     enum Button {
@@ -44,10 +51,10 @@ class PointerEvent {
                  const glm::vec3& normal, const glm::vec3& direction,
                  Button button = NoButtons, uint32_t buttons = NoButtons, Qt::KeyboardModifiers keyboardModifiers = Qt::NoModifier);
 
-    static QScriptValue toScriptValue(QScriptEngine* engine, const PointerEvent& event);
-    static void fromScriptValue(const QScriptValue& object, PointerEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const PointerEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, PointerEvent& event);
 
-    QScriptValue toScriptValue(QScriptEngine* engine) const { return PointerEvent::toScriptValue(engine, *this); }
+    ScriptValue toScriptValue(ScriptEngine* engine) const { return PointerEvent::toScriptValue(engine, *this); }
 
     EventType getType() const { return _type; }
     uint32_t getID() const { return _id; }
@@ -91,3 +98,5 @@ QDebug& operator<<(QDebug& dbg, const PointerEvent& p);
 Q_DECLARE_METATYPE(PointerEvent)
 
 #endif // hifi_PointerEvent_h
+
+/// @}
diff --git a/libraries/script-engine/src/Quat.cpp b/libraries/script-engine/src/Quat.cpp
index 8335cb9adfc..724ad34416c 100644
--- a/libraries/script-engine/src/Quat.cpp
+++ b/libraries/script-engine/src/Quat.cpp
@@ -18,6 +18,7 @@
 
 #include "ScriptEngineLogging.h"
 #include "ScriptEngine.h"
+#include "ScriptManager.h"
 
 quat Quat::normalize(const glm::quat& q) {
     return glm::normalize(q);
@@ -123,8 +124,8 @@ void Quat::print(const QString& label, const glm::quat& q, bool asDegrees) {
         message = message.arg(glm::to_string(glm::dquat(q)).c_str());
     }
     qCDebug(scriptengine) << message;
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->print(message);
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->print(message);
     }
 }
 
diff --git a/libraries/script-engine/src/Quat.h b/libraries/script-engine/src/Quat.h
index cdda723ee09..d4d9967dac9 100644
--- a/libraries/script-engine/src/Quat.h
+++ b/libraries/script-engine/src/Quat.h
@@ -21,10 +21,11 @@
 
 #include <QObject>
 #include <QString>
-#include <QtScript/QScriptable>
 
 #include <GLMHelpers.h>
 
+#include "Scriptable.h"
+
 /*@jsdoc
  * A quaternion value. See also the {@link Quat(0)|Quat} API.
  * @typedef {object} Quat
@@ -55,7 +56,7 @@
  * print(JSON.stringify(Quat.safeEulerAngles(Quat.IDENTITY))); // { x: 0, y: 0, z: 0 }
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Quat.html">Quat</a></code> scripting interface
-class Quat : public QObject, protected QScriptable {
+class Quat : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(glm::quat IDENTITY READ IDENTITY CONSTANT)
 
diff --git a/libraries/script-engine/src/SceneScriptingInterface.h b/libraries/script-engine/src/SceneScriptingInterface.h
index e5cd0ed126c..69ac0c4ed7d 100644
--- a/libraries/script-engine/src/SceneScriptingInterface.h
+++ b/libraries/script-engine/src/SceneScriptingInterface.h
@@ -16,7 +16,6 @@
 #ifndef hifi_SceneScriptingInterface_h
 #define hifi_SceneScriptingInterface_h
 
-#include <qscriptengine.h>
 #include <DependencyManager.h>
 
 /*@jsdoc
diff --git a/libraries/script-engine/src/ScriptCache.cpp b/libraries/script-engine/src/ScriptCache.cpp
index 0b63803a333..bd2e5dfa781 100644
--- a/libraries/script-engine/src/ScriptCache.cpp
+++ b/libraries/script-engine/src/ScriptCache.cpp
@@ -22,6 +22,7 @@
 #include <QMetaEnum>
 
 #include <assert.h>
+#include <ResourceCache.h>
 #include <SharedUtil.h>
 
 #include "ScriptEngines.h"
diff --git a/libraries/script-engine/src/ScriptCache.h b/libraries/script-engine/src/ScriptCache.h
index 03d815e4ada..019cdac6f91 100644
--- a/libraries/script-engine/src/ScriptCache.h
+++ b/libraries/script-engine/src/ScriptCache.h
@@ -16,7 +16,7 @@
 #define hifi_ScriptCache_h
 
 #include <mutex>
-#include <ResourceCache.h>
+#include <DependencyManager.h>
 
 using contentAvailableCallback = std::function<void(const QString& scriptOrURL, const QString& contents, bool isURL, bool contentAvailable, const QString& status)>;
 
diff --git a/libraries/script-engine/src/ScriptContext.cpp b/libraries/script-engine/src/ScriptContext.cpp
new file mode 100644
index 00000000000..16b49fe7054
--- /dev/null
+++ b/libraries/script-engine/src/ScriptContext.cpp
@@ -0,0 +1,23 @@
+//
+//  ScriptContext.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 12/5/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptContext.h"
+
+#include "Scriptable.h"
+
+ScriptContextGuard::ScriptContextGuard(ScriptContext* context) {
+    _oldContext = Scriptable::context();
+    Scriptable::setContext(context);
+}
+
+ScriptContextGuard::~ScriptContextGuard() {
+    Scriptable::setContext(_oldContext);
+}
diff --git a/libraries/script-engine/src/ScriptContext.h b/libraries/script-engine/src/ScriptContext.h
new file mode 100644
index 00000000000..33c227b9a3e
--- /dev/null
+++ b/libraries/script-engine/src/ScriptContext.h
@@ -0,0 +1,81 @@
+//
+//  ScriptContext.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/1/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptContext_h
+#define hifi_ScriptContext_h
+
+#include <memory>
+
+#include <QtCore/QString>
+#include <QtCore/QStringList>
+
+#include "ScriptValue.h"
+
+class ScriptContext;
+class ScriptEngine;
+class ScriptFunctionContext;
+using ScriptContextPointer = std::shared_ptr<ScriptContext>;
+using ScriptFunctionContextPointer = std::shared_ptr<ScriptFunctionContext>;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptContextInfo
+class ScriptFunctionContext {
+public:
+    enum FunctionType {
+        ScriptFunction = 0,
+        QtFunction = 1,
+        QtPropertyFunction = 2,
+        NativeFunction = 3,
+    };
+    
+public:
+    virtual QString fileName() const = 0;
+    virtual QString functionName() const = 0;
+    virtual FunctionType functionType() const = 0;
+    virtual int lineNumber() const = 0;
+
+protected:
+    ~ScriptFunctionContext() {} // prevent explicit deletion of base class
+};
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptContext
+class ScriptContext {
+public:
+    virtual int argumentCount() const = 0;
+    virtual ScriptValue argument(int index) const = 0;
+    virtual QStringList backtrace() const = 0;
+    virtual ScriptValue callee() const = 0;
+    virtual ScriptEnginePointer engine() const = 0;
+    virtual ScriptFunctionContextPointer functionContext() const = 0;
+    virtual ScriptContextPointer parentContext() const = 0;
+    virtual ScriptValue thisObject() const = 0;
+    virtual ScriptValue throwError(const QString& text) = 0;
+    virtual ScriptValue throwValue(const ScriptValue& value) = 0;
+
+protected:
+    ~ScriptContext() {}  // prevent explicit deletion of base class
+};
+
+class ScriptContextGuard {
+public:
+    ScriptContextGuard(ScriptContext* context);
+    ~ScriptContextGuard();
+
+private:
+    ScriptContext* _oldContext;
+};
+
+#endif // hifi_ScriptContext_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index c1578265e3a..4bcac85e45a 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -4,6 +4,7 @@
 //
 //  Created by Brad Hefta-Gaub on 12/14/13.
 //  Copyright 2013 High Fidelity, Inc.
+//  Copyright 2020 Vircadia contributors.
 //
 //  Distributed under the Apache License, Version 2.0.
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
@@ -11,2834 +12,56 @@
 
 #include "ScriptEngine.h"
 
-#include <chrono>
-#include <thread>
-
-#include <QtCore/QCoreApplication>
-#include <QtCore/QEventLoop>
-#include <QtCore/QFileInfo>
-#include <QtCore/QTimer>
-#include <QtCore/QThread>
-#include <QtCore/QRegularExpression>
-
-#include <QtCore/QFuture>
-#include <QtConcurrent/QtConcurrentRun>
-
-#include <QtWidgets/QMainWindow>
-#include <QtWidgets/QApplication>
-#include <QtWidgets/QMenuBar>
-#include <QtWidgets/QMenu>
-
-#include <QtNetwork/QNetworkRequest>
-#include <QtNetwork/QNetworkReply>
-
-#include <QtScript/QScriptContextInfo>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptValueIterator>
-
-#include <shared/LocalFileAccessGate.h>
-#include <shared/QtHelpers.h>
-#include <shared/AbstractLoggerInterface.h>
-#include <AudioConstants.h>
-#include <AudioEffectOptions.h>
-#include <AvatarData.h>
-#include <DebugDraw.h>
-#include <EntityScriptingInterface.h>
-#include <MessagesClient.h>
-#include <NetworkAccessManager.h>
-#include <PathUtils.h>
-#include <ResourceScriptingInterface.h>
-#include <UserActivityLoggerScriptingInterface.h>
-#include <NodeList.h>
-#include <ScriptAvatarData.h>
-#include <udt/PacketHeaders.h>
-#include <UUID.h>
-
-#include <controllers/ScriptingInterface.h>
-#include <AnimationObject.h>
-
-#include "ArrayBufferViewClass.h"
-#include "AssetScriptingInterface.h"
-#include "BatchLoader.h"
-#include "BaseScriptEngine.h"
-#include "DataViewClass.h"
-#include "EventTypes.h"
-#include "FileScriptingInterface.h" // unzip project
-#include "MenuItemProperties.h"
-#include "ScriptAudioInjector.h"
-#include "ScriptAvatarData.h"
-#include "ScriptCache.h"
 #include "ScriptEngineLogging.h"
-#include "TypedArrays.h"
-#include "XMLHttpRequestClass.h"
-#include "WebSocketClass.h"
-#include "RecordingScriptingInterface.h"
-#include "ScriptEngines.h"
-#include "StackTestScriptingInterface.h"
-#include "ModelScriptingInterface.h"
-
-#include <Profile.h>
-
-#include "../../midi/src/Midi.h"        // FIXME why won't a simpler include work?
-#include "MIDIEvent.h"
-
-#include "SettingHandle.h"
-#include <AddressManager.h>
-#include <NetworkingConstants.h>
-#include <ThreadHelpers.h>
-
-const QString ScriptEngine::_SETTINGS_ENABLE_EXTENDED_EXCEPTIONS {
-    "com.highfidelity.experimental.enableExtendedJSExceptions"
-};
-
-static const int MAX_MODULE_ID_LENGTH { 4096 };
-static const int MAX_DEBUG_VALUE_LENGTH { 80 };
-
-static const QScriptEngine::QObjectWrapOptions DEFAULT_QOBJECT_WRAP_OPTIONS =
-                QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects;
-static const QScriptValue::PropertyFlags READONLY_PROP_FLAGS { QScriptValue::ReadOnly | QScriptValue::Undeletable };
-static const QScriptValue::PropertyFlags READONLY_HIDDEN_PROP_FLAGS { READONLY_PROP_FLAGS | QScriptValue::SkipInEnumeration };
-
-static const bool HIFI_AUTOREFRESH_FILE_SCRIPTS { true };
-
-Q_DECLARE_METATYPE(QScriptEngine::FunctionSignature)
-int functionSignatureMetaID = qRegisterMetaType<QScriptEngine::FunctionSignature>();
-
-int scriptEnginePointerMetaID = qRegisterMetaType<ScriptEnginePointer>();
-
-Q_DECLARE_METATYPE(ExternalResource::Bucket);
-
-static QScriptValue debugPrint(QScriptContext* context, QScriptEngine* engine) {
-    // assemble the message by concatenating our arguments
-    QString message = "";
-    for (int i = 0; i < context->argumentCount(); i++) {
-        if (i > 0) {
-            message += " ";
-        }
-        message += context->argument(i).toString();
-    }
-
-    // was this generated by a script engine? If we don't recognize it then send the message and exit
-    ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine);
-    if (!scriptEngine) {
-        qCDebug(scriptengine_script, "%s", qUtf8Printable(message));
-        return QScriptValue();
-    }
-
-    // This message was sent by one of our script engines, let's try to see if we can find the source.
-    // Note that the first entry in the backtrace should be "print" and is somewhat useless to us
-    AbstractLoggerInterface* loggerInterface = AbstractLoggerInterface::get();
-    if (loggerInterface && loggerInterface->showSourceDebugging()) {
-        QScriptContext* userContext = context;
-        while (userContext && QScriptContextInfo(userContext).functionType() == QScriptContextInfo::NativeFunction) {
-            userContext = userContext->parentContext();
-        }
-        QString location;
-        if (userContext) {
-            QScriptContextInfo contextInfo(userContext);
-            QString fileName = contextInfo.fileName();
-            int lineNumber = contextInfo.lineNumber();
-            QString functionName = contextInfo.functionName();
-    
-            location = functionName;
-            if (!fileName.isEmpty()) {
-                if (location.isEmpty()) {
-                    location = fileName;
-                } else {
-                    location = QString("%1 at %2").arg(location).arg(fileName);
-                }
-            }
-            if (lineNumber != -1) {
-                location = QString("%1:%2").arg(location).arg(lineNumber);
-            }
-        }
-        if (location.isEmpty()) {
-            location = scriptEngine->getFilename();
-        }
-    
-        // give the script engine a chance to notify the system about this message
-        scriptEngine->print(message);
-    
-        // send the message to debug log
-        qCDebug(scriptengine_script, "[%s] %s", qUtf8Printable(location), qUtf8Printable(message));
-    } else {
-        scriptEngine->print(message);
-        // prefix the script engine name to help disambiguate messages in the main debug log
-        qCDebug(scriptengine_script, "[%s] %s", qUtf8Printable(scriptEngine->getFilename()), qUtf8Printable(message));
-    }
-
-    return QScriptValue();
-}
-
-Q_DECLARE_METATYPE(controller::InputController*)
-//static int inputControllerPointerId = qRegisterMetaType<controller::InputController*>();
-
-QScriptValue inputControllerToScriptValue(QScriptEngine *engine, controller::InputController* const &in) {
-    return engine->newQObject(in, QScriptEngine::QtOwnership, DEFAULT_QOBJECT_WRAP_OPTIONS);
-}
-
-void inputControllerFromScriptValue(const QScriptValue &object, controller::InputController* &out) {
-    out = qobject_cast<controller::InputController*>(object.toQObject());
-}
-
-// FIXME Come up with a way to properly encode entity IDs in filename
-// The purpose of the following two function is to embed entity ids into entity script filenames
-// so that they show up in stacktraces
-//
-// Extract the url portion of a url that has been encoded with encodeEntityIdIntoEntityUrl(...)
-QString extractUrlFromEntityUrl(const QString& url) {
-    auto parts = url.split(' ', Qt::SkipEmptyParts);
-    if (parts.length() > 0) {
-        return parts[0];
-    } else {
-        return "";
-    }
-}
-
-// Encode an entity id into an entity url
-// Example: http://www.example.com/some/path.js [EntityID:{9fdd355f-d226-4887-9484-44432d29520e}]
-QString encodeEntityIdIntoEntityUrl(const QString& url, const QString& entityID) {
-    return url + " [EntityID:" + entityID + "]";
-}
-
-QString ScriptEngine::logException(const QScriptValue& exception) {
-    auto message = formatException(exception, _enableExtendedJSExceptions.get());
-    scriptErrorMessage(message);
-    return message;
-}
-
-ScriptEnginePointer scriptEngineFactory(ScriptEngine::Context context,
-                                                 const QString& scriptContents,
-                                                 const QString& fileNameString) {
-    ScriptEngine* engine = new ScriptEngine(context, scriptContents, fileNameString);
-    ScriptEnginePointer engineSP = ScriptEnginePointer(engine, &QObject::deleteLater);
-    auto scriptEngines = DependencyManager::get<ScriptEngines>();
-    scriptEngines->addScriptEngine(qSharedPointerCast<ScriptEngine>(engineSP));
-    engine->setScriptEngines(scriptEngines);
-    return engineSP;
-}
-
-int ScriptEngine::processLevelMaxRetries { ScriptRequest::MAX_RETRIES };
-ScriptEngine::ScriptEngine(Context context, const QString& scriptContents, const QString& fileNameString) :
-    BaseScriptEngine(),
-    _context(context),
-    _scriptContents(scriptContents),
-    _timerFunctionMap(),
-    _fileNameString(fileNameString),
-    _arrayBufferClass(new ArrayBufferClass(this)),
-    _assetScriptingInterface(new AssetScriptingInterface(this))
-{
-    switch (_context) {
-        case Context::CLIENT_SCRIPT:
-            _type = Type::CLIENT;
-            break;
-        case Context::ENTITY_CLIENT_SCRIPT:
-            _type = Type::ENTITY_CLIENT;
-            break;
-        case Context::ENTITY_SERVER_SCRIPT:
-            _type = Type::ENTITY_SERVER;
-            break;
-        case Context::AGENT_SCRIPT:
-            _type = Type::AGENT;
-            break;
-    }
-
-    connect(this, &QScriptEngine::signalHandlerException, this, [this](const QScriptValue& exception) {
-        if (hasUncaughtException()) {
-            // the engine's uncaughtException() seems to produce much better stack traces here
-            emit unhandledException(cloneUncaughtException("signalHandlerException"));
-            clearExceptions();
-        } else {
-            // ... but may not always be available -- so if needed we fallback to the passed exception
-            emit unhandledException(exception);
-        }
-    }, Qt::DirectConnection);
-
-    setProcessEventsInterval(MSECS_PER_SECOND);
-    if (isEntityServerScript()) {
-        qCDebug(scriptengine) << "isEntityServerScript() -- limiting maxRetries to 1";
-        processLevelMaxRetries = 1;
-    }
-
-    // this is where all unhandled exceptions end up getting logged
-    connect(this, &BaseScriptEngine::unhandledException, this, [this](const QScriptValue& err) {
-        auto output = err.engine() == this ? err : makeError(err);
-        if (!output.property("detail").isValid()) {
-            output.setProperty("detail", "UnhandledException");
-        }
-        logException(output);
-    });
-
-    if (_type == Type::ENTITY_CLIENT || _type == Type::ENTITY_SERVER) {
-        QObject::connect(this, &ScriptEngine::update, this, [this]() {
-            // process pending entity script content
-            if (!_contentAvailableQueue.empty() && !(_isFinished || _isStopping)) {
-                EntityScriptContentAvailableMap pending;
-                std::swap(_contentAvailableQueue, pending);
-                for (auto& pair : pending) {
-                    auto& args = pair.second;
-                    entityScriptContentAvailable(args.entityID, args.scriptOrURL, args.contents, args.isURL, args.success, args.status);
-                }
-            }
-        });
-    }
-}
-
-QString ScriptEngine::getTypeAsString() const {
-    auto value = QVariant::fromValue(_type).toString();
-    return value.isEmpty() ? "unknown" : value.toLower();
-}
-
-QString ScriptEngine::getContext() const {
-    switch (_context) {
-        case CLIENT_SCRIPT:
-            return "client";
-        case ENTITY_CLIENT_SCRIPT:
-            return "entity_client";
-        case ENTITY_SERVER_SCRIPT:
-            return "entity_server";
-        case AGENT_SCRIPT:
-            return "agent";
-        default:
-            return "unknown";
-    }
-    return "unknown";
-}
-
-bool ScriptEngine::isDebugMode() const {
-#if defined(DEBUG)
-    return true;
-#else
-    return false;
-#endif
-}
-
-ScriptEngine::~ScriptEngine() {}
-
-void ScriptEngine::disconnectNonEssentialSignals() {
-    disconnect();
-    QThread* workerThread;
-    // Ensure the thread should be running, and does exist
-    if (_isRunning && _isThreaded && (workerThread = thread())) {
-        connect(this, &QObject::destroyed, workerThread, &QThread::quit);
-        connect(workerThread, &QThread::finished, workerThread, &QObject::deleteLater);
-    }
-}
-
-void ScriptEngine::runInThread() {
-    Q_ASSERT_X(!_isThreaded, "ScriptEngine::runInThread()", "runInThread should not be called more than once");
-
-    if (_isThreaded) {
-        return;
-    }
-
-    _isThreaded = true;
-
-    // The thread interface cannot live on itself, and we want to move this into the thread, so
-    // the thread cannot have this as a parent.
-    QThread* workerThread = new QThread();
-    QString name = QString("js:") + getFilename().replace("about:","");
-    workerThread->setObjectName(name);
-    moveToThread(workerThread);
-
-    // NOTE: If you connect any essential signals for proper shutdown or cleanup of
-    // the script engine, make sure to add code to "reconnect" them to the
-    // disconnectNonEssentialSignals() method
-    connect(workerThread, &QThread::started, this, [this, name] {
-        setThreadName(name.toStdString());
-        run();
-    });
-    connect(this, &QObject::destroyed, workerThread, &QThread::quit);
-    connect(workerThread, &QThread::finished, workerThread, &QObject::deleteLater);
-
-    workerThread->start();
-}
-
-void ScriptEngine::executeOnScriptThread(std::function<void()> function, const Qt::ConnectionType& type ) {
-    if (QThread::currentThread() != thread()) {
-        QMetaObject::invokeMethod(this, "executeOnScriptThread", type, Q_ARG(std::function<void()>, function));
-        return;
-    }
-
-    function();
-}
-
-void ScriptEngine::waitTillDoneRunning(bool shutdown) {
-    // Engine should be stopped already, but be defensive
-    stop();
-    
-    auto workerThread = thread();
-    
-    if (workerThread == QThread::currentThread()) {
-        qCWarning(scriptengine) << "ScriptEngine::waitTillDoneRunning called, but the script is on the same thread:" << getFilename();
-        return;
-    }
-    
-    if (_isThreaded && workerThread) {
-        // We should never be waiting (blocking) on our own thread
-        assert(workerThread != QThread::currentThread());
-
-#if 0
-        // 26 Feb 2021 - Disabled this OSX-specific code because it causes OSX to crash on shutdown; without this code, OSX 
-        // doesn't crash on shutdown. Qt 5.12.3 and Qt 5.15.2.
-        //
-        // On mac, don't call QCoreApplication::processEvents() here. This is to prevent
-        // [NSApplication terminate:] from prematurely destroying the static destructors
-        // while we are waiting for the scripts to shutdown. We will pump the message
-        // queue later in the Application destructor.
-        if (workerThread->isRunning()) {
-            workerThread->quit();
-
-            if (isEvaluating()) {
-                qCWarning(scriptengine) << "Script Engine has been running too long, aborting:" << getFilename();
-                abortEvaluation();
-            } else {
-                auto context = currentContext();
-                if (context) {
-                    qCWarning(scriptengine) << "Script Engine has been running too long, throwing:" << getFilename();
-                    context->throwError("Timed out during shutdown");
-                }
-            }
-
-            // Wait for the scripting thread to stop running, as
-            // flooding it with aborts/exceptions will persist it longer
-            static const auto MAX_SCRIPT_QUITTING_TIME = 0.5 * MSECS_PER_SECOND;
-            if (!workerThread->wait(MAX_SCRIPT_QUITTING_TIME)) {
-                workerThread->terminate();
-            }
-        }
-#else
-        auto startedWaiting = usecTimestampNow();
-        while (workerThread->isRunning()) {
-            // If the final evaluation takes too long, then tell the script engine to stop running
-            auto elapsedUsecs = usecTimestampNow() - startedWaiting;
-            static const auto MAX_SCRIPT_EVALUATION_TIME = USECS_PER_SECOND;
-            if (elapsedUsecs > MAX_SCRIPT_EVALUATION_TIME) {
-                workerThread->quit();
-
-                if (isEvaluating()) {
-                    qCWarning(scriptengine) << "Script Engine has been running too long, aborting:" << getFilename();
-                    abortEvaluation();
-                } else {
-                    auto context = currentContext();
-                    if (context) {
-                        qCWarning(scriptengine) << "Script Engine has been running too long, throwing:" << getFilename();
-                        context->throwError("Timed out during shutdown");
-                    }
-                }
-
-                // Wait for the scripting thread to stop running, as
-                // flooding it with aborts/exceptions will persist it longer
-                static const auto MAX_SCRIPT_QUITTING_TIME = 0.5 * MSECS_PER_SECOND;
-                if (!workerThread->wait(MAX_SCRIPT_QUITTING_TIME)) {
-                    workerThread->terminate();
-                }
-            }
-
-            if (shutdown) {
-                // NOTE: This will be called on the main application thread (among other threads) from stopAllScripts.
-                //       The thread will need to continue to process events, because
-                //       the scripts will likely need to marshall messages across to the main thread, e.g.
-                //       if they access Settings or Menu in any of their shutdown code. So:
-                // Process events for this thread, allowing invokeMethod calls to pass between threads.
-                QCoreApplication::processEvents();
-            }
-
-            // Avoid a pure busy wait
-            QThread::yieldCurrentThread();
-        }
-#endif
-
-        scriptInfoMessage("Script Engine has stopped:" + getFilename());
-    }
-}
-
-QString ScriptEngine::getFilename() const {
-    QStringList fileNameParts = _fileNameString.split("/");
-    QString lastPart;
-    if (!fileNameParts.isEmpty()) {
-        lastPart = fileNameParts.last();
-    }
-    return lastPart;
-}
-
-bool ScriptEngine::hasValidScriptSuffix(const QString& scriptFileName) {
-    QFileInfo fileInfo(scriptFileName);
-    QString scriptSuffixToLower = fileInfo.completeSuffix().toLower();
-    return scriptSuffixToLower.contains(QString("js"), Qt::CaseInsensitive);
-}
-
-void ScriptEngine::loadURL(const QUrl& scriptURL, bool reload) {
-    if (_isRunning) {
-        return;
-    }
-
-    QUrl url = expandScriptUrl(scriptURL);
-    _fileNameString = url.toString();
-    _isReloading = reload;
-
-    // Check that script has a supported file extension
-    if (!hasValidScriptSuffix(_fileNameString)) {
-        scriptErrorMessage("File extension of file: " + _fileNameString + " is not a currently supported script type");
-        emit errorLoadingScript(_fileNameString);
-        return;
-    }
-
-    const auto maxRetries = 0; // for consistency with previous scriptCache->getScript() behavior
-    auto scriptCache = DependencyManager::get<ScriptCache>();
-    scriptCache->getScriptContents(url.toString(), [this](const QString& url, const QString& scriptContents, bool isURL, bool success, const QString&status) {
-        qCDebug(scriptengine) << "loadURL" << url << status << QThread::currentThread();
-        if (!success) {
-            scriptErrorMessage("ERROR Loading file (" + status + "):" + url);
-            emit errorLoadingScript(_fileNameString);
-            return;
-        }
-
-        _scriptContents = scriptContents;
-
-        emit scriptLoaded(url);
-    }, reload, maxRetries);
-}
-
-void ScriptEngine::scriptErrorMessage(const QString& message) {
-    qCCritical(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
-    emit errorMessage(message, getFilename());
-}
-
-void ScriptEngine::scriptWarningMessage(const QString& message) {
-    qCWarning(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
-    emit warningMessage(message, getFilename());
-}
-
-void ScriptEngine::scriptInfoMessage(const QString& message) {
-    qCInfo(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
-    emit infoMessage(message, getFilename());
-}
-
-void ScriptEngine::scriptPrintedMessage(const QString& message) {
-    qCDebug(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
-    emit printedMessage(message, getFilename());
-}
-
-void ScriptEngine::clearDebugLogWindow() {
-    emit clearDebugWindow();
-}
-
-// Even though we never pass AnimVariantMap directly to and from javascript, the queued invokeMethod of
-// callAnimationStateHandler requires that the type be registered.
-// These two are meaningful, if we ever do want to use them...
-static QScriptValue animVarMapToScriptValue(QScriptEngine* engine, const AnimVariantMap& parameters) {
-    QStringList unused;
-    return parameters.animVariantMapToScriptValue(engine, unused, false);
-}
-static void animVarMapFromScriptValue(const QScriptValue& value, AnimVariantMap& parameters) {
-    parameters.animVariantMapFromScriptValue(value);
-}
-// ... while these two are not. But none of the four are ever used.
-static QScriptValue resultHandlerToScriptValue(QScriptEngine* engine,
-                                               const AnimVariantResultHandler& resultHandler) {
-    qCCritical(scriptengine) << "Attempt to marshall result handler to javascript";
-    assert(false);
-    return QScriptValue();
-}
-static void resultHandlerFromScriptValue(const QScriptValue& value, AnimVariantResultHandler& resultHandler) {
-    qCCritical(scriptengine) << "Attempt to marshall result handler from javascript";
-    assert(false);
-}
-
-// Templated qScriptRegisterMetaType fails to compile with raw pointers
-using ScriptableResourceRawPtr = ScriptableResource*;
-
-static QScriptValue scriptableResourceToScriptValue(QScriptEngine* engine,
-                                                    const ScriptableResourceRawPtr& resource) {
-    if (!resource) {
-        return QScriptValue(); // probably shutting down
-    }
-
-    // The first script to encounter this resource will track its memory.
-    // In this way, it will be more likely to GC.
-    // This fails in the case that the resource is used across many scripts, but
-    // in that case it would be too difficult to tell which one should track the memory, and
-    // this serves the common case (use in a single script).
-    auto data = resource->getResource();
-    if (data && !resource->isInScript()) {
-        resource->setInScript(true);
-        QObject::connect(data.data(), SIGNAL(updateSize(qint64)), engine, SLOT(updateMemoryCost(qint64)));
-    }
-
-    auto object = engine->newQObject(
-        const_cast<ScriptableResourceRawPtr>(resource),
-        QScriptEngine::ScriptOwnership,
-        DEFAULT_QOBJECT_WRAP_OPTIONS);
-    return object;
-}
-
-static void scriptableResourceFromScriptValue(const QScriptValue& value, ScriptableResourceRawPtr& resource) {
-    resource = static_cast<ScriptableResourceRawPtr>(value.toQObject());
-}
-
-/*@jsdoc
- * The <code>Resource</code> API provides values that define the possible loading states of a resource.
- *
- * @namespace Resource
- *
- * @hifi-interface
- * @hifi-client-entity
- * @hifi-avatar
- * @hifi-server-entity
- * @hifi-assignment-client
- *
- * @property {Resource.State} State - The possible loading states of a resource. <em>Read-only.</em>
- */
-static QScriptValue createScriptableResourcePrototype(ScriptEnginePointer engine) {
-    auto prototype = engine->newObject();
-
-    // Expose enum State to JS/QML via properties
-    QObject* state = new QObject(engine.data());
-    state->setObjectName("ResourceState");
-    auto metaEnum = QMetaEnum::fromType<ScriptableResource::State>();
-    for (int i = 0; i < metaEnum.keyCount(); ++i) {
-        state->setProperty(metaEnum.key(i), metaEnum.value(i));
-    }
-
-    auto prototypeState = engine->newQObject(state, QScriptEngine::QtOwnership,
-       QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeSlots | QScriptEngine::ExcludeSuperClassMethods);
-    prototype.setProperty("State", prototypeState);
-
-    return prototype;
-}
-
-QScriptValue avatarDataToScriptValue(QScriptEngine* engine, ScriptAvatarData* const& in) {
-    return engine->newQObject(in, QScriptEngine::ScriptOwnership, DEFAULT_QOBJECT_WRAP_OPTIONS);
-}
-
-void avatarDataFromScriptValue(const QScriptValue& object, ScriptAvatarData*& out) {
-    // This is not implemented because there are no slots/properties that take an AvatarSharedPointer from a script
-    assert(false);
-    out = nullptr;
-}
-
-QScriptValue externalResourceBucketToScriptValue(QScriptEngine* engine, ExternalResource::Bucket const& in) {
-    return QScriptValue((int)in);
-}
-
-void externalResourceBucketFromScriptValue(const QScriptValue& object, ExternalResource::Bucket& out) {
-    out = static_cast<ExternalResource::Bucket>(object.toInt32());
-}
-
-void ScriptEngine::resetModuleCache(bool deleteScriptCache) {
-    if (QThread::currentThread() != thread()) {
-        executeOnScriptThread([=]() { resetModuleCache(deleteScriptCache); });
-        return;
-    }
-    auto jsRequire = globalObject().property("Script").property("require");
-    auto cache = jsRequire.property("cache");
-    auto cacheMeta = jsRequire.data();
-
-    if (deleteScriptCache) {
-        QScriptValueIterator it(cache);
-        while (it.hasNext()) {
-            it.next();
-            if (it.flags() & QScriptValue::SkipInEnumeration) {
-                continue;
-            }
-            qCDebug(scriptengine) << "resetModuleCache(true) -- staging " << it.name() << " for cache reset at next require";
-            cacheMeta.setProperty(it.name(), true);
-        }
-    }
-    cache = newObject();
-    if (!cacheMeta.isObject()) {
-        cacheMeta = newObject();
-        cacheMeta.setProperty("id", "Script.require.cacheMeta");
-        cacheMeta.setProperty("type", "cacheMeta");
-        jsRequire.setData(cacheMeta);
-    }
-    cache.setProperty("__created__", (double)QDateTime::currentMSecsSinceEpoch(), QScriptValue::SkipInEnumeration);
-#if DEBUG_JS_MODULES
-    cache.setProperty("__meta__", cacheMeta, READONLY_HIDDEN_PROP_FLAGS);
-#endif
-    jsRequire.setProperty("cache", cache, READONLY_PROP_FLAGS);
-}
-
-void ScriptEngine::init() {
-    if (_isInitialized) {
-        return; // only initialize once
-    }
-
-    _isInitialized = true;
-
-    auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
-    entityScriptingInterface->init();
-
-    // register various meta-types
-    registerMetaTypes(this);
-    registerMIDIMetaTypes(this);
-    registerEventTypes(this);
-    registerMenuItemProperties(this);
-    registerAnimationTypes(this);
-    registerAvatarTypes(this);
-    registerAudioMetaTypes(this);
-
-    qScriptRegisterMetaType(this, EntityPropertyFlagsToScriptValue, EntityPropertyFlagsFromScriptValue);
-    qScriptRegisterMetaType(this, EntityItemPropertiesToScriptValue, EntityItemPropertiesFromScriptValueHonorReadOnly);
-    qScriptRegisterMetaType(this, EntityPropertyInfoToScriptValue, EntityPropertyInfoFromScriptValue);
-    qScriptRegisterMetaType(this, EntityItemIDtoScriptValue, EntityItemIDfromScriptValue);
-    qScriptRegisterMetaType(this, RayToEntityIntersectionResultToScriptValue, RayToEntityIntersectionResultFromScriptValue);
-    qScriptRegisterMetaType(this, RayToAvatarIntersectionResultToScriptValue, RayToAvatarIntersectionResultFromScriptValue);
-    qScriptRegisterMetaType(this, AvatarEntityMapToScriptValue, AvatarEntityMapFromScriptValue);
-    qScriptRegisterSequenceMetaType<QVector<QUuid>>(this);
-    qScriptRegisterSequenceMetaType<QVector<EntityItemID>>(this);
-
-    qScriptRegisterSequenceMetaType<QVector<glm::vec2>>(this);
-    qScriptRegisterSequenceMetaType<QVector<glm::quat>>(this);
-    qScriptRegisterSequenceMetaType<QVector<QString>>(this);
-
-    QScriptValue xmlHttpRequestConstructorValue = newFunction(XMLHttpRequestClass::constructor);
-    globalObject().setProperty("XMLHttpRequest", xmlHttpRequestConstructorValue);
-
-    QScriptValue webSocketConstructorValue = newFunction(WebSocketClass::constructor);
-    globalObject().setProperty("WebSocket", webSocketConstructorValue);
-
-    /*@jsdoc
-     * Prints a message to the program log and emits {@link Script.printedMessage}.
-     * The message logged is the message values separated by spaces.
-     * <p>Alternatively, you can use {@link Script.print} or one of the {@link console} API methods.</p>
-     * @function print
-     * @param {...*} [message] - The message values to print.
-     */
-    globalObject().setProperty("print", newFunction(debugPrint));
-
-    QScriptValue audioEffectOptionsConstructorValue = newFunction(AudioEffectOptions::constructor);
-    globalObject().setProperty("AudioEffectOptions", audioEffectOptionsConstructorValue);
-
-    qScriptRegisterMetaType(this, injectorToScriptValue, injectorFromScriptValue);
-    qScriptRegisterMetaType(this, inputControllerToScriptValue, inputControllerFromScriptValue);
-    qScriptRegisterMetaType(this, avatarDataToScriptValue, avatarDataFromScriptValue);
-    qScriptRegisterMetaType(this, animationDetailsToScriptValue, animationDetailsFromScriptValue);
-    qScriptRegisterMetaType(this, webSocketToScriptValue, webSocketFromScriptValue);
-    qScriptRegisterMetaType(this, qWSCloseCodeToScriptValue, qWSCloseCodeFromScriptValue);
-    qScriptRegisterMetaType(this, wscReadyStateToScriptValue, wscReadyStateFromScriptValue);
-
-    // NOTE: You do not want to end up creating new instances of singletons here. They will be on the ScriptEngine thread
-    // and are likely to be unusable if we "reset" the ScriptEngine by creating a new one (on a whole new thread).
-
-    registerGlobalObject("Script", this);
-
-    {
-        // set up Script.require.resolve and Script.require.cache
-        auto Script = globalObject().property("Script");
-        auto require = Script.property("require");
-        auto resolve = Script.property("_requireResolve");
-        require.setProperty("resolve", resolve, READONLY_PROP_FLAGS);
-        resetModuleCache();
-    }
-
-    qScriptRegisterMetaType(this, externalResourceBucketToScriptValue, externalResourceBucketFromScriptValue);
-    registerEnum("Script.ExternalPaths", QMetaEnum::fromType<ExternalResource::Bucket>());
-
-    registerGlobalObject("Audio", DependencyManager::get<AudioScriptingInterface>().data());
-
-    registerGlobalObject("Midi", DependencyManager::get<Midi>().data());
-
-    registerGlobalObject("Entities", entityScriptingInterface.data());
-    registerFunction("Entities", "getMultipleEntityProperties", EntityScriptingInterface::getMultipleEntityProperties);
-    registerGlobalObject("Quat", &_quatLibrary);
-    registerGlobalObject("Vec3", &_vec3Library);
-    registerGlobalObject("Mat4", &_mat4Library);
-    registerGlobalObject("Uuid", &_uuidLibrary);
-    registerGlobalObject("Messages", DependencyManager::get<MessagesClient>().data());
-    registerGlobalObject("File", new FileScriptingInterface(this));
-    registerGlobalObject("console", &_consoleScriptingInterface);
-    registerFunction("console", "info", ConsoleScriptingInterface::info, currentContext()->argumentCount());
-    registerFunction("console", "log", ConsoleScriptingInterface::log, currentContext()->argumentCount());
-    registerFunction("console", "debug", ConsoleScriptingInterface::debug, currentContext()->argumentCount());
-    registerFunction("console", "warn", ConsoleScriptingInterface::warn, currentContext()->argumentCount());
-    registerFunction("console", "error", ConsoleScriptingInterface::error, currentContext()->argumentCount());
-    registerFunction("console", "exception", ConsoleScriptingInterface::exception, currentContext()->argumentCount());
-    registerFunction("console", "assert", ConsoleScriptingInterface::assertion, currentContext()->argumentCount());
-    registerFunction("console", "group", ConsoleScriptingInterface::group, 1);
-    registerFunction("console", "groupCollapsed", ConsoleScriptingInterface::groupCollapsed, 1);
-    registerFunction("console", "groupEnd", ConsoleScriptingInterface::groupEnd, 0);
-
-    qScriptRegisterMetaType(this, animVarMapToScriptValue, animVarMapFromScriptValue);
-    qScriptRegisterMetaType(this, resultHandlerToScriptValue, resultHandlerFromScriptValue);
-
-    // Scriptable cache access
-    auto resourcePrototype = createScriptableResourcePrototype(qSharedPointerCast<ScriptEngine>(sharedFromThis()));
-    globalObject().setProperty("Resource", resourcePrototype);
-    setDefaultPrototype(qMetaTypeId<ScriptableResource*>(), resourcePrototype);
-    qScriptRegisterMetaType(this, scriptableResourceToScriptValue, scriptableResourceFromScriptValue);
-
-    // constants
-    globalObject().setProperty("TREE_SCALE", newVariant(QVariant(TREE_SCALE)));
-
-    registerGlobalObject("Assets", _assetScriptingInterface);
-    registerGlobalObject("Resources", DependencyManager::get<ResourceScriptingInterface>().data());
-
-    registerGlobalObject("DebugDraw", &DebugDraw::getInstance());
-
-    registerGlobalObject("Model", new ModelScriptingInterface(this));
-    qScriptRegisterMetaType(this, meshToScriptValue, meshFromScriptValue);
-    qScriptRegisterMetaType(this, meshesToScriptValue, meshesFromScriptValue);
-
-    registerGlobalObject("UserActivityLogger", DependencyManager::get<UserActivityLoggerScriptingInterface>().data());
-
-#if DEV_BUILD || PR_BUILD
-    registerGlobalObject("StackTest", new StackTestScriptingInterface(this));
-#endif
-
-    globalObject().setProperty("KALILA", "isWaifu");
-    globalObject().setProperty("Kute", newFunction([](QScriptContext* context, QScriptEngine* engine) -> QScriptValue {
-      return context->argument(0).toString().toLower() == "kalila" ? true : false;
-    }));
-}
+#include "ScriptValue.h"
+#include "qtscript/ScriptEngineQtScript.h"
 
-void ScriptEngine::registerEnum(const QString& enumName, QMetaEnum newEnum) {
-    if (!newEnum.isValid()) {
-        qCCritical(scriptengine) << "registerEnum called on invalid enum with name " << enumName;
-        return;
-    }
-
-    for (int i = 0; i < newEnum.keyCount(); i++) {
-        const char* keyName = newEnum.key(i);
-        QString fullName = enumName + "." + keyName;
-        registerValue(fullName, newEnum.keyToValue(keyName));
-    }
+ScriptEnginePointer newScriptEngine(ScriptManager* manager) {
+    return std::make_shared<ScriptEngineQtScript>(manager);
 }
 
-void ScriptEngine::registerValue(const QString& valueName, QScriptValue value) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::registerValue() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
-#endif
-        QMetaObject::invokeMethod(this, "registerValue",
-                                  Q_ARG(const QString&, valueName),
-                                  Q_ARG(QScriptValue, value));
-        return;
+ScriptValue makeScopedHandlerObject(const ScriptValue& scopeOrCallback, const ScriptValue& methodOrName) {
+    auto engine = scopeOrCallback.engine();
+    if (!engine) {
+        return scopeOrCallback;
     }
-
-    QStringList pathToValue = valueName.split(".");
-    int partsToGo = pathToValue.length();
-    QScriptValue partObject = globalObject();
-
-    for (const auto& pathPart : pathToValue) {
-        partsToGo--;
-        if (!partObject.property(pathPart).isValid()) {
-            if (partsToGo > 0) {
-                //QObject *object = new QObject;
-                QScriptValue partValue = newArray(); //newQObject(object, QScriptEngine::ScriptOwnership);
-                partObject.setProperty(pathPart, partValue);
-            } else {
-                partObject.setProperty(pathPart, value);
+    ScriptValue scope;
+    ScriptValue callback = scopeOrCallback;
+    if (scopeOrCallback.isObject()) {
+        if (methodOrName.isString()) {
+            scope = scopeOrCallback;
+            callback = scope.property(methodOrName.toString());
+        } else if (methodOrName.isFunction()) {
+            scope = scopeOrCallback;
+            callback = methodOrName;
+        } else if (!methodOrName.isValid()) {
+            // instantiate from an existing scoped handler object
+            if (scopeOrCallback.property("callback").isFunction()) {
+                scope = scopeOrCallback.property("scope");
+                callback = scopeOrCallback.property("callback");
             }
         }
-        partObject = partObject.property(pathPart);
-    }
-}
-
-void ScriptEngine::registerGlobalObject(const QString& name, QObject* object) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::registerGlobalObject() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  name:" << name;
-#endif
-        QMetaObject::invokeMethod(this, "registerGlobalObject",
-                                  Q_ARG(const QString&, name),
-                                  Q_ARG(QObject*, object));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::registerGlobalObject() called on thread [" << QThread::currentThread() << "] name:" << name;
-#endif
-
-    if (!globalObject().property(name).isValid()) {
-        if (object) {
-            QScriptValue value = newQObject(object, QScriptEngine::QtOwnership, DEFAULT_QOBJECT_WRAP_OPTIONS);
-            globalObject().setProperty(name, value);
-        } else {
-            globalObject().setProperty(name, QScriptValue());
-        }
-    }
-}
-
-void ScriptEngine::registerFunction(const QString& name, QScriptEngine::FunctionSignature functionSignature, int numArguments) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] name:" << name;
-#endif
-        QMetaObject::invokeMethod(this, "registerFunction",
-                                  Q_ARG(const QString&, name),
-                                  Q_ARG(QScriptEngine::FunctionSignature, functionSignature),
-                                  Q_ARG(int, numArguments));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::registerFunction() called on thread [" << QThread::currentThread() << "] name:" << name;
-#endif
-
-    QScriptValue scriptFun = newFunction(functionSignature, numArguments);
-    globalObject().setProperty(name, scriptFun);
-}
-
-void ScriptEngine::registerFunction(const QString& parent, const QString& name, QScriptEngine::FunctionSignature functionSignature, int numArguments) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] parent:" << parent << "name:" << name;
-#endif
-        QMetaObject::invokeMethod(this, "registerFunction",
-                                  Q_ARG(const QString&, name),
-                                  Q_ARG(QScriptEngine::FunctionSignature, functionSignature),
-                                  Q_ARG(int, numArguments));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::registerFunction() called on thread [" << QThread::currentThread() << "] parent:" << parent << "name:" << name;
-#endif
-
-    QScriptValue object = globalObject().property(parent);
-    if (object.isValid()) {
-        QScriptValue scriptFun = newFunction(functionSignature, numArguments);
-        object.setProperty(name, scriptFun);
-    }
-}
-
-void ScriptEngine::registerGetterSetter(const QString& name, QScriptEngine::FunctionSignature getter,
-                                        QScriptEngine::FunctionSignature setter, const QString& parent) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::registerGetterSetter() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
-            " name:" << name << "parent:" << parent;
-#endif
-        QMetaObject::invokeMethod(this, "registerGetterSetter",
-                                  Q_ARG(const QString&, name),
-                                  Q_ARG(QScriptEngine::FunctionSignature, getter),
-                                  Q_ARG(QScriptEngine::FunctionSignature, setter),
-                                  Q_ARG(const QString&, parent));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::registerGetterSetter() called on thread [" << QThread::currentThread() << "] name:" << name << "parent:" << parent;
-#endif
-
-    QScriptValue setterFunction = newFunction(setter, 1);
-    QScriptValue getterFunction = newFunction(getter);
-
-    if (!parent.isNull() && !parent.isEmpty()) {
-        QScriptValue object = globalObject().property(parent);
-        if (object.isValid()) {
-            object.setProperty(name, setterFunction, QScriptValue::PropertySetter);
-            object.setProperty(name, getterFunction, QScriptValue::PropertyGetter);
-        }
-    } else {
-        globalObject().setProperty(name, setterFunction, QScriptValue::PropertySetter);
-        globalObject().setProperty(name, getterFunction, QScriptValue::PropertyGetter);
-    }
-}
-
-// Unregister the handlers for this eventName and entityID.
-void ScriptEngine::removeEventHandler(const EntityItemID& entityID, const QString& eventName, QScriptValue handler) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::removeEventHandler() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
-            "entityID:" << entityID << " eventName:" << eventName;
-#endif
-        QMetaObject::invokeMethod(this, "removeEventHandler",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, eventName),
-                                  Q_ARG(QScriptValue, handler));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::removeEventHandler() called on thread [" << QThread::currentThread() << "] entityID:" << entityID << " eventName : " << eventName;
-#endif
-
-    if (!_registeredHandlers.contains(entityID)) {
-        return;
-    }
-    RegisteredEventHandlers& handlersOnEntity = _registeredHandlers[entityID];
-    CallbackList& handlersForEvent = handlersOnEntity[eventName];
-    // QScriptValue does not have operator==(), so we can't use QList::removeOne and friends. So iterate.
-    for (int i = 0; i < handlersForEvent.count(); ++i) {
-        if (handlersForEvent[i].function.equals(handler)) {
-            handlersForEvent.removeAt(i);
-            return; // Design choice: since comparison is relatively expensive, just remove the first matching handler.
-        }
-    }
-}
-// Register the handler.
-void ScriptEngine::addEventHandler(const EntityItemID& entityID, const QString& eventName, QScriptValue handler) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::addEventHandler() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
-        "entityID:" << entityID << " eventName:" << eventName;
-#endif
-
-        QMetaObject::invokeMethod(this, "addEventHandler",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, eventName),
-                                  Q_ARG(QScriptValue, handler));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::addEventHandler() called on thread [" << QThread::currentThread() << "] entityID:" << entityID << " eventName : " << eventName;
-#endif
-
-    if (_registeredHandlers.count() == 0) { // First time any per-entity handler has been added in this script...
-        // Connect up ALL the handlers to the global entities object's signals.
-        // (We could go signal by signal, or even handler by handler, but I don't think the efficiency is worth the complexity.)
-        auto entities = DependencyManager::get<EntityScriptingInterface>();
-        // Bug? These handlers are deleted when entityID is deleted, which is nice.
-        // But if they are created by an entity script on a different entity, should they also be deleted when the entity script unloads?
-        // E.g., suppose a bow has an entity script that causes arrows to be created with a potential lifetime greater than the bow,
-        // and that the entity script adds (e.g., collision) handlers to the arrows. Should those handlers fire if the bow is unloaded?
-        // Also, what about when the entity script is REloaded?
-        // For now, we are leaving them around. Changing that would require some non-trivial digging around to find the
-        // handlers that were added while a given currentEntityIdentifier was in place. I don't think this is dangerous. Just perhaps unexpected. -HRS
-        connect(entities.data(), &EntityScriptingInterface::deletingEntity, this, [this](const EntityItemID& entityID) {
-            _registeredHandlers.remove(entityID);
-        });
-
-        // Two common cases of event handler, differing only in argument signature.
-
-        /*@jsdoc
-         * Called when an entity event occurs on an entity as registered with {@link Script.addEventHandler}.
-         * @callback Script~entityEventCallback
-         * @param {Uuid} entityID - The ID of the entity the event has occured on.
-         */
-        using SingleEntityHandler = std::function<void(const EntityItemID&)>;
-        auto makeSingleEntityHandler = [this](QString eventName) -> SingleEntityHandler {
-            return [this, eventName](const EntityItemID& entityItemID) {
-                forwardHandlerCall(entityItemID, eventName, { entityItemID.toScriptValue(this) });
-            };
-        };
-
-        /*@jsdoc
-         * Called when a pointer event occurs on an entity as registered with {@link Script.addEventHandler}.
-         * @callback Script~pointerEventCallback
-         * @param {Uuid} entityID - The ID of the entity the event has occurred on.
-         * @param {PointerEvent} pointerEvent - Details of the event.
-         */
-        using PointerHandler = std::function<void(const EntityItemID&, const PointerEvent&)>;
-        auto makePointerHandler = [this](QString eventName) -> PointerHandler {
-            return [this, eventName](const EntityItemID& entityItemID, const PointerEvent& event) {
-                if (!EntityTree::areEntityClicksCaptured()) {
-                    forwardHandlerCall(entityItemID, eventName, { entityItemID.toScriptValue(this), event.toScriptValue(this) });
-                }
-            };
-        };
-
-        /*@jsdoc
-         * Called when a collision event occurs on an entity as registered with {@link Script.addEventHandler}.
-         * @callback Script~collisionEventCallback
-         * @param {Uuid} entityA - The ID of one entity in the collision.
-         * @param {Uuid} entityB - The ID of the other entity in the collision.
-         * @param {Collision} collisionEvent - Details of the collision.
-         */
-        using CollisionHandler = std::function<void(const EntityItemID&, const EntityItemID&, const Collision&)>;
-        auto makeCollisionHandler = [this](QString eventName) -> CollisionHandler {
-            return [this, eventName](const EntityItemID& idA, const EntityItemID& idB, const Collision& collision) {
-                forwardHandlerCall(idA, eventName, { idA.toScriptValue(this), idB.toScriptValue(this),
-                    collisionToScriptValue(this, collision) });
-            };
-        };
-
-        /*@jsdoc
-         * <p>The name of an entity event. When the entity event occurs, any function that has been registered for that event 
-         * via {@link Script.addEventHandler} is called with parameters per the entity event.</p>
-         * <table>
-         *   <thead>
-         *     <tr><th>Event Name</th><th>Callback Type</th><th>Entity Event</th></tr>
-         *   </thead>
-         *   <tbody>
-         *     <tr><td><code>"enterEntity"</code></td><td>{@link Script~entityEventCallback|entityEventCallback}</td>
-         *       <td>{@link Entities.enterEntity}</td></tr>
-         *     <tr><td><code>"leaveEntity"</code></td><td>{@link Script~entityEventCallback|entityEventCallback}</td>
-         *       <td>{@link Entities.leaveEntity}</td></tr>
-         *     <tr><td><code>"mousePressOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.mousePressOnEntity}</td></tr>
-         *     <tr><td><code>"mouseMoveOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.mouseMoveOnEntity}</td></tr>
-         *     <tr><td><code>"mouseReleaseOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.mouseReleaseOnEntity}</td></tr>
-         *     <tr><td><code>"clickDownOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.clickDownOnEntity}</td></tr>
-         *     <tr><td><code>"holdingClickOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.holdingClickOnEntity}</td></tr>
-         *     <tr><td><code>"clickReleaseOnEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.clickReleaseOnEntity}</td></tr>
-         *     <tr><td><code>"hoverEnterEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.hoverEnterEntity}</td></tr>
-         *     <tr><td><code>"hoverOverEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.hoverOverEntity}</td></tr>
-         *     <tr><td><code>"hoverLeaveEntity"</code></td><td>{@link Script~pointerEventCallback|pointerEventCallback}</td>
-         *       <td>{@link Entities.hoverLeaveEntity}</td></tr>
-         *     <tr><td><code>"collisionWithEntity"</code><td>{@link Script~collisionEventCallback|collisionEventCallback}</td>
-         *       </td><td>{@link Entities.collisionWithEntity}</td></tr>
-         *   </tbody>
-         * </table>
-         * @typedef {string} Script.EntityEvent
-         */
-        connect(entities.data(), &EntityScriptingInterface::enterEntity, this, makeSingleEntityHandler("enterEntity"));
-        connect(entities.data(), &EntityScriptingInterface::leaveEntity, this, makeSingleEntityHandler("leaveEntity"));
-
-        connect(entities.data(), &EntityScriptingInterface::mousePressOnEntity, this, makePointerHandler("mousePressOnEntity"));
-        connect(entities.data(), &EntityScriptingInterface::mouseMoveOnEntity, this, makePointerHandler("mouseMoveOnEntity"));
-        connect(entities.data(), &EntityScriptingInterface::mouseReleaseOnEntity, this, makePointerHandler("mouseReleaseOnEntity"));
-
-        connect(entities.data(), &EntityScriptingInterface::clickDownOnEntity, this, makePointerHandler("clickDownOnEntity"));
-        connect(entities.data(), &EntityScriptingInterface::holdingClickOnEntity, this, makePointerHandler("holdingClickOnEntity"));
-        connect(entities.data(), &EntityScriptingInterface::clickReleaseOnEntity, this, makePointerHandler("clickReleaseOnEntity"));
-
-        connect(entities.data(), &EntityScriptingInterface::hoverEnterEntity, this, makePointerHandler("hoverEnterEntity"));
-        connect(entities.data(), &EntityScriptingInterface::hoverOverEntity, this, makePointerHandler("hoverOverEntity"));
-        connect(entities.data(), &EntityScriptingInterface::hoverLeaveEntity, this, makePointerHandler("hoverLeaveEntity"));
-
-        connect(entities.data(), &EntityScriptingInterface::collisionWithEntity, this, makeCollisionHandler("collisionWithEntity"));
     }
-    if (!_registeredHandlers.contains(entityID)) {
-        _registeredHandlers[entityID] = RegisteredEventHandlers();
-    }
-    CallbackList& handlersForEvent = _registeredHandlers[entityID][eventName];
-    CallbackData handlerData = { handler, currentEntityIdentifier, currentSandboxURL };
-    handlersForEvent << handlerData; // Note that the same handler can be added many times. See removeEntityEventHandler().
-}
-
-// this is not redundant -- the version in BaseScriptEngine is specifically not Q_INVOKABLE
-QScriptValue ScriptEngine::evaluateInClosure(const QScriptValue& closure, const QScriptProgram& program) {
-    return BaseScriptEngine::evaluateInClosure(closure, program);
+    auto handler = engine->newObject();
+    handler.setProperty("scope", scope);
+    handler.setProperty("callback", callback);
+    return handler;
 }
 
-QScriptValue ScriptEngine::evaluate(const QString& sourceCode, const QString& fileName, int lineNumber) {
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        return QScriptValue(); // bail early
-    }
-
-    if (QThread::currentThread() != thread()) {
-        QScriptValue result;
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::evaluate() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
-            "sourceCode:" << sourceCode << " fileName:" << fileName << "lineNumber:" << lineNumber;
-#endif
-        BLOCKING_INVOKE_METHOD(this, "evaluate",
-                                  Q_RETURN_ARG(QScriptValue, result),
-                                  Q_ARG(const QString&, sourceCode),
-                                  Q_ARG(const QString&, fileName),
-                                  Q_ARG(int, lineNumber));
-        return result;
-    }
-
-    // Check syntax
-    auto syntaxError = lintScript(sourceCode, fileName);
-    if (syntaxError.isError()) {
-        if (!isEvaluating()) {
-            syntaxError.setProperty("detail", "evaluate");
-        }
-        raiseException(syntaxError);
-        maybeEmitUncaughtException("lint");
-        return syntaxError;
-    }
-    QScriptProgram program { sourceCode, fileName, lineNumber };
-    if (program.isNull()) {
-        // can this happen?
-        auto err = makeError("could not create QScriptProgram for " + fileName);
-        raiseException(err);
-        maybeEmitUncaughtException("compile");
-        return err;
-    }
-
-    QScriptValue result;
-    {
-        result = BaseScriptEngine::evaluate(program);
-        maybeEmitUncaughtException("evaluate");
-    }
-    return result;
+ScriptValue callScopedHandlerObject(const ScriptValue& handler, const ScriptValue& err, const ScriptValue& result) {
+    return handler.property("callback").call(handler.property("scope"), ScriptValueList({ err, result }));
 }
 
-void ScriptEngine::run() {
-    if (QThread::currentThread() != qApp->thread() && _context == Context::CLIENT_SCRIPT) {
-        // Flag that we're allowed to access local HTML files on UI created from C++ calls on this thread
-        // (because we're a client script)
-        hifi::scripting::setLocalAccessSafeThread(true);
-    }
-
-    auto filenameParts = _fileNameString.split("/");
-    auto name = filenameParts.size() > 0 ? filenameParts[filenameParts.size() - 1] : "unknown";
-    PROFILE_SET_THREAD_NAME("Script: " + name);
-
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        return; // bail early - avoid setting state in init(), as evaluate() will bail too
-    }
-
-    scriptInfoMessage("Script Engine starting:" + getFilename());
-
-    if (!_isInitialized) {
-        init();
-    }
-
-    _isRunning = true;
-    emit runningStateChanged();
-
-    {
-        PROFILE_RANGE(script, _fileNameString);
-        evaluate(_scriptContents, _fileNameString);
-        maybeEmitUncaughtException(__FUNCTION__);
-    }
-#ifdef _WIN32
-    // VS13 does not sleep_until unless it uses the system_clock, see:
-    // https://www.reddit.com/r/cpp_questions/comments/3o71ic/sleep_until_not_working_with_a_time_pointsteady/
-    using clock = std::chrono::system_clock;
-#else
-    using clock = std::chrono::high_resolution_clock;
-#endif
-
-    clock::time_point startTime = clock::now();
-    int thisFrame = 0;
-
-    auto nodeList = DependencyManager::get<NodeList>();
-    auto entityScriptingInterface = DependencyManager::get<EntityScriptingInterface>();
-
-    _lastUpdate = usecTimestampNow();
-
-    std::chrono::microseconds totalUpdates(0);
-
-    // TODO: Integrate this with signals/slots instead of reimplementing throttling for ScriptEngine
-    while (!_isFinished) {
-        auto beforeSleep = clock::now();
-
-        // Throttle to SCRIPT_FPS
-        // We'd like to try to keep the script at a solid SCRIPT_FPS update rate. And so we will
-        // calculate a sleepUntil to be the time from our start time until the original target
-        // sleepUntil for this frame. This approach will allow us to "catch up" in the event
-        // that some of our script udpates/frames take a little bit longer than the target average
-        // to execute.
-        // NOTE: if we go to variable SCRIPT_FPS, then we will need to reconsider this approach
-        const std::chrono::microseconds TARGET_SCRIPT_FRAME_DURATION(USECS_PER_SECOND / SCRIPT_FPS + 1);
-        clock::time_point targetSleepUntil(startTime + (thisFrame++ * TARGET_SCRIPT_FRAME_DURATION));
-
-        // However, if our sleepUntil is not at least our average update and timer execution time
-        // into the future it means our script is taking too long in its updates, and we want to
-        // punish the script a little bit. So we will force the sleepUntil to be at least our
-        // averageUpdate + averageTimerPerFrame time into the future.
-        auto averageUpdate = totalUpdates / thisFrame;
-        auto averageTimerPerFrame = _totalTimerExecution / thisFrame;
-        auto averageTimerAndUpdate = averageUpdate + averageTimerPerFrame;
-        auto sleepUntil = std::max(targetSleepUntil, beforeSleep + averageTimerAndUpdate);
-
-        // We don't want to actually sleep for too long, because it causes our scripts to hang
-        // on shutdown and stop... so we want to loop and sleep until we've spent our time in
-        // purgatory, constantly checking to see if our script was asked to end
-        bool processedEvents = false;
-        if (!_isFinished) {
-            PROFILE_RANGE(script, "processEvents-sleep");
-            std::chrono::milliseconds sleepFor =
-                std::chrono::duration_cast<std::chrono::milliseconds>(sleepUntil - clock::now());
-            if (sleepFor > std::chrono::milliseconds(0)) {
-                QEventLoop loop;
-                QTimer timer;
-                timer.setSingleShot(true);
-                connect(&timer, SIGNAL(timeout()), &loop, SLOT(quit()));
-                timer.start(sleepFor.count());
-                loop.exec();
-            } else {
-                QCoreApplication::processEvents();
-            }
-            processedEvents = true;
-        }
-
-        PROFILE_RANGE(script, "ScriptMainLoop");
-
-#ifdef SCRIPT_DELAY_DEBUG
-        {
-            auto actuallySleptUntil = clock::now();
-            uint64_t seconds = std::chrono::duration_cast<std::chrono::seconds>(actuallySleptUntil - startTime).count();
-            if (seconds > 0) { // avoid division by zero and time travel
-                uint64_t fps = thisFrame / seconds;
-                // Overreporting artificially reduces the reported rate
-                if (thisFrame % SCRIPT_FPS == 0) {
-                    qCDebug(scriptengine) <<
-                        "Frame:" << thisFrame <<
-                        "Slept (us):" << std::chrono::duration_cast<std::chrono::microseconds>(actuallySleptUntil - beforeSleep).count() <<
-                        "Avg Updates (us):" << averageUpdate.count() <<
-                        "FPS:" << fps;
-                }
-            }
-        }
-#endif
-        if (_isFinished) {
-            break;
-        }
-
-        // Only call this if we didn't processEvents as part of waiting for next frame
-        if (!processedEvents) {
-            PROFILE_RANGE(script, "processEvents");
-            QCoreApplication::processEvents();
-        }
-
-        if (_isFinished) {
-            break;
-        }
-
-        if (!_isFinished && entityScriptingInterface->getEntityPacketSender()->serversExist()) {
-            // release the queue of edit entity messages.
-            entityScriptingInterface->getEntityPacketSender()->releaseQueuedMessages();
-
-            // since we're in non-threaded mode, call process so that the packets are sent
-            if (!entityScriptingInterface->getEntityPacketSender()->isThreaded()) {
-                entityScriptingInterface->getEntityPacketSender()->process();
-            }
-        }
-
-        qint64 now = usecTimestampNow();
-
-        // we check for 'now' in the past in case people set their clock back
-        if (_emitScriptUpdates() && _lastUpdate < now) {
-            float deltaTime = (float) (now - _lastUpdate) / (float) USECS_PER_SECOND;
-            if (!_isFinished) {
-                auto preUpdate = clock::now();
-                {
-                    PROFILE_RANGE(script, "ScriptUpdate");
-                    emit update(deltaTime);
-                }
-                auto postUpdate = clock::now();
-                auto elapsed = (postUpdate - preUpdate);
-                totalUpdates += std::chrono::duration_cast<std::chrono::microseconds>(elapsed);
-            }
-        }
-        _lastUpdate = now;
-
-        // only clear exceptions if we are not in the middle of evaluating
-        if (!isEvaluating() && hasUncaughtException()) {
-            qCWarning(scriptengine) << __FUNCTION__ << "---------- UNCAUGHT EXCEPTION --------";
-            qCWarning(scriptengine) << "runInThread" << uncaughtException().toString();
-            emit unhandledException(cloneUncaughtException(__FUNCTION__));
-            clearExceptions();
-        }
-    }
-    scriptInfoMessage("Script Engine stopping:" + getFilename());
-
-    stopAllTimers(); // make sure all our timers are stopped if the script is ending
-    emit scriptEnding();
-
-    if (entityScriptingInterface->getEntityPacketSender()->serversExist()) {
-        // release the queue of edit entity messages.
-        entityScriptingInterface->getEntityPacketSender()->releaseQueuedMessages();
-
-        // since we're in non-threaded mode, call process so that the packets are sent
-        if (!entityScriptingInterface->getEntityPacketSender()->isThreaded()) {
-            // wait here till the edit packet sender is completely done sending
-            while (entityScriptingInterface->getEntityPacketSender()->hasPacketsToSend()) {
-                entityScriptingInterface->getEntityPacketSender()->process();
-                QCoreApplication::processEvents();
-            }
-        } else {
-            // FIXME - do we need to have a similar "wait here" loop for non-threaded packet senders?
-        }
-    }
-
-    emit finished(_fileNameString, qSharedPointerCast<ScriptEngine>(sharedFromThis()));
-
-    // Don't leave our local-file-access flag laying around, reset it to false when the scriptengine 
-    // thread is finished
-    hifi::scripting::setLocalAccessSafeThread(false);
-    _isRunning = false;
-    emit runningStateChanged();
-    emit doneRunning();
-}
-
-// NOTE: This is private because it must be called on the same thread that created the timers, which is why
-// we want to only call it in our own run "shutdown" processing.
-void ScriptEngine::stopAllTimers() {
-    QMutableHashIterator<QTimer*, CallbackData> i(_timerFunctionMap);
-    int j {0};
-    while (i.hasNext()) {
-        i.next();
-        QTimer* timer = i.key();
-        qCDebug(scriptengine) << getFilename() << "stopAllTimers[" << j++ << "]";
-        stopTimer(timer);
-    }
-}
-
-void ScriptEngine::stopAllTimersForEntityScript(const EntityItemID& entityID) {
-     // We could maintain a separate map of entityID => QTimer, but someone will have to prove to me that it's worth the complexity. -HRS
-    QVector<QTimer*> toDelete;
-    QMutableHashIterator<QTimer*, CallbackData> i(_timerFunctionMap);
-    while (i.hasNext()) {
-        i.next();
-        if (i.value().definingEntityIdentifier != entityID) {
-            continue;
-        }
-        QTimer* timer = i.key();
-        toDelete << timer; // don't delete while we're iterating. save it.
-    }
-    for (auto timer:toDelete) { // now reap 'em
-        stopTimer(timer);
-    }
-
-}
-
-void ScriptEngine::stop(bool marshal) {
-    _isStopping = true; // this can be done on any thread
-
-    if (marshal) {
-        QMetaObject::invokeMethod(this, "stop");
-        return;
-    }
-    if (!_isFinished) {
-        _isFinished = true;
-        emit runningStateChanged();
-    }
-}
-
-// Other threads can invoke this through invokeMethod, which causes the callback to be asynchronously executed in this script's thread.
-void ScriptEngine::callAnimationStateHandler(QScriptValue callback, AnimVariantMap parameters, QStringList names, bool useNames, AnimVariantResultHandler resultHandler) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::callAnimationStateHandler() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  name:" << name;
-#endif
-        QMetaObject::invokeMethod(this, "callAnimationStateHandler",
-                                  Q_ARG(QScriptValue, callback),
-                                  Q_ARG(AnimVariantMap, parameters),
-                                  Q_ARG(QStringList, names),
-                                  Q_ARG(bool, useNames),
-                                  Q_ARG(AnimVariantResultHandler, resultHandler));
-        return;
-    }
-    QScriptValue javascriptParameters = parameters.animVariantMapToScriptValue(this, names, useNames);
-    QScriptValueList callingArguments;
-    callingArguments << javascriptParameters;
-    assert(currentEntityIdentifier.isInvalidID()); // No animation state handlers from entity scripts.
-    QScriptValue result = callback.call(QScriptValue(), callingArguments);
-
-    // validate result from callback function.
-    if (result.isValid() && result.isObject()) {
-        resultHandler(result);
-    } else {
-        qCWarning(scriptengine) << "ScriptEngine::callAnimationStateHandler invalid return argument from callback, expected an object";
-    }
-}
-
-void ScriptEngine::updateMemoryCost(const qint64& deltaSize) {
-    if (deltaSize > 0) {
-        // We've patched qt to fix https://highfidelity.atlassian.net/browse/BUGZ-46 on mac and windows only.
-#if defined(Q_OS_WIN) || defined(Q_OS_MAC)
-        reportAdditionalMemoryCost(deltaSize);
-#endif
-    }
-}
-
-void ScriptEngine::timerFired() {
-    {
-        QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-        if (!scriptEngines || scriptEngines->isStopped()) {
-            scriptWarningMessage("Script.timerFired() while shutting down is ignored... parent script:" + getFilename());
-            return; // bail early
-        }
-    }
-
-    QTimer* callingTimer = reinterpret_cast<QTimer*>(sender());
-    CallbackData timerData = _timerFunctionMap.value(callingTimer);
-
-    if (!callingTimer->isActive()) {
-        // this timer is done, we can kill it
-        _timerFunctionMap.remove(callingTimer);
-        delete callingTimer;
-    }
-
-    // call the associated JS function, if it exists
-    if (timerData.function.isValid()) {
-        PROFILE_RANGE(script, __FUNCTION__);
-        auto preTimer = p_high_resolution_clock::now();
-        callWithEnvironment(timerData.definingEntityIdentifier, timerData.definingSandboxURL, timerData.function, timerData.function, QScriptValueList());
-        auto postTimer = p_high_resolution_clock::now();
-        auto elapsed = (postTimer - preTimer);
-        _totalTimerExecution += std::chrono::duration_cast<std::chrono::microseconds>(elapsed);
-    } else {
-        qCWarning(scriptengine) << "timerFired -- invalid function" << timerData.function.toVariant().toString();
-    }
-}
-
-QObject* ScriptEngine::setupTimerWithInterval(const QScriptValue& function, int intervalMS, bool isSingleShot) {
-    // create the timer, add it to the map, and start it
-    QTimer* newTimer = new QTimer(this);
-    newTimer->setSingleShot(isSingleShot);
-
-    // The default timer type is not very accurate below about 200ms http://doc.qt.io/qt-5/qt.html#TimerType-enum
-    static const int MIN_TIMEOUT_FOR_COARSE_TIMER = 200;
-    if (intervalMS < MIN_TIMEOUT_FOR_COARSE_TIMER) {
-        newTimer->setTimerType(Qt::PreciseTimer);
-    }
-
-    connect(newTimer, &QTimer::timeout, this, &ScriptEngine::timerFired);
-
-    // make sure the timer stops when the script does
-    connect(this, &ScriptEngine::scriptEnding, newTimer, &QTimer::stop);
-
-
-    CallbackData timerData = { function, currentEntityIdentifier, currentSandboxURL };
-    _timerFunctionMap.insert(newTimer, timerData);
-
-    newTimer->start(intervalMS);
-    return newTimer;
-}
-
-QObject* ScriptEngine::setInterval(const QScriptValue& function, int intervalMS) {
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        scriptWarningMessage("Script.setInterval() while shutting down is ignored... parent script:" + getFilename());
-        return NULL; // bail early
-    }
-
-    return setupTimerWithInterval(function, intervalMS, false);
-}
-
-QObject* ScriptEngine::setTimeout(const QScriptValue& function, int timeoutMS) {
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        scriptWarningMessage("Script.setTimeout() while shutting down is ignored... parent script:" + getFilename());
-        return NULL; // bail early
-    }
-
-    return setupTimerWithInterval(function, timeoutMS, true);
-}
-
-void ScriptEngine::stopTimer(QTimer *timer) {
-    if (_timerFunctionMap.contains(timer)) {
-        timer->stop();
-        _timerFunctionMap.remove(timer);
-        delete timer;
-    } else {
-        qCDebug(scriptengine) << "stopTimer -- not in _timerFunctionMap" << timer;
-    }
-}
-
-QUrl ScriptEngine::resolvePath(const QString& include) const {
-    QUrl url(include);
-    // first lets check to see if it's already a full URL -- or a Windows path like "c:/"
-    if (include.startsWith("/") || url.scheme().length() == 1) {
-        url = QUrl::fromLocalFile(include);
-    }
-    if (!url.isRelative()) {
-        return expandScriptUrl(url);
-    }
-
-    // we apparently weren't a fully qualified url, so, let's assume we're relative
-    // to the first absolute URL in the JS scope chain
-    QUrl parentURL;
-    auto context = currentContext();
-    do {
-        QScriptContextInfo contextInfo { context };
-        parentURL = QUrl(contextInfo.fileName());
-        context = context->parentContext();
-    } while (parentURL.isRelative() && context);
-
-    if (parentURL.isRelative()) {
-        // fallback to the "include" parent (if defined, this will already be absolute)
-        parentURL = QUrl(_parentURL);
-    }
-
-    if (parentURL.isRelative()) {
-        // fallback to the original script engine URL
-        parentURL = QUrl(_fileNameString);
-
-        // if still relative and path-like, then this is probably a local file...
-        if (parentURL.isRelative() && url.path().contains("/")) {
-            parentURL = QUrl::fromLocalFile(_fileNameString);
-        }
-    }
-
-    // at this point we should have a legitimate fully qualified URL for our parent
-    url = expandScriptUrl(parentURL.resolved(url));
-    return url;
-}
-
-QUrl ScriptEngine::resourcesPath() const {
-    return QUrl(PathUtils::resourcesUrl());
-}
-
-void ScriptEngine::print(const QString& message) {
-    emit printedMessage(message, getFilename());
-}
-
-
-void ScriptEngine::beginProfileRange(const QString& label) const {
-    PROFILE_SYNC_BEGIN(script, label.toStdString().c_str(), label.toStdString().c_str());
-}
-
-void ScriptEngine::endProfileRange(const QString& label) const {
-    PROFILE_SYNC_END(script, label.toStdString().c_str(), label.toStdString().c_str());
-}
-
-// Script.require.resolve -- like resolvePath, but performs more validation and throws exceptions on invalid module identifiers (for consistency with Node.js)
-QString ScriptEngine::_requireResolve(const QString& moduleId, const QString& relativeTo) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return QString();
-    }
-    QUrl defaultScriptsLoc = PathUtils::defaultScriptsLocation();
-    QUrl url(moduleId);
-
-    auto displayId = moduleId;
-    if (displayId.length() > MAX_DEBUG_VALUE_LENGTH) {
-        displayId = displayId.mid(0, MAX_DEBUG_VALUE_LENGTH) + "...";
-    }
-    auto message = QString("Cannot find module '%1' (%2)").arg(displayId);
-
-    auto throwResolveError = [&](const QScriptValue& error) -> QString {
-        raiseException(error);
-        maybeEmitUncaughtException("require.resolve");
-        return QString();
-    };
-
-    // de-fuzz the input a little by restricting to rational sizes
-    auto idLength = url.toString().length();
-    if (idLength < 1 || idLength > MAX_MODULE_ID_LENGTH) {
-        auto details = QString("rejecting invalid module id size (%1 chars [1,%2])")
-            .arg(idLength).arg(MAX_MODULE_ID_LENGTH);
-        return throwResolveError(makeError(message.arg(details), "RangeError"));
-    }
-
-    // this regex matches: absolute, dotted or path-like URLs
-    // (ie: the kind of stuff ScriptEngine::resolvePath already handles)
-    QRegularExpression qualified ("^\\w+:|^/|^[.]{1,2}(/|$)");
-
-    // this is for module.require (which is a bound version of require that's always relative to the module path)
-    if (!relativeTo.isEmpty()) {
-        url = QUrl(relativeTo).resolved(moduleId);
-        url = resolvePath(url.toString());
-    } else if (qualified.match(moduleId).hasMatch()) {
-        url = resolvePath(moduleId);
-    } else {
-        // check if the moduleId refers to a "system" module
-        QString systemPath = defaultScriptsLoc.path();
-        QString systemModulePath = QString("%1/modules/%2.js").arg(systemPath).arg(moduleId);
-        url = defaultScriptsLoc;
-        url.setPath(systemModulePath);
-        if (!QFileInfo(url.toLocalFile()).isFile()) {
-            if (!moduleId.contains("./")) {
-                // the user might be trying to refer to a relative file without anchoring it
-                // let's do them a favor and test for that case -- offering specific advice if detected
-                auto unanchoredUrl = resolvePath("./" + moduleId);
-                if (QFileInfo(unanchoredUrl.toLocalFile()).isFile()) {
-                    auto msg = QString("relative module ids must be anchored; use './%1' instead")
-                        .arg(moduleId);
-                    return throwResolveError(makeError(message.arg(msg)));
-                }
-            }
-            return throwResolveError(makeError(message.arg("system module not found")));
-        }
-    }
-
-    if (url.isRelative()) {
-        return throwResolveError(makeError(message.arg("could not resolve module id")));
-    }
-
-    // if it looks like a local file, verify that it's an allowed path and really a file
-    if (url.isLocalFile()) {
-        QFileInfo file(url.toLocalFile());
-        QUrl canonical = url;
-        if (file.exists()) {
-            canonical.setPath(file.canonicalFilePath());
-        }
-
-        bool disallowOutsideFiles = !PathUtils::defaultScriptsLocation().isParentOf(canonical) && !currentSandboxURL.isLocalFile();
-        if (disallowOutsideFiles && !PathUtils::isDescendantOf(canonical, currentSandboxURL)) {
-            return throwResolveError(makeError(message.arg(
-                QString("path '%1' outside of origin script '%2' '%3'")
-                    .arg(PathUtils::stripFilename(url))
-                    .arg(PathUtils::stripFilename(currentSandboxURL))
-                    .arg(canonical.toString())
-            )));
-        }
-        if (!file.exists()) {
-            return throwResolveError(makeError(message.arg("path does not exist: " + url.toLocalFile())));
-        }
-        if (!file.isFile()) {
-            return throwResolveError(makeError(message.arg("path is not a file: " + url.toLocalFile())));
-        }
-    }
-
-    maybeEmitUncaughtException(__FUNCTION__);
-    return url.toString();
-}
-
-// retrieves the current parent module from the JS scope chain
-QScriptValue ScriptEngine::currentModule() {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-    auto jsRequire = globalObject().property("Script").property("require");
-    auto cache = jsRequire.property("cache");
-    auto candidate = QScriptValue();
-    for (auto c = currentContext(); c && !candidate.isObject(); c = c->parentContext()) {
-        QScriptContextInfo contextInfo { c };
-        candidate = cache.property(contextInfo.fileName());
-    }
-    if (!candidate.isObject()) {
-        return QScriptValue();
-    }
-    return candidate;
-}
-
-// replaces or adds "module" to "parent.children[]" array
-// (for consistency with Node.js and userscript cache invalidation without "cache busters")
-bool ScriptEngine::registerModuleWithParent(const QScriptValue& module, const QScriptValue& parent) {
-    auto children = parent.property("children");
-    if (children.isArray()) {
-        auto key = module.property("id");
-        auto length = children.property("length").toInt32();
-        for (int i = 0; i < length; i++) {
-            if (children.property(i).property("id").strictlyEquals(key)) {
-                qCDebug(scriptengine_module) << key.toString() << " updating parent.children[" << i << "] = module";
-                children.setProperty(i, module);
-                return true;
-            }
-        }
-        qCDebug(scriptengine_module) << key.toString() << " appending parent.children[" << length << "] = module";
-        children.setProperty(length, module);
-        return true;
-    } else if (parent.isValid()) {
-        qCDebug(scriptengine_module) << "registerModuleWithParent -- unrecognized parent" << parent.toVariant().toString();
+bool ScriptEngine::IS_THREADSAFE_INVOCATION(const QString& method) {
+    QThread* thread = this->thread();
+    if (QThread::currentThread() == thread) {
+        return true;
     }
+    qCCritical(scriptengine) << QString("Scripting::%1 @ %2 -- ignoring thread-unsafe call from %3")
+                                    .arg(method)
+                                    .arg(thread ? thread->objectName() : "(!thread)")
+                                    .arg(QThread::currentThread()->objectName());
+    qCDebug(scriptengine) << "(please resolve on the calling side by using invokeMethod, executeOnScriptThread, etc.)";
+    Q_ASSERT(false);
     return false;
 }
-
-// creates a new JS "module" Object with default metadata properties
-QScriptValue ScriptEngine::newModule(const QString& modulePath, const QScriptValue& parent) {
-    auto closure = newObject();
-    auto exports = newObject();
-    auto module = newObject();
-    qCDebug(scriptengine_module) << "newModule" << parent.property("filename").toString();
-
-    closure.setProperty("module", module, READONLY_PROP_FLAGS);
-
-    // note: this becomes the "exports" free variable, so should not be set read only
-    closure.setProperty("exports", exports);
-
-    // make the closure available to module instantiation
-    module.setProperty("__closure__", closure, READONLY_HIDDEN_PROP_FLAGS);
-
-    // for consistency with Node.js Module
-    module.setProperty("id", modulePath, READONLY_PROP_FLAGS);
-    module.setProperty("filename", modulePath, READONLY_PROP_FLAGS);
-    module.setProperty("exports", exports); // not readonly
-    module.setProperty("loaded", false, READONLY_PROP_FLAGS);
-    module.setProperty("parent", parent, READONLY_PROP_FLAGS);
-    module.setProperty("children", newArray(), READONLY_PROP_FLAGS);
-
-    // module.require is a bound version of require that always resolves relative to that module's path
-    auto boundRequire = QScriptEngine::evaluate("(function(id) { return Script.require(Script.require.resolve(id, this.filename)); })", "(boundRequire)");
-    module.setProperty("require", boundRequire, READONLY_PROP_FLAGS);
-
-    return module;
-}
-
-// synchronously fetch a module's source code using BatchLoader
-QVariantMap ScriptEngine::fetchModuleSource(const QString& modulePath, const bool forceDownload) {
-    using UrlMap = QMap<QUrl, QString>;
-    auto scriptCache = DependencyManager::get<ScriptCache>();
-    QVariantMap req;
-    qCDebug(scriptengine_module) << "require.fetchModuleSource: " << QUrl(modulePath).fileName() << QThread::currentThread();
-
-    auto onload = [=, &req](const UrlMap& data, const UrlMap& _status) {
-        auto url = modulePath;
-        auto status = _status[url];
-        auto contents = data[url];
-        if (isStopping()) {
-            req["status"] = "Stopped";
-            req["success"] = false;
-        } else {
-            req["url"] = url;
-            req["status"] = status;
-            req["success"] = ScriptCache::isSuccessStatus(status);
-            req["contents"] = contents;
-        }
-    };
-
-    if (forceDownload) {
-        qCDebug(scriptengine_module) << "require.requestScript -- clearing cache for" << modulePath;
-        scriptCache->deleteScript(modulePath);
-    }
-    BatchLoader* loader = new BatchLoader(QList<QUrl>({ modulePath }));
-    connect(loader, &BatchLoader::finished, this, onload);
-    connect(this, &QObject::destroyed, loader, &QObject::deleteLater);
-    // fail faster? (since require() blocks the engine thread while resolving dependencies)
-    const int MAX_RETRIES = 1;
-
-    loader->start(MAX_RETRIES);
-
-    if (!loader->isFinished()) {
-        // This lambda can get called AFTER this local scope has completed.
-        // This is why we pass smart ptrs to the lambda instead of references to local variables.
-        auto monitor = std::make_shared<QTimer>();
-        auto loop = std::make_shared<QEventLoop>();
-        QObject::connect(loader, &BatchLoader::finished, this, [monitor, loop] {
-            monitor->stop();
-            loop->quit();
-        });
-
-        // this helps detect the case where stop() is invoked during the download
-        //  but not seen in time to abort processing in onload()...
-        connect(monitor.get(), &QTimer::timeout, this, [this, loop] {
-            if (isStopping()) {
-                loop->exit(-1);
-            }
-        });
-        monitor->start(500);
-        loop->exec();
-    }
-    loader->deleteLater();
-    return req;
-}
-
-// evaluate a pending module object using the fetched source code
-QScriptValue ScriptEngine::instantiateModule(const QScriptValue& module, const QString& sourceCode) {
-    QScriptValue result;
-    auto modulePath = module.property("filename").toString();
-    auto closure = module.property("__closure__");
-
-    qCDebug(scriptengine_module) << QString("require.instantiateModule: %1 / %2 bytes")
-        .arg(QUrl(modulePath).fileName()).arg(sourceCode.length());
-
-    if (module.property("content-type").toString() == "application/json") {
-        qCDebug(scriptengine_module) << "... parsing as JSON";
-        closure.setProperty("__json", sourceCode);
-        result = evaluateInClosure(closure, { "module.exports = JSON.parse(__json)", modulePath });
-    } else {
-        // scoped vars for consistency with Node.js
-        closure.setProperty("require", module.property("require"));
-        closure.setProperty("__filename", modulePath, READONLY_HIDDEN_PROP_FLAGS);
-        closure.setProperty("__dirname", QString(modulePath).replace(QRegExp("/[^/]*$"), ""), READONLY_HIDDEN_PROP_FLAGS);
-        result = evaluateInClosure(closure, { sourceCode, modulePath });
-    }
-    maybeEmitUncaughtException(__FUNCTION__);
-    return result;
-}
-
-// CommonJS/Node.js like require/module support
-QScriptValue ScriptEngine::require(const QString& moduleId) {
-    qCDebug(scriptengine_module) << "ScriptEngine::require(" << moduleId.left(MAX_DEBUG_VALUE_LENGTH) << ")";
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-
-    auto jsRequire = globalObject().property("Script").property("require");
-    auto cacheMeta = jsRequire.data();
-    auto cache = jsRequire.property("cache");
-    auto parent = currentModule();
-
-    auto throwModuleError = [&](const QString& modulePath, const QScriptValue& error) {
-        cache.setProperty(modulePath, nullValue());
-        if (!error.isNull()) {
-#ifdef DEBUG_JS_MODULES
-            qCWarning(scriptengine_module) << "throwing module error:" << error.toString() << modulePath << error.property("stack").toString();
-#endif
-            raiseException(error);
-        }
-        maybeEmitUncaughtException("module");
-        return unboundNullValue();
-    };
-
-    // start by resolving the moduleId into a fully-qualified path/URL
-    QString modulePath = _requireResolve(moduleId);
-    if (modulePath.isNull() || hasUncaughtException()) {
-        // the resolver already threw an exception -- bail early
-        maybeEmitUncaughtException(__FUNCTION__);
-        return unboundNullValue();
-    }
-
-    // check the resolved path against the cache
-    auto module = cache.property(modulePath);
-
-    // modules get cached in `Script.require.cache` and (similar to Node.js) users can access it
-    // to inspect particular entries and invalidate them by deleting the key:
-    //   `delete Script.require.cache[Script.require.resolve(moduleId)];`
-    
-    // Check to see if we should invalidate the cache based on a user setting.
-    Setting::Handle<bool> getCachebustSetting {"cachebustScriptRequire", false };
-
-    // cacheMeta is just used right now to tell deleted keys apart from undefined ones
-    bool invalidateCache = getCachebustSetting.get() || (module.isUndefined() && cacheMeta.property(moduleId).isValid());
-
-    // reset the cacheMeta record so invalidation won't apply next time, even if the module fails to load
-    cacheMeta.setProperty(modulePath, QScriptValue());
-
-    auto exports = module.property("exports");
-    if (!invalidateCache && exports.isObject()) {
-        // we have found a cached module -- just need to possibly register it with current parent
-        qCDebug(scriptengine_module) << QString("require - using cached module for '%1' (loaded: %2)")
-            .arg(moduleId).arg(module.property("loaded").toString());
-        registerModuleWithParent(module, parent);
-        maybeEmitUncaughtException("cached module");
-        return exports;
-    }
-
-    // bootstrap / register new empty module
-    module = newModule(modulePath, parent);
-    registerModuleWithParent(module, parent);
-
-    // add it to the cache (this is done early so any cyclic dependencies pick up)
-    cache.setProperty(modulePath, module);
-
-    // download the module source
-    auto req = fetchModuleSource(modulePath, invalidateCache);
-
-    if (!req.contains("success") || !req["success"].toBool()) {
-        auto error = QString("error retrieving script (%1)").arg(req["status"].toString());
-        return throwModuleError(modulePath, error);
-    }
-
-#if DEBUG_JS_MODULES
-    qCDebug(scriptengine_module) << "require.loaded: " <<
-        QUrl(req["url"].toString()).fileName() << req["status"].toString();
-#endif
-
-    auto sourceCode = req["contents"].toString();
-
-    if (QUrl(modulePath).fileName().endsWith(".json", Qt::CaseInsensitive)) {
-        module.setProperty("content-type", "application/json");
-    } else {
-        module.setProperty("content-type", "application/javascript");
-    }
-
-    // evaluate the module
-    auto result = instantiateModule(module, sourceCode);
-
-    if (result.isError() && !result.strictlyEquals(module.property("exports"))) {
-        qCWarning(scriptengine_module) << "-- result.isError --" << result.toString();
-        return throwModuleError(modulePath, result);
-    }
-
-    // mark as fully-loaded
-    module.setProperty("loaded", true, READONLY_PROP_FLAGS);
-
-    // set up a new reference point for detecting cache key deletion
-    cacheMeta.setProperty(modulePath, module);
-
-    qCDebug(scriptengine_module) << "//ScriptEngine::require(" << moduleId << ")";
-
-    maybeEmitUncaughtException(__FUNCTION__);
-    return module.property("exports");
-}
-
-// If a callback is specified, the included files will be loaded asynchronously and the callback will be called
-// when all of the files have finished loading.
-// If no callback is specified, the included files will be loaded synchronously and will block execution until
-// all of the files have finished loading.
-void ScriptEngine::include(const QStringList& includeFiles, QScriptValue callback) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return;
-    }
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        scriptWarningMessage("Script.include() while shutting down is ignored... includeFiles:"
-                + includeFiles.join(",") + "parent script:" + getFilename());
-        return; // bail early
-    }
-    QList<QUrl> urls;
-
-    for (QString includeFile : includeFiles) {
-        QString file = DependencyManager::get<ResourceManager>()->normalizeURL(includeFile);
-        QUrl thisURL;
-        bool isStandardLibrary = false;
-        if (file.startsWith("/~/")) {
-            thisURL = expandScriptUrl(QUrl::fromLocalFile(expandScriptPath(file)));
-            QUrl defaultScriptsLoc = PathUtils::defaultScriptsLocation();
-            if (!defaultScriptsLoc.isParentOf(thisURL)) {
-                scriptWarningMessage("Script.include() -- skipping" + file + "-- outside of standard libraries");
-                continue;
-            }
-            isStandardLibrary = true;
-        } else {
-            thisURL = resolvePath(file);
-        }
-
-        bool disallowOutsideFiles = thisURL.isLocalFile() && !isStandardLibrary && !currentSandboxURL.isLocalFile();
-        if (disallowOutsideFiles && !PathUtils::isDescendantOf(thisURL, currentSandboxURL)) {
-            scriptWarningMessage("Script.include() ignoring file path" + thisURL.toString()
-                                + "outside of original entity script" + currentSandboxURL.toString());
-        } else {
-            // We could also check here for CORS, but we don't yet.
-            // It turns out that QUrl.resolve will not change hosts and copy authority, so we don't need to check that here.
-            urls.append(thisURL);
-        }
-    }
-
-    // If there are no URLs left to download, don't bother attempting to download anything and return early
-    if (urls.size() == 0) {
-        return;
-    }
-
-    BatchLoader* loader = new BatchLoader(urls);
-    EntityItemID capturedEntityIdentifier = currentEntityIdentifier;
-    QUrl capturedSandboxURL = currentSandboxURL;
-
-    auto evaluateScripts = [=](const QMap<QUrl, QString>& data, const QMap<QUrl, QString>& status) {
-        auto parentURL = _parentURL;
-        for (QUrl url : urls) {
-            QString contents = data[url];
-            if (contents.isNull()) {
-                scriptErrorMessage("Error loading file (" + status[url] +"): " + url.toString());
-            } else {
-                std::lock_guard<std::recursive_mutex> lock(_lock);
-                if (!_includedURLs.contains(url)) {
-                    _includedURLs << url;
-                    // Set the parent url so that path resolution will be relative
-                    // to this script's url during its initial evaluation
-                    _parentURL = url.toString();
-                    auto operation = [&]() {
-                        evaluate(contents, url.toString());
-                    };
-
-                    doWithEnvironment(capturedEntityIdentifier, capturedSandboxURL, operation);
-                    if (hasUncaughtException()) {
-                        emit unhandledException(cloneUncaughtException("evaluateInclude"));
-                        clearExceptions();
-                    }
-                } else {
-                    scriptPrintedMessage("Script.include() skipping evaluation of previously included url:" + url.toString());
-                }
-            }
-        }
-        _parentURL = parentURL;
-
-        if (callback.isFunction()) {
-            callWithEnvironment(capturedEntityIdentifier, capturedSandboxURL, QScriptValue(callback), QScriptValue(), QScriptValueList());
-        }
-
-        loader->deleteLater();
-    };
-
-    connect(loader, &BatchLoader::finished, this, evaluateScripts);
-
-    // If we are destroyed before the loader completes, make sure to clean it up
-    connect(this, &QObject::destroyed, loader, &QObject::deleteLater);
-
-    loader->start(processLevelMaxRetries);
-
-    if (!callback.isFunction() && !loader->isFinished()) {
-        QEventLoop loop;
-        QObject::connect(loader, &BatchLoader::finished, &loop, &QEventLoop::quit);
-        loop.exec();
-    }
-}
-
-void ScriptEngine::include(const QString& includeFile, QScriptValue callback) {
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        scriptWarningMessage("Script.include() while shutting down is ignored...  includeFile:"
-                    + includeFile + "parent script:" + getFilename());
-        return; // bail early
-    }
-
-    QStringList urls;
-    urls.append(includeFile);
-    include(urls, callback);
-}
-
-// NOTE: The load() command is similar to the include() command except that it loads the script
-// as a stand-alone script. To accomplish this, the ScriptEngine class just emits a signal which
-// the Application or other context will connect to in order to know to actually load the script
-void ScriptEngine::load(const QString& loadFile) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return;
-    }
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (!scriptEngines || scriptEngines->isStopped()) {
-        scriptWarningMessage("Script.load() while shutting down is ignored... loadFile:"
-                + loadFile + "parent script:" + getFilename());
-        return; // bail early
-    }
-    if (!currentEntityIdentifier.isInvalidID()) {
-        scriptWarningMessage("Script.load() from entity script is ignored...  loadFile:"
-                + loadFile + "parent script:" + getFilename() + "entity: " + currentEntityIdentifier.toString());
-        return; // bail early
-    }
-
-    QUrl url = resolvePath(loadFile);
-    if (_isReloading) {
-        auto scriptCache = DependencyManager::get<ScriptCache>();
-        scriptCache->deleteScript(url.toString());
-        emit reloadScript(url.toString(), false);
-    } else {
-        emit loadScript(url.toString(), false);
-    }
-}
-
-// Look up the handler associated with eventName and entityID. If found, evalute the argGenerator thunk and call the handler with those args
-void ScriptEngine::forwardHandlerCall(const EntityItemID& entityID, const QString& eventName, QScriptValueList eventHandlerArgs) {
-    if (QThread::currentThread() != thread()) {
-        qCDebug(scriptengine) << "*** ERROR *** ScriptEngine::forwardHandlerCall() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
-        assert(false);
-        return ;
-    }
-    if (!_registeredHandlers.contains(entityID)) {
-        return;
-    }
-    const RegisteredEventHandlers& handlersOnEntity = _registeredHandlers[entityID];
-    if (!handlersOnEntity.contains(eventName)) {
-        return;
-    }
-    CallbackList handlersForEvent = handlersOnEntity[eventName];
-    if (!handlersForEvent.isEmpty()) {
-        for (int i = 0; i < handlersForEvent.count(); ++i) {
-            // handlersForEvent[i] can contain many handlers that may have each been added by different interface or entity scripts,
-            // and the entity scripts may be for entities other than the one this is a handler for.
-            // Fortunately, the definingEntityIdentifier captured the entity script id (if any) when the handler was added.
-            CallbackData& handler = handlersForEvent[i];
-            callWithEnvironment(handler.definingEntityIdentifier, handler.definingSandboxURL, handler.function, QScriptValue(), eventHandlerArgs);
-        }
-    }
-}
-
-int ScriptEngine::getNumRunningEntityScripts() const {
-    QReadLocker locker { &_entityScriptsLock };
-    int sum = 0;
-    for (const auto& st : _entityScripts) {
-        if (st.status == EntityScriptStatus::RUNNING) {
-            ++sum;
-        }
-    }
-    return sum;
-}
-
-void ScriptEngine::setEntityScriptDetails(const EntityItemID& entityID, const EntityScriptDetails& details) {
-    {
-        QWriteLocker locker { &_entityScriptsLock };
-        _entityScripts[entityID] = details;
-    }
-    emit entityScriptDetailsUpdated();
-}
-
-void ScriptEngine::updateEntityScriptStatus(const EntityItemID& entityID, const EntityScriptStatus &status, const QString& errorInfo) {
-    {
-        QWriteLocker locker { &_entityScriptsLock };
-        EntityScriptDetails& details = _entityScripts[entityID];
-        details.status = status;
-        details.errorInfo = errorInfo;
-    }
-    emit entityScriptDetailsUpdated();
-}
-
-QVariant ScriptEngine::cloneEntityScriptDetails(const EntityItemID& entityID) {
-    static const QVariant NULL_VARIANT { qVariantFromValue((QObject*)nullptr) };
-    QVariantMap map;
-    if (entityID.isNull()) {
-        // TODO: find better way to report JS Error across thread/process boundaries
-        map["isError"] = true;
-        map["errorInfo"] = "Error: getEntityScriptDetails -- invalid entityID";
-    } else {
-#ifdef DEBUG_ENTITY_STATES
-        qDebug() << "cloneEntityScriptDetails" << entityID << QThread::currentThread();
-#endif
-        EntityScriptDetails scriptDetails;
-        if (getEntityScriptDetails(entityID, scriptDetails)) {
-#ifdef DEBUG_ENTITY_STATES
-            qDebug() << "gotEntityScriptDetails" << scriptDetails.status << QThread::currentThread();
-#endif
-            map["isRunning"] = isEntityScriptRunning(entityID);
-            map["status"] = EntityScriptStatus_::valueToKey(scriptDetails.status).toLower();
-            map["errorInfo"] = scriptDetails.errorInfo;
-            map["entityID"] = entityID.toString();
-#ifdef DEBUG_ENTITY_STATES
-            {
-                auto debug = QVariantMap();
-                debug["script"] = scriptDetails.scriptText;
-                debug["scriptObject"] = scriptDetails.scriptObject.toVariant();
-                debug["lastModified"] = (qlonglong)scriptDetails.lastModified;
-                debug["sandboxURL"] = scriptDetails.definingSandboxURL;
-                map["debug"] = debug;
-            }
-#endif
-        } else {
-#ifdef DEBUG_ENTITY_STATES
-            qDebug() << "!gotEntityScriptDetails" <<  QThread::currentThread();
-#endif
-            map["isError"] = true;
-            map["errorInfo"] = "Entity script details unavailable";
-            map["entityID"] = entityID.toString();
-        }
-    }
-    return map;
-}
-
-QFuture<QVariant> ScriptEngine::getLocalEntityScriptDetails(const EntityItemID& entityID) {
-    return QtConcurrent::run(this, &ScriptEngine::cloneEntityScriptDetails, entityID);
-}
-
-bool ScriptEngine::getEntityScriptDetails(const EntityItemID& entityID, EntityScriptDetails &details) const {
-    QReadLocker locker { &_entityScriptsLock };
-    auto it = _entityScripts.constFind(entityID);
-    if (it == _entityScripts.constEnd()) {
-        return false;
-    }
-    details = it.value();
-    return true;
-}
-
-bool ScriptEngine::hasEntityScriptDetails(const EntityItemID& entityID) const {
-    QReadLocker locker { &_entityScriptsLock };
-    return _entityScripts.contains(entityID);
-}
-
-void ScriptEngine::loadEntityScript(const EntityItemID& entityID, const QString& entityScript, bool forceRedownload) {
-    if (QThread::currentThread() != thread()) {
-        QMetaObject::invokeMethod(this, "loadEntityScript",
-            Q_ARG(const EntityItemID&, entityID),
-            Q_ARG(const QString&, entityScript),
-            Q_ARG(bool, forceRedownload)
-        );
-        return;
-    }
-    PROFILE_RANGE(script, __FUNCTION__);
-
-    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
-    if (isStopping() || !scriptEngines || scriptEngines->isStopped()) {
-        qCDebug(scriptengine) << "loadEntityScript.start " << entityID.toString()
-                                     << " but isStopping==" << isStopping()
-                                     << " || engines->isStopped==" << scriptEngines->isStopped();
-        return;
-    }
-
-    if (!hasEntityScriptDetails(entityID)) {
-        // make sure EntityScriptDetails has an entry for this UUID right away
-        // (which allows bailing from the loading/provisioning process early if the Entity gets deleted mid-flight)
-        updateEntityScriptStatus(entityID, EntityScriptStatus::PENDING, "...pending...");
-    }
-
-#ifdef DEBUG_ENTITY_STATES
-    {
-        EntityScriptDetails details;
-        bool hasEntityScript = getEntityScriptDetails(entityID, details);
-        qCDebug(scriptengine) << "loadEntityScript.LOADING: " << entityID.toString()
-            << "(previous: " << (hasEntityScript ? details.status : EntityScriptStatus::PENDING) << ")";
-    }
-#endif
-
-    EntityScriptDetails newDetails;
-    newDetails.scriptText = entityScript;
-    newDetails.status = EntityScriptStatus::LOADING;
-    newDetails.definingSandboxURL = currentSandboxURL;
-    setEntityScriptDetails(entityID, newDetails);
-
-    auto scriptCache = DependencyManager::get<ScriptCache>();
-    // note: see EntityTreeRenderer.cpp for shared pointer lifecycle management
-    QWeakPointer<BaseScriptEngine> weakRef(sharedFromThis());
-    scriptCache->getScriptContents(entityScript,
-        [this, weakRef, entityScript, entityID](const QString& url, const QString& contents, bool isURL, bool success, const QString& status) {
-            QSharedPointer<BaseScriptEngine> strongRef(weakRef);
-            if (!strongRef) {
-                qCWarning(scriptengine) << "loadEntityScript.contentAvailable -- ScriptEngine was deleted during getScriptContents!!";
-                return;
-            }
-            if (isStopping()) {
-#ifdef DEBUG_ENTITY_STATES
-                qCDebug(scriptengine) << "loadEntityScript.contentAvailable -- stopping";
-#endif
-                return;
-            }
-            executeOnScriptThread([=]{
-#ifdef DEBUG_ENTITY_STATES
-                qCDebug(scriptengine) << "loadEntityScript.contentAvailable" << status << entityID.toString();
-#endif
-                if (!isStopping() && hasEntityScriptDetails(entityID)) {
-                    _contentAvailableQueue[entityID] = { entityID, url, contents, isURL, success, status };
-                } else {
-#ifdef DEBUG_ENTITY_STATES
-                    qCDebug(scriptengine) << "loadEntityScript.contentAvailable -- aborting";
-#endif
-                }
-            });
-    }, forceRedownload);
-}
-
-/*@jsdoc
- * Triggered when the script starts for a user. See also, {@link Script.entityScriptPreloadFinished}.
- * <p>Note: Can only be connected to via <code>this.preload = function (...) { ... }</code> in the entity script.</p>
- * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
- * @function Entities.preload
- * @param {Uuid} entityID - The ID of the entity that the script is running in.
- * @returns {Signal}
- * @example <caption>Get the ID of the entity that a client entity script is running in.</caption>
- * var entityScript = (function () {
- *     this.entityID = Uuid.NULL;
- *
- *     this.preload = function (entityID) {
- *         this.entityID = entityID;
- *         print("Entity ID: " + this.entityID);
- *     };
- * });
- *
- * var entityID = Entities.addEntity({
- *     type: "Box",
- *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
- *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
- *     color: { red: 255, green: 0, blue: 0 },
- *     script: "(" + entityScript + ")",  // Could host the script on a Web server instead.
- *     lifetime: 300  // Delete after 5 minutes.
- * });
- */
-// The JSDoc is for the callEntityScriptMethod() call in this method.
-// since all of these operations can be asynch we will always do the actual work in the response handler
-// for the download
-void ScriptEngine::entityScriptContentAvailable(const EntityItemID& entityID, const QString& scriptOrURL, const QString& contents, bool isURL, bool success , const QString& status) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::entityScriptContentAvailable() called on wrong thread ["
-            << QThread::currentThread() << "], invoking on correct thread [" << thread()
-            << "]  " "entityID:" << entityID << "scriptOrURL:" << scriptOrURL << "contents:"
-            << contents << "isURL:" << isURL << "success:" << success;
-#endif
-
-        QMetaObject::invokeMethod(this, "entityScriptContentAvailable",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, scriptOrURL),
-                                  Q_ARG(const QString&, contents),
-                                  Q_ARG(bool, isURL),
-                                  Q_ARG(bool, success),
-                                  Q_ARG(const QString&, status));
-        return;
-    }
-
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::entityScriptContentAvailable() thread [" << QThread::currentThread() << "] expected thread [" << thread() << "]";
-#endif
-
-    auto scriptCache = DependencyManager::get<ScriptCache>();
-    bool isFileUrl = isURL && scriptOrURL.startsWith("file://");
-    auto fileName = isURL ? scriptOrURL : "about:EmbeddedEntityScript";
-
-    QString entityScript;
-    {
-        QWriteLocker locker { &_entityScriptsLock };
-        entityScript = _entityScripts[entityID].scriptText;
-    }
-
-    EntityScriptDetails newDetails;
-    newDetails.scriptText = scriptOrURL;
-
-    // If an error happens below, we want to update newDetails with the new status info
-    // and also abort any pending Entity loads that are waiting on the exact same script URL.
-    auto setError = [&](const QString &errorInfo, const EntityScriptStatus& status) {
-        newDetails.errorInfo = errorInfo;
-        newDetails.status = status;
-        setEntityScriptDetails(entityID, newDetails);
-    };
-
-    // NETWORK / FILESYSTEM ERRORS
-    if (!success) {
-        setError("Failed to load script (" + status + ")", EntityScriptStatus::ERROR_LOADING_SCRIPT);
-        return;
-    }
-
-    // SYNTAX ERRORS
-    auto syntaxError = lintScript(contents, fileName);
-    if (syntaxError.isError()) {
-        auto message = syntaxError.property("formatted").toString();
-        if (message.isEmpty()) {
-            message = syntaxError.toString();
-        }
-        setError(QString("Bad syntax (%1)").arg(message), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        syntaxError.setProperty("detail", entityID.toString());
-        emit unhandledException(syntaxError);
-        return;
-    }
-    QScriptProgram program { contents, fileName };
-    if (program.isNull()) {
-        setError("Bad program (isNull)", EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        emit unhandledException(makeError("program.isNull"));
-        return; // done processing script
-    }
-
-    if (isURL) {
-        setParentURL(scriptOrURL);
-    }
-
-    // SANITY/PERFORMANCE CHECK USING SANDBOX
-    const int SANDBOX_TIMEOUT = 0.25 * MSECS_PER_SECOND;
-    BaseScriptEngine sandbox;
-    sandbox.setProcessEventsInterval(SANDBOX_TIMEOUT);
-    QScriptValue testConstructor, exception;
-    if (atoi(getenv("UNSAFE_ENTITY_SCRIPTS") ? getenv("UNSAFE_ENTITY_SCRIPTS") : "0"))
-    {
-        QTimer timeout;
-        timeout.setSingleShot(true);
-        timeout.start(SANDBOX_TIMEOUT);
-        connect(&timeout, &QTimer::timeout, [=, &sandbox]{
-                qCDebug(scriptengine) << "ScriptEngine::entityScriptContentAvailable timeout";
-
-                // Guard against infinite loops and non-performant code
-                sandbox.raiseException(
-                    sandbox.makeError(QString("Timed out (entity constructors are limited to %1ms)").arg(SANDBOX_TIMEOUT))
-                );
-        });
-
-        testConstructor = sandbox.evaluate(program);
-
-        if (sandbox.hasUncaughtException()) {
-            exception = sandbox.cloneUncaughtException(QString("(preflight %1)").arg(entityID.toString()));
-            sandbox.clearExceptions();
-        } else if (testConstructor.isError()) {
-            exception = testConstructor;
-        }
-    } else {
-        // ENTITY SCRIPT WHITELIST STARTS HERE
-        auto nodeList = DependencyManager::get<NodeList>();
-        bool passList = false;  // assume unsafe
-        QString whitelistPrefix = "[WHITELIST ENTITY SCRIPTS]";
-        QList<QString> safeURLPrefixes = { "file:///", "atp:", "cache:" };
-        safeURLPrefixes += qEnvironmentVariable("EXTRA_WHITELIST").trimmed().split(QRegExp("\\s*,\\s*"), Qt::SkipEmptyParts);
-
-        // Entity Script Whitelist toggle check.
-        Setting::Handle<bool> whitelistEnabled {"private/whitelistEnabled", false };
-                
-        if (!whitelistEnabled.get()) {
-            passList = true;
-        }
-        
-        // Pull SAFEURLS from the Interface.JSON settings.
-        QVariant raw = Setting::Handle<QVariant>("private/settingsSafeURLS").get();
-        QStringList settingsSafeURLS = raw.toString().trimmed().split(QRegExp("\\s*[,\r\n]+\\s*"), Qt::SkipEmptyParts);
-        safeURLPrefixes += settingsSafeURLS;
-        // END Pull SAFEURLS from the Interface.JSON settings.
-        
-        // Get current domain whitelist bypass, in case an entire domain is whitelisted.
-        QString currentDomain = DependencyManager::get<AddressManager>()->getDomainURL().host();
-        
-        QString domainSafeIP = nodeList->getDomainHandler().getHostname();
-        QString domainSafeURL = URL_SCHEME_VIRCADIA + "://" + currentDomain;
-        for (const auto& str : safeURLPrefixes) {
-            if (domainSafeURL.startsWith(str) || domainSafeIP.startsWith(str)) {
-                qCDebug(scriptengine) << whitelistPrefix << "Whitelist Bypassed, entire domain is whitelisted. Current Domain Host: " 
-                    << nodeList->getDomainHandler().getHostname()
-                    << "Current Domain: " << currentDomain;
-                passList = true;
-            }
-        }
-        // END bypass whitelist based on current domain.
-
-        // Start processing scripts through the whitelist.
-        if (ScriptEngine::getContext() == "entity_server") { // If running on the server, do not engage whitelist.
-            passList = true;
-        } else if (!passList) { // If waved through, do not engage whitelist.
-            for (const auto& str : safeURLPrefixes) {
-                qCDebug(scriptengine) << whitelistPrefix << "Script URL: " << scriptOrURL << "TESTING AGAINST" << str << "RESULTS IN"
-                    << scriptOrURL.startsWith(str);
-                if (!str.isEmpty() && scriptOrURL.startsWith(str)) {
-                    passList = true;
-                    qCDebug(scriptengine) << whitelistPrefix << "Script approved.";
-                    break; // Bail early since we found a match.
-                }
-            }
-        }
-        // END processing of scripts through the whitelist.
-
-        if (!passList) { // If the entity failed to pass for any reason, it's blocked and an error is thrown.
-            qCDebug(scriptengine) << whitelistPrefix << "(disabled entity script)" << entityID.toString() << scriptOrURL;
-            exception = makeError("UNSAFE_ENTITY_SCRIPTS == 0");
-        } else {
-            QTimer timeout;
-            timeout.setSingleShot(true);
-            timeout.start(SANDBOX_TIMEOUT);
-            connect(&timeout, &QTimer::timeout, [=, &sandbox] {
-                qCDebug(scriptengine) << "ScriptEngine::entityScriptContentAvailable timeout";
-
-                // Guard against infinite loops and non-performant code
-                sandbox.raiseException(
-                    sandbox.makeError(QString("Timed out (entity constructors are limited to %1ms)").arg(SANDBOX_TIMEOUT)));
-            });
-
-            testConstructor = sandbox.evaluate(program);
-
-            if (sandbox.hasUncaughtException()) {
-                exception = sandbox.cloneUncaughtException(QString("(preflight %1)").arg(entityID.toString()));
-                sandbox.clearExceptions();
-            } else if (testConstructor.isError()) {
-                exception = testConstructor;
-            }
-        }
-      // ENTITY SCRIPT WHITELIST ENDS HERE, uncomment below for original full disabling.
-
-      // qDebug() << "(disabled entity script)" << entityID.toString() << scriptOrURL;
-      // exception = makeError("UNSAFE_ENTITY_SCRIPTS == 0");
-    }
-
-    if (exception.isError()) {
-      // create a local copy using makeError to decouple from the sandbox engine
-      exception = makeError(exception);
-      setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-      emit unhandledException(exception);
-      return;
-    }
-
-    // CONSTRUCTOR VIABILITY
-    if (!testConstructor.isFunction()) {
-        QString testConstructorType = QString(testConstructor.toVariant().typeName());
-        if (testConstructorType == "") {
-            testConstructorType = "empty";
-        }
-        QString testConstructorValue = testConstructor.toString();
-        if (testConstructorValue.size() > MAX_DEBUG_VALUE_LENGTH) {
-            testConstructorValue = testConstructorValue.mid(0, MAX_DEBUG_VALUE_LENGTH) + "...";
-        }
-        auto message = QString("failed to load entity script -- expected a function, got %1, %2")
-            .arg(testConstructorType).arg(testConstructorValue);
-
-        auto err = makeError(message);
-        err.setProperty("fileName", scriptOrURL);
-        err.setProperty("detail", "(constructor " + entityID.toString() + ")");
-
-        setError("Could not find constructor (" + testConstructorType + ")", EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        emit unhandledException(err);
-        return; // done processing script
-    }
-
-    // (this feeds into refreshFileScript)
-    int64_t lastModified = 0;
-    if (isFileUrl) {
-        QString file = QUrl(scriptOrURL).toLocalFile();
-        lastModified = (quint64)QFileInfo(file).lastModified().toMSecsSinceEpoch();
-    }
-
-    // THE ACTUAL EVALUATION AND CONSTRUCTION
-    QScriptValue entityScriptConstructor, entityScriptObject;
-    QUrl sandboxURL = currentSandboxURL.isEmpty() ? scriptOrURL : currentSandboxURL;
-    auto initialization = [&]{
-        entityScriptConstructor = evaluate(contents, fileName);
-        entityScriptObject = entityScriptConstructor.construct();
-
-        if (hasUncaughtException()) {
-            entityScriptObject = cloneUncaughtException("(construct " + entityID.toString() + ")");
-            clearExceptions();
-        }
-    };
-
-    doWithEnvironment(entityID, sandboxURL, initialization);
-
-    if (entityScriptObject.isError()) {
-        auto exception = entityScriptObject;
-        setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
-        emit unhandledException(exception);
-        return;
-    }
-
-    // ... AND WE HAVE LIFTOFF
-    newDetails.status = EntityScriptStatus::RUNNING;
-    newDetails.scriptObject = entityScriptObject;
-    newDetails.lastModified = lastModified;
-    newDetails.definingSandboxURL = sandboxURL;
-    setEntityScriptDetails(entityID, newDetails);
-
-    if (isURL) {
-        setParentURL("");
-    }
-
-    // if we got this far, then call the preload method
-    callEntityScriptMethod(entityID, "preload");
-
-    emit entityScriptPreloadFinished(entityID);
-}
-
-/*@jsdoc
- * Triggered when the script terminates for a user.
- * <p>Note: Can only be connected to via <code>this.unoad = function () { ... }</code> in the entity script.</p>
- * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
- * @function Entities.unload
- * @param {Uuid} entityID - The ID of the entity that the script is running in.
- * @returns {Signal}
- */
-// The JSDoc is for the callEntityScriptMethod() call in this method.
-void ScriptEngine::unloadEntityScript(const EntityItemID& entityID, bool shouldRemoveFromMap) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::unloadEntityScript() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
-            "entityID:" << entityID;
-#endif
-
-        QMetaObject::invokeMethod(this, "unloadEntityScript",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(bool, shouldRemoveFromMap));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::unloadEntityScript() called on correct thread [" << thread() << "]  "
-        "entityID:" << entityID;
-#endif
-
-    EntityScriptDetails oldDetails;
-    if (getEntityScriptDetails(entityID, oldDetails)) {
-        auto scriptText = oldDetails.scriptText;
-
-        if (isEntityScriptRunning(entityID)) {
-            callEntityScriptMethod(entityID, "unload");
-        }
-#ifdef DEBUG_ENTITY_STATES
-        else {
-            qCDebug(scriptengine) << "unload called while !running" << entityID << oldDetails.status;
-        }
-#endif
-        if (shouldRemoveFromMap) {
-            // this was a deleted entity, we've been asked to remove it from the map
-            {
-                QWriteLocker locker { &_entityScriptsLock };
-                _entityScripts.remove(entityID);
-            }
-            emit entityScriptDetailsUpdated();
-        } else if (oldDetails.status != EntityScriptStatus::UNLOADED) {
-            EntityScriptDetails newDetails;
-            newDetails.status = EntityScriptStatus::UNLOADED;
-            newDetails.lastModified = QDateTime::currentMSecsSinceEpoch();
-            // keep scriptText populated for the current need to "debouce" duplicate calls to unloadEntityScript
-            newDetails.scriptText = scriptText;
-            setEntityScriptDetails(entityID, newDetails);
-        }
-
-        stopAllTimersForEntityScript(entityID);
-    }
-}
-
-QList<EntityItemID> ScriptEngine::getListOfEntityScriptIDs() {
-    QReadLocker locker{ &_entityScriptsLock };
-    return _entityScripts.keys();
-}
-
-void ScriptEngine::unloadAllEntityScripts(bool blockingCall) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::unloadAllEntityScripts() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
-#endif
-
-        QMetaObject::invokeMethod(this, "unloadAllEntityScripts",
-            blockingCall ? Qt::BlockingQueuedConnection : Qt::QueuedConnection);
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::unloadAllEntityScripts() called on correct thread [" << thread() << "]";
-#endif
-
-    QList<EntityItemID> keys;
-    {
-        QReadLocker locker{ &_entityScriptsLock };
-        keys = _entityScripts.keys();
-    }
-    foreach(const EntityItemID& entityID, keys) {
-        unloadEntityScript(entityID);
-    }
-    {
-        QWriteLocker locker{ &_entityScriptsLock };
-        _entityScripts.clear();
-    }
-    emit entityScriptDetailsUpdated();
-
-#ifdef DEBUG_ENGINE_STATE
-    _debugDump(
-        "---- CURRENT STATE OF ENGINE: --------------------------",
-        globalObject(),
-        "--------------------------------------------------------"
-    );
-#endif // DEBUG_ENGINE_STATE
-}
-
-void ScriptEngine::refreshFileScript(const EntityItemID& entityID) {
-    if (!HIFI_AUTOREFRESH_FILE_SCRIPTS || !hasEntityScriptDetails(entityID)) {
-        return;
-    }
-
-    static bool recurseGuard = false;
-    if (recurseGuard) {
-        return;
-    }
-    recurseGuard = true;
-
-    EntityScriptDetails details;
-    {
-        QWriteLocker locker { &_entityScriptsLock };
-        details = _entityScripts[entityID];
-    }
-    // Check to see if a file based script needs to be reloaded (easier debugging)
-    if (details.lastModified > 0) {
-        QString filePath = QUrl(details.scriptText).toLocalFile();
-        auto lastModified = QFileInfo(filePath).lastModified().toMSecsSinceEpoch();
-        if (lastModified > details.lastModified) {
-            scriptInfoMessage("Reloading modified script " + details.scriptText);
-            loadEntityScript(entityID, details.scriptText, true);
-        }
-    }
-    recurseGuard = false;
-}
-
-// Execute operation in the appropriate context for (the possibly empty) entityID.
-// Even if entityID is supplied as currentEntityIdentifier, this still documents the source
-// of the code being executed (e.g., if we ever sandbox different entity scripts, or provide different
-// global values for different entity scripts).
-void ScriptEngine::doWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, std::function<void()> operation) {
-    EntityItemID oldIdentifier = currentEntityIdentifier;
-    QUrl oldSandboxURL = currentSandboxURL;
-    currentEntityIdentifier = entityID;
-    currentSandboxURL = sandboxURL;
-
-#if DEBUG_CURRENT_ENTITY
-    QScriptValue oldData = this->globalObject().property("debugEntityID");
-    this->globalObject().setProperty("debugEntityID", entityID.toScriptValue(this)); // Make the entityID available to javascript as a global.
-    operation();
-    this->globalObject().setProperty("debugEntityID", oldData);
-#else
-    operation();
-#endif
-    maybeEmitUncaughtException(!entityID.isNull() ? entityID.toString() : __FUNCTION__);
-    currentEntityIdentifier = oldIdentifier;
-    currentSandboxURL = oldSandboxURL;
-}
-
-void ScriptEngine::callWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, QScriptValue function, QScriptValue thisObject, QScriptValueList args) {
-    auto operation = [&]() {
-        function.call(thisObject, args);
-    };
-    doWithEnvironment(entityID, sandboxURL, operation);
-}
-
-void ScriptEngine::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const QStringList& params, const QUuid& remoteCallerID) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
-            "entityID:" << entityID << "methodName:" << methodName;
-#endif
-
-        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, methodName),
-                                  Q_ARG(const QStringList&, params),
-                                  Q_ARG(const QUuid&, remoteCallerID));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
-        "entityID:" << entityID << "methodName:" << methodName;
-#endif
-
-    if (HIFI_AUTOREFRESH_FILE_SCRIPTS && methodName != "unload") {
-        refreshFileScript(entityID);
-    }
-    if (isEntityScriptRunning(entityID)) {
-        EntityScriptDetails details;
-        {
-            QWriteLocker locker { &_entityScriptsLock };
-            details = _entityScripts[entityID];
-        }
-        QScriptValue entityScript = details.scriptObject; // previously loaded
-
-        // If this is a remote call, we need to check to see if the function is remotely callable
-        // we do this by checking for the existance of the 'remotelyCallable' property on the
-        // entityScript. And we confirm that the method name is included. If this fails, the
-        // function will not be called.
-        bool callAllowed = false;
-        if (remoteCallerID == QUuid()) {
-            callAllowed = true;
-        } else {
-            if (entityScript.property("remotelyCallable").isArray()) {
-                auto callables = entityScript.property("remotelyCallable");
-                auto callableCount = callables.property("length").toInteger();
-                for (int i = 0; i < callableCount; i++) {
-                    auto callable = callables.property(i).toString();
-                    if (callable == methodName) {
-                        callAllowed = true;
-                        break;
-                    }
-                }
-            }
-            if (!callAllowed) {
-                qDebug() << "Method [" << methodName << "] not remotely callable.";
-            }
-        }
-
-        if (callAllowed && entityScript.property(methodName).isFunction()) {
-            QScriptValueList args;
-            args << entityID.toScriptValue(this);
-            args << qScriptValueFromSequence(this, params);
-
-            QScriptValue oldData = this->globalObject().property("Script").property("remoteCallerID");
-            this->globalObject().property("Script").setProperty("remoteCallerID", remoteCallerID.toString()); // Make the remoteCallerID available to javascript as a global.
-            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
-            this->globalObject().property("Script").setProperty("remoteCallerID", oldData);
-        }
-    }
-}
-
-void ScriptEngine::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const PointerEvent& event) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
-            "entityID:" << entityID << "methodName:" << methodName << "event: mouseEvent";
-#endif
-
-        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, methodName),
-                                  Q_ARG(const PointerEvent&, event));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
-        "entityID:" << entityID << "methodName:" << methodName << "event: pointerEvent";
-#endif
-
-    if (HIFI_AUTOREFRESH_FILE_SCRIPTS) {
-        refreshFileScript(entityID);
-    }
-    if (isEntityScriptRunning(entityID)) {
-        EntityScriptDetails details;
-        {
-            QWriteLocker locker { &_entityScriptsLock };
-            details = _entityScripts[entityID];
-        }
-        QScriptValue entityScript = details.scriptObject; // previously loaded
-        if (entityScript.property(methodName).isFunction()) {
-            QScriptValueList args;
-            args << entityID.toScriptValue(this);
-            args << event.toScriptValue(this);
-            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
-        }
-    }
-}
-
-void ScriptEngine::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const EntityItemID& otherID, const Collision& collision) {
-    if (QThread::currentThread() != thread()) {
-#ifdef THREAD_DEBUGGING
-        qCDebug(scriptengine) << "*** WARNING *** ScriptEngine::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
-            "entityID:" << entityID << "methodName:" << methodName << "otherID:" << otherID << "collision: collision";
-#endif
-
-        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
-                                  Q_ARG(const EntityItemID&, entityID),
-                                  Q_ARG(const QString&, methodName),
-                                  Q_ARG(const EntityItemID&, otherID),
-                                  Q_ARG(const Collision&, collision));
-        return;
-    }
-#ifdef THREAD_DEBUGGING
-    qCDebug(scriptengine) << "ScriptEngine::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
-        "entityID:" << entityID << "methodName:" << methodName << "otherID:" << otherID << "collision: collision";
-#endif
-
-    if (HIFI_AUTOREFRESH_FILE_SCRIPTS) {
-        refreshFileScript(entityID);
-    }
-    if (isEntityScriptRunning(entityID)) {
-        EntityScriptDetails details;
-        {
-            QWriteLocker locker { &_entityScriptsLock };
-            details = _entityScripts[entityID];
-        }
-        QScriptValue entityScript = details.scriptObject; // previously loaded
-        if (entityScript.property(methodName).isFunction()) {
-            QScriptValueList args;
-            args << entityID.toScriptValue(this);
-            args << otherID.toScriptValue(this);
-            args << collisionToScriptValue(this, collision);
-            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
-        }
-    }
-}
-
-QString ScriptEngine::getExternalPath(ExternalResource::Bucket bucket, const QString& path) {
-    return ExternalResource::getInstance()->getUrl(bucket, path);
-}
diff --git a/libraries/script-engine/src/ScriptEngine.h b/libraries/script-engine/src/ScriptEngine.h
index 0933025ee18..9708babf831 100644
--- a/libraries/script-engine/src/ScriptEngine.h
+++ b/libraries/script-engine/src/ScriptEngine.h
@@ -16,1006 +16,160 @@
 #ifndef hifi_ScriptEngine_h
 #define hifi_ScriptEngine_h
 
-#include <unordered_map>
-#include <vector>
+#include <memory>
 
+#include <QtCore/QFlags>
 #include <QtCore/QObject>
-#include <QtCore/QUrl>
-#include <QtCore/QSet>
-#include <QtCore/QSharedPointer>
-#include <QtCore/QWaitCondition>
-#include <QtCore/QStringList>
-#include <QMap>
-#include <QMetaEnum>
 
-#include <QtScript/QScriptEngine>
+#include "ScriptValue.h"
 
-#include <AnimationCache.h>
-#include <AnimVariant.h>
-#include <AvatarData.h>
-#include <AvatarHashMap.h>
-#include <LimitedNodeList.h>
-#include <EntityItemID.h>
-#include <EntitiesScriptEngineProvider.h>
-#include <EntityScriptUtils.h>
+class QByteArray;
+class QLatin1String;
+class QString;
+class QThread;
+class QVariant;
+class ScriptContext;
+class ScriptEngine;
+class ScriptManager;
+class ScriptProgram;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+using ScriptProgramPointer = std::shared_ptr<ScriptProgram>;
 
-#include "PointerEvent.h"
-#include "ArrayBufferClass.h"
-#include "AssetScriptingInterface.h"
-#include "AudioScriptingInterface.h"
-#include "BaseScriptEngine.h"
-#include "ExternalResource.h"
-#include "Quat.h"
-#include "Mat4.h"
-#include "ScriptCache.h"
-#include "ScriptUUID.h"
-#include "Vec3.h"
-#include "ConsoleScriptingInterface.h"
-#include "SettingHandle.h"
-#include "Profile.h"
+Q_DECLARE_METATYPE(ScriptEnginePointer);
 
-static const QString NO_SCRIPT("");
+template <typename T>
+inline ScriptValue scriptValueFromValue(ScriptEngine* engine, const T& t);
 
-static const int SCRIPT_FPS = 60;
-static const int DEFAULT_MAX_ENTITY_PPS = 9000;
-static const int DEFAULT_ENTITY_PPS_PER_SCRIPT = 900;
+template <typename T>
+inline T scriptvalue_cast(const ScriptValue& value);
 
-class ScriptEngines;
 
-Q_DECLARE_METATYPE(ScriptEnginePointer)
-
-class CallbackData {
-public:
-    QScriptValue function;
-    EntityItemID definingEntityIdentifier;
-    QUrl definingSandboxURL;
-};
-
-class DeferredLoadEntity {
-public:
-    EntityItemID entityID;
-    QString entityScript;
-    //bool forceRedownload;
-};
-
-struct EntityScriptContentAvailable {
-    EntityItemID entityID;
-    QString scriptOrURL;
-    QString contents;
-    bool isURL;
-    bool success;
-    QString status;
-};
-
-typedef std::unordered_map<EntityItemID, EntityScriptContentAvailable> EntityScriptContentAvailableMap;
-
-typedef QList<CallbackData> CallbackList;
-typedef QHash<QString, CallbackList> RegisteredEventHandlers;
-
-class EntityScriptDetails {
-public:
-    EntityScriptStatus status { EntityScriptStatus::PENDING };
-
-    // If status indicates an error, this contains a human-readable string giving more information about the error.
-    QString errorInfo { "" };
-
-    QString scriptText { "" };
-    QScriptValue scriptObject { QScriptValue() };
-    int64_t lastModified { 0 };
-    QUrl definingSandboxURL { QUrl("about:EntityScript") };
-};
-
-/*@jsdoc
- * The <code>Script</code> API provides facilities for working with scripts.
- *
- * @namespace Script
- *
- * @hifi-interface
- * @hifi-client-entity
- * @hifi-avatar
- * @hifi-server-entity
- * @hifi-assignment-client
- *
- * @property {string} context - The context that the script is running in:
- *     <ul>
- *       <li><code>"client"</code>: An Interface or avatar script.</li>
- *       <li><code>"entity_client"</code>: A client entity script.</li>
- *       <li><code>"entity_server"</code>: A server entity script.</li>
- *       <li><code>"agent"</code>: An assignment client script.</li>
- *     </ul>
- *     <em>Read-only.</em>
- * @property {string} type - The type of script that is running:
- *     <ul>
- *       <li><code>"client"</code>: An Interface script.</li>
- *       <li><code>"entity_client"</code>: A client entity script.</li>
- *       <li><code>"avatar"</code>: An avatar script.</li>
- *       <li><code>"entity_server"</code>: A server entity script.</li>
- *       <li><code>"agent"</code>: An assignment client script.</li>
- *     </ul>
- *     <em>Read-only.</em>
- * @property {string} filename - The filename of the script file.
- *     <em>Read-only.</em>
- * @property {Script.ResourceBuckets} ExternalPaths - External resource buckets.
- */
-/// The main class managing a scripting engine.  Also provides the <code><a href="https://apidocs.vircadia.dev/Script.html">Script</a></code> scripting interface
-class ScriptEngine : public BaseScriptEngine, public EntitiesScriptEngineProvider {
-    Q_OBJECT
-    Q_PROPERTY(QString context READ getContext)
-    Q_PROPERTY(QString type READ getTypeAsString)
-    Q_PROPERTY(QString fileName MEMBER _fileNameString CONSTANT)
+/// [ScriptInterface] Provides an engine-independent interface for QScriptEngine
+class ScriptEngine {
 public:
-
-    enum Context {
-        CLIENT_SCRIPT,
-        ENTITY_CLIENT_SCRIPT,
-        ENTITY_SERVER_SCRIPT,
-        AGENT_SCRIPT
+    typedef ScriptValue (*FunctionSignature)(ScriptContext*, ScriptEngine*);
+    typedef ScriptValue (*MarshalFunction)(ScriptEngine*, const void*);
+    typedef bool (*DemarshalFunction)(const ScriptValue&, void*);
+
+    enum ValueOwnership {
+        QtOwnership = 0,
+        ScriptOwnership = 1,
+        AutoOwnership = 2,
     };
 
-    enum Type {
-        CLIENT,
-        ENTITY_CLIENT,
-        ENTITY_SERVER,
-        AGENT,
-        AVATAR
+    enum QObjectWrapOption {
+        //ExcludeChildObjects	= 0x0001,	// The script object will not expose child objects as properties.
+        ExcludeSuperClassMethods = 0x0002,	// The script object will not expose signals and slots inherited from the superclass.
+        ExcludeSuperClassProperties	= 0x0004,	// The script object will not expose properties inherited from the superclass.
+        ExcludeSuperClassContents = ExcludeSuperClassMethods | ExcludeSuperClassProperties,
+        //ExcludeDeleteLater = 0x0010,	// The script object will not expose the QObject::deleteLater() slot.
+        ExcludeSlots = 0x0020,	// The script object will not expose the QObject's slots.
+        AutoCreateDynamicProperties = 0x0100,	// Properties that don't already exist in the QObject will be created as dynamic properties of that object, rather than as properties of the script object.
+        PreferExistingWrapperObject = 0x0200,	// If a wrapper object with the requested configuration already exists, return that object.
+        SkipMethodsInEnumeration = 0x0008,	// Don't include methods (signals and slots) when enumerating the object's properties.
     };
-    Q_ENUM(Type)
-
-    static int processLevelMaxRetries;
-    ScriptEngine(Context context, const QString& scriptContents = NO_SCRIPT, const QString& fileNameString = QString("about:ScriptEngine"));
-    ~ScriptEngine();
-
-    /// run the script in a dedicated thread. This will have the side effect of evalulating
-    /// the current script contents and calling run(). Callers will likely want to register the script with external
-    /// services before calling this.
-    void runInThread();
-
-    /// run the script in the callers thread, exit when stop() is called.
-    void run();
-
-    QString getFilename() const;
-
-    QList<EntityItemID> getListOfEntityScriptIDs();
-
-    /*@jsdoc
-     * Stops and unloads the current script.
-     * <p><strong>Warning:</strong> If an assignment client script, the script gets restarted after stopping.</p>
-     * @function Script.stop
-     * @param {boolean} [marshal=false] - Marshal.
-     *     <p class="important">Deprecated: This parameter is deprecated and will be removed.</p>
-     * @example <caption>Stop a script after 5s.</caption>
-     * Script.setInterval(function () {
-     *     print("Hello");
-     * }, 1000);
-     *
-     * Script.setTimeout(function () {
-     *     Script.stop(true);
-     * }, 5000);
-     */
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // NOTE - this is intended to be a public interface for Agent scripts, and local scripts, but not for EntityScripts
-    Q_INVOKABLE void stop(bool marshal = false);
-
-    // Stop any evaluating scripts and wait for the scripting thread to finish.
-    void waitTillDoneRunning(bool shutdown = false);
-
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // NOTE - these are NOT intended to be public interfaces available to scripts, the are only Q_INVOKABLE so we can
-    //        properly ensure they are only called on the correct thread
-
-    /*@jsdoc
-     * @function Script.registerGlobalObject
-     * @param {string} name - Name.
-     * @param {object} object - Object.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// registers a global object by name
-    Q_INVOKABLE void registerGlobalObject(const QString& name, QObject* object);
-
-    /*@jsdoc
-     * @function Script.registerGetterSetter
-     * @param {string} name - Name.
-     * @param {function} getter - Getter.
-     * @param {function} setter - Setter.
-     * @param {string} [parent=""] - Parent.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// registers a global getter/setter
-    Q_INVOKABLE void registerGetterSetter(const QString& name, QScriptEngine::FunctionSignature getter,
-                                          QScriptEngine::FunctionSignature setter, const QString& parent = QString(""));
-
-    /*@jsdoc
-     * @function Script.registerFunction
-     * @param {string} name - Name.
-     * @param {function} function - Function.
-     * @param {number} [numArguments=-1] - Number of arguments.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// register a global function
-    Q_INVOKABLE void registerFunction(const QString& name, QScriptEngine::FunctionSignature fun, int numArguments = -1);
-
-    /*@jsdoc
-     * @function Script.registerFunction
-     * @param {string} parent - Parent.
-     * @param {string} name - Name.
-     * @param {function} function - Function.
-     * @param {number} [numArguments=-1] - Number of arguments.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// register a function as a method on a previously registered global object
-    Q_INVOKABLE void registerFunction(const QString& parent, const QString& name, QScriptEngine::FunctionSignature fun,
-                                      int numArguments = -1);
-
-    /*@jsdoc
-     * @function Script.registerEnum
-     * @param {string} name - Name.
-     * @param {object} enum - Enum.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    // WARNING: This function must be called after a registerGlobalObject that creates the namespace this enum is located in, or
-    // the globalObject won't function. E.g., if you have a Foo object and a Foo.FooType enum, Foo must be registered first.
-    /// registers a global enum
-    Q_INVOKABLE void registerEnum(const QString& enumName, QMetaEnum newEnum);
-
-    /*@jsdoc
-     * @function Script.registerValue
-     * @param {string} name - Name.
-     * @param {object} value - Value.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// registers a global object by name
-    Q_INVOKABLE void registerValue(const QString& valueName, QScriptValue value);
+    Q_DECLARE_FLAGS(QObjectWrapOptions, QObjectWrapOption);
 
-    /*@jsdoc
-     * @function Script.evaluate
-     * @param {string} program - Program.
-     * @param {string} filename - File name.
-     * @param {number} [lineNumber=-1] - Line number.
-     * @returns {object} Object.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    /// evaluate some code in the context of the ScriptEngine and return the result
-    Q_INVOKABLE QScriptValue evaluate(const QString& program, const QString& fileName, int lineNumber = 1); // this is also used by the script tool widget
-
-    /*@jsdoc
-     * @function Script.evaluateInClosure
-     * @param {object} locals - Locals.
-     * @param {object} program - Program.
-     * @returns {object} Object.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE QScriptValue evaluateInClosure(const QScriptValue& locals, const QScriptProgram& program);
-
-    /// if the script engine is not already running, this will download the URL and start the process of seting it up
-    /// to run... NOTE - this is used by Application currently to load the url. We don't really want it to be exposed
-    /// to scripts. we may not need this to be invokable
-    void loadURL(const QUrl& scriptURL, bool reload);
-    bool hasValidScriptSuffix(const QString& scriptFileName);
-
-    /*@jsdoc
-     * Gets the context that the script is running in: Interface/avatar, client entity, server entity, or assignment client.
-     * @function Script.getContext
-     * @returns {string} The context that the script is running in:
-     * <ul>
-     *   <li><code>"client"</code>: An Interface or avatar script.</li>
-     *   <li><code>"entity_client"</code>: A client entity script.</li>
-     *   <li><code>"entity_server"</code>: A server entity script.</li>
-     *   <li><code>"agent"</code>: An assignment client script.</li>
-     * </ul>
-     */
-    Q_INVOKABLE QString getContext() const;
-
-    /*@jsdoc
-     * Checks whether the script is running as an Interface or avatar script.
-     * @function Script.isClientScript
-     * @returns {boolean} <code>true</code> if the script is running as an Interface or avatar script, <code>false</code> if it
-     *     isn't.
-     */
-    Q_INVOKABLE bool isClientScript() const { return _context == CLIENT_SCRIPT; }
-
-    /*@jsdoc
-     * Checks whether the application was compiled as a debug build.
-     * @function Script.isDebugMode
-     * @returns {boolean} <code>true</code> if the application was compiled as a debug build, <code>false</code> if it was
-     *     compiled as a release build.
-     */
-    Q_INVOKABLE bool isDebugMode() const;
-
-    /*@jsdoc
-     * Checks whether the script is running as a client entity script.
-     * @function Script.isEntityClientScript
-     * @returns {boolean} <code>true</code> if the script is running as a client entity script, <code>false</code> if it isn't.
-     */
-    Q_INVOKABLE bool isEntityClientScript() const { return _context == ENTITY_CLIENT_SCRIPT; }
-
-    /*@jsdoc
-     * Checks whether the script is running as a server entity script.
-     * @function Script.isEntityServerScript
-     * @returns {boolean} <code>true</code> if the script is running as a server entity script, <code>false</code> if it isn't.
-     */
-    Q_INVOKABLE bool isEntityServerScript() const { return _context == ENTITY_SERVER_SCRIPT; }
-
-    /*@jsdoc
-     * Checks whether the script is running as an assignment client script.
-     * @function Script.isAgentScript
-     * @returns {boolean} <code>true</code> if the script is running as an assignment client script, <code>false</code> if it
-     *     isn't.
-     */
-    Q_INVOKABLE bool isAgentScript() const { return _context == AGENT_SCRIPT; }
-
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // NOTE - these are intended to be public interfaces available to scripts
-
-    /*@jsdoc
-     * Adds a function to the list of functions called when a particular event occurs on a particular entity.
-     * <p>See also, the {@link Entities} API.</p>
-     * @function Script.addEventHandler
-     * @param {Uuid} entityID - The ID of the entity.
-     * @param {Script.EntityEvent} eventName - The name of the event.
-     * @param {Script~entityEventCallback|Script~pointerEventCallback|Script~collisionEventCallback} handler - The function to
-     *     call when the event occurs on the entity. It can be either the name of a function or an in-line definition.
-     * @example <caption>Report when a mouse press occurs on a particular entity.</caption>
-     * var entityID = Entities.addEntity({
-     *     type: "Box",
-     *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
-     *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
-     *     lifetime: 300  // Delete after 5 minutes.
-     * });
-     *
-     * function reportMousePress(entityID, event) {
-     *     print("Mouse pressed on entity: " + JSON.stringify(event));
-     * }
-     *
-     * Script.addEventHandler(entityID, "mousePressOnEntity", reportMousePress);
-     */
-    Q_INVOKABLE void addEventHandler(const EntityItemID& entityID, const QString& eventName, QScriptValue handler);
-
-    /*@jsdoc
-     * Removes a function from the list of functions called when an entity event occurs on a particular entity.
-     * <p>See also, the {@link Entities} API.</p>
-     * @function Script.removeEventHandler
-     * @param {Uuid} entityID - The ID of the entity.
-     * @param {Script.EntityEvent} eventName - The name of the entity event.
-     * @param {function} handler - The name of the function to no longer call when the entity event occurs on the entity.
-     */
-    Q_INVOKABLE void removeEventHandler(const EntityItemID& entityID, const QString& eventName, QScriptValue handler);
-
-    /*@jsdoc
-     * Starts running another script in Interface, if it isn't already running. The script is not automatically loaded next
-     * time Interface starts.
-     * <p class="availableIn"><strong>Supported Script Types:</strong> Interface Scripts &bull; Avatar Scripts</p>
-     * <p>See also, {@link ScriptDiscoveryService.loadScript}.</p>
-     * @function Script.load
-     * @param {string} filename - The URL of the script to load. This can be relative to the current script's URL.
-     * @example <caption>Load a script from another script.</caption>
-     * // First file: scriptA.js
-     * print("This is script A");
-     *
-     * // Second file: scriptB.js
-     * print("This is script B");
-     * Script.load("scriptA.js");
-     *
-     * // If you run scriptB.js you should see both scripts in the Running Scripts dialog.
-     * // And you should see the following output:
-     * // This is script B
-     * // This is script A
-     */
-    Q_INVOKABLE void load(const QString& loadfile);
-
-    /*@jsdoc
-     * Includes JavaScript from other files in the current script. If a callback is specified, the files are loaded and
-     * included asynchronously, otherwise they are included synchronously (i.e., script execution blocks while the files are
-     * included).
-     * @function Script.include
-     * @variation 0
-     * @param {string[]} filenames - The URLs of the scripts to include. Each can be relative to the current script.
-     * @param {function} [callback=null] - The function to call back when the scripts have been included. It can be either the
-     *     name of a function or an in-line definition.
-     */
-    Q_INVOKABLE void include(const QStringList& includeFiles, QScriptValue callback = QScriptValue());
-
-    /*@jsdoc
-     * Includes JavaScript from another file in the current script. If a callback is specified, the file is loaded and included
-     * asynchronously, otherwise it is included synchronously (i.e., script execution blocks while the file is included).
-     * @function Script.include
-     * @param {string} filename - The URL of the script to include. It can be relative to the current script.
-     * @param {function} [callback=null] - The function to call back when the script has been included. It can be either the
-     *     name of a function or an in-line definition.
-     * @example <caption>Include a script file asynchronously.</caption>
-     * // First file: scriptA.js
-     * print("This is script A");
-     *
-     * // Second file: scriptB.js
-     * print("This is script B");
-     * Script.include("scriptA.js", function () {
-     *     print("Script A has been included");
-     * });
-     *
-     * // If you run scriptB.js you should see only scriptB.js in the running scripts list.
-     * // And you should see the following output:
-     * // This is script B
-     * // This is script A
-     * // Script A has been included
-     */
-    Q_INVOKABLE void include(const QString& includeFile, QScriptValue callback = QScriptValue());
-
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // MODULE related methods
-
-    /*@jsdoc
-     * Provides access to methods or objects provided in an external JavaScript or JSON file.
-     * See {@link https://docs.vircadia.com/script/js-tips.html} for further details.
-     * @function Script.require
-     * @param {string} module - The module to use. May be a JavaScript file, a JSON file, or the name of a system module such
-     *     as <code>"appUi"</code> (i.e., the "appUi.js" system module JavaScript file).
-     * @returns {object|array} The value assigned to <code>module.exports</code> in the JavaScript file, or the value defined
-     *     in the JSON file.
-     */
-    Q_INVOKABLE QScriptValue require(const QString& moduleId);
-
-    /*@jsdoc
-     * @function Script.resetModuleCache
-     * @param {boolean} [deleteScriptCache=false] - Delete script cache.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void resetModuleCache(bool deleteScriptCache = false);
-
-    QScriptValue currentModule();
-    bool registerModuleWithParent(const QScriptValue& module, const QScriptValue& parent);
-    QScriptValue newModule(const QString& modulePath, const QScriptValue& parent = QScriptValue());
-    QVariantMap fetchModuleSource(const QString& modulePath, const bool forceDownload = false);
-    QScriptValue instantiateModule(const QScriptValue& module, const QString& sourceCode);
-
-    /*@jsdoc
-     * Calls a function repeatedly, at a set interval.
-     * @function Script.setInterval
-     * @param {function} function - The function to call. This can be either the name of a function or an in-line definition.
-     * @param {number} interval - The interval at which to call the function, in ms.
-     * @returns {object} A handle to the interval timer. This can be used in {@link Script.clearInterval}.
-     * @example <caption>Print a message every second.</caption>
-     * Script.setInterval(function () {
-     *     print("Interval timer fired");
-     * }, 1000);
-    */
-    Q_INVOKABLE QObject* setInterval(const QScriptValue& function, int intervalMS);
-
-    /*@jsdoc
-     * Calls a function once, after a delay.
-     * @function Script.setTimeout
-     * @param {function} function - The function to call. This can be either the name of a function or an in-line definition.
-     * @param {number} timeout - The delay after which to call the function, in ms.
-     * @returns {object} A handle to the timeout timer. This can be used in {@link Script.clearTimeout}.
-     * @example <caption>Print a message once, after a second.</caption>
-     * Script.setTimeout(function () {
-     *     print("Timeout timer fired");
-     * }, 1000);
-     */
-    Q_INVOKABLE QObject* setTimeout(const QScriptValue& function, int timeoutMS);
-
-    /*@jsdoc
-     * Stops an interval timer set by {@link Script.setInterval|setInterval}.
-     * @function Script.clearInterval
-     * @param {object} timer - The interval timer to stop.
-     * @example <caption>Stop an interval timer.</caption>
-     * // Print a message every second.
-     * var timer = Script.setInterval(function () {
-     *     print("Interval timer fired");
-     * }, 1000);
-     *
-     * // Stop the timer after 10 seconds.
-     * Script.setTimeout(function () {
-     *     print("Stop interval timer");
-     *     Script.clearInterval(timer);
-     * }, 10000);
-     */
-    Q_INVOKABLE void clearInterval(QObject* timer) { stopTimer(reinterpret_cast<QTimer*>(timer)); }
-
-    /*@jsdoc
-     * Stops a timeout timer set by {@link Script.setTimeout|setTimeout}.
-     * @function Script.clearTimeout
-     * @param {object} timer - The timeout timer to stop.
-     * @example <caption>Stop a timeout timer.</caption>
-     * // Print a message after two seconds.
-     * var timer = Script.setTimeout(function () {
-     *     print("Timer fired");
-     * }, 2000);
-     *
-     * // Uncomment the following line to stop the timer from firing.
-     * //Script.clearTimeout(timer);
-     */
-    Q_INVOKABLE void clearTimeout(QObject* timer) { stopTimer(reinterpret_cast<QTimer*>(timer)); }
-
-    /*@jsdoc
-     * Prints a message to the program log and emits {@link Script.printedMessage}.
-     * <p>Alternatively, you can use {@link print} or one of the {@link console} API methods.</p>
-     * @function Script.print
-     * @param {string} message - The message to print.
-     */
-    Q_INVOKABLE void print(const QString& message);
-
-    /*@jsdoc
-     * Resolves a relative path to an absolute path. The relative path is relative to the script's location.
-     * @function Script.resolvePath
-     * @param {string} path - The relative path to resolve.
-     * @returns {string} The absolute path.
-     * @example <caption>Report the directory and filename of the running script.</caption>
-     * print(Script.resolvePath(""));
-     * @example <caption>Report the directory of the running script.</caption>
-     * print(Script.resolvePath("."));
-     * @example <caption>Report the path to a file located relative to the running script.</caption>
-     * print(Script.resolvePath("../assets/sounds/hello.wav"));
-     */
-    Q_INVOKABLE QUrl resolvePath(const QString& path) const;
-
-    /*@jsdoc
-     * Gets the path to the resources directory for QML files.
-     * @function Script.resourcesPath
-     * @returns {string} The path to the resources directory for QML files.
-     */
-    Q_INVOKABLE QUrl resourcesPath() const;
-
-    /*@jsdoc
-     * Starts timing a section of code in order to send usage data about it to Vircadia. Shouldn't be used outside of the
-     * standard scripts.
-     * @function Script.beginProfileRange
-     * @param {string} label - A name that identifies the section of code.
-     */
-    Q_INVOKABLE void beginProfileRange(const QString& label) const;
-
-    /*@jsdoc
-     * Finishes timing a section of code in order to send usage data about it to Vircadia. Shouldn't be used outside of
-     * the standard scripts.
-     * @function Script.endProfileRange
-     * @param {string} label - A name that identifies the section of code.
-     */
-    Q_INVOKABLE void endProfileRange(const QString& label) const;
+public:
+    virtual void abortEvaluation() = 0;
+    virtual void clearExceptions() = 0;
+    virtual ScriptValue cloneUncaughtException(const QString& detail = QString()) = 0;
+    virtual ScriptContext* currentContext() const = 0;
+    virtual ScriptValue evaluate(const QString& program, const QString& fileName = QString()) = 0;
+    virtual ScriptValue evaluate(const ScriptProgramPointer &program) = 0;
+    virtual ScriptValue evaluateInClosure(const ScriptValue& locals, const ScriptProgramPointer& program) = 0;
+    virtual ScriptValue globalObject() const = 0;
+    virtual bool hasUncaughtException() const = 0;
+    virtual bool isEvaluating() const = 0;
+    virtual ScriptValue lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber = 1) = 0;
+    virtual ScriptValue makeError(const ScriptValue& other = ScriptValue(), const QString& type = "Error") = 0;
+    virtual ScriptManager* manager() const = 0;
+    virtual bool maybeEmitUncaughtException(const QString& debugHint = QString()) = 0;
+    virtual ScriptValue newArray(uint length = 0) = 0;
+    virtual ScriptValue newArrayBuffer(const QByteArray& message) = 0;
+    virtual ScriptValue newFunction(FunctionSignature fun, int length = 0) = 0;
+    virtual ScriptValue newObject() = 0;
+    virtual ScriptProgramPointer newProgram(const QString& sourceCode, const QString& fileName) = 0;
+    virtual ScriptValue newQObject(QObject *object, ValueOwnership ownership = QtOwnership, const QObjectWrapOptions &options = QObjectWrapOptions()) = 0;
+    virtual ScriptValue newValue(bool value) = 0;
+    virtual ScriptValue newValue(int value) = 0;
+    virtual ScriptValue newValue(uint value) = 0;
+    virtual ScriptValue newValue(double value) = 0;
+    virtual ScriptValue newValue(const QString& value) = 0;
+    virtual ScriptValue newValue(const QLatin1String& value) = 0;
+    virtual ScriptValue newValue(const char* value) = 0;
+    virtual ScriptValue newVariant(const QVariant& value) = 0;
+    virtual ScriptValue nullValue() = 0;
+    virtual bool raiseException(const ScriptValue& exception) = 0;
+    virtual void registerEnum(const QString& enumName, QMetaEnum newEnum) = 0;
+    virtual void registerFunction(const QString& name, FunctionSignature fun, int numArguments = -1) = 0;
+    virtual void registerFunction(const QString& parent, const QString& name, FunctionSignature fun, int numArguments = -1) = 0;
+    virtual void registerGetterSetter(const QString& name, FunctionSignature getter, FunctionSignature setter, const QString& parent = QString("")) = 0;
+    virtual void registerGlobalObject(const QString& name, QObject* object) = 0;
+    virtual void setDefaultPrototype(int metaTypeId, const ScriptValue& prototype) = 0;
+    virtual void setObjectName(const QString& name) = 0;
+    virtual bool setProperty(const char* name, const QVariant& value) = 0;
+    virtual void setProcessEventsInterval(int interval) = 0;
+    virtual QThread* thread() const = 0;
+    virtual void setThread(QThread* thread) = 0;
+    virtual ScriptValue undefinedValue() = 0;
+    virtual ScriptValue uncaughtException() const = 0;
+    virtual QStringList uncaughtExceptionBacktrace() const = 0;
+    virtual int uncaughtExceptionLineNumber() const = 0;
+    virtual void updateMemoryCost(const qint64& deltaSize) = 0;
+    virtual void requestCollectGarbage() = 0;
 
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // Entity Script Related methods
+public:
+    // helper to detect and log warnings when other code invokes QScriptEngine/BaseScriptEngine in thread-unsafe ways
+    bool IS_THREADSAFE_INVOCATION(const QString& method);
 
-    /*@jsdoc
-     * Checks whether an entity has an entity script running.
-     * @function Script.isEntityScriptRunning
-     * @param {Uuid} entityID - The ID of the entity.
-     * @returns {boolean} <code>true</code> if the entity has an entity script running, <code>false</code> if it doesn't.
-     */
-    Q_INVOKABLE bool isEntityScriptRunning(const EntityItemID& entityID) {
-        QReadLocker locker { &_entityScriptsLock };
-        auto it = _entityScripts.constFind(entityID);
-        return it != _entityScripts.constEnd() && it->status == EntityScriptStatus::RUNNING;
+public:
+    template <typename T>
+    inline T fromScriptValue(const ScriptValue& value) {
+        return scriptvalue_cast<T>(value);
     }
-    QVariant cloneEntityScriptDetails(const EntityItemID& entityID);
-    QFuture<QVariant> getLocalEntityScriptDetails(const EntityItemID& entityID) override;
 
-    /*@jsdoc
-     * @function Script.loadEntityScript
-     * @param {Uuid} entityID - Entity ID.
-     * @param {string} script - Script.
-     * @param {boolean} forceRedownload - Force re-download.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void loadEntityScript(const EntityItemID& entityID, const QString& entityScript, bool forceRedownload);
-
-    /*@jsdoc
-     * @function Script.unloadEntityScript
-     * @param {Uuid} entityID - Entity ID.
-     * @param {boolean} [shouldRemoveFromMap=false] - Should remove from map.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void unloadEntityScript(const EntityItemID& entityID, bool shouldRemoveFromMap = false); // will call unload method
-
-    /*@jsdoc
-     * @function Script.unloadAllEntityScripts
-     * @param {boolean} [blockingCall=false] - Wait for completion if call moved to another thread.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void unloadAllEntityScripts(bool blockingCall = false);
-
-    /*@jsdoc
-     * Calls a method in an entity script.
-     * @function Script.callEntityScriptMethod
-     * @param {Uuid} entityID - The ID of the entity running the entity script.
-     * @param {string} methodName - The name of the method to call.
-     * @param {string[]} [parameters=[]] - The parameters to call the specified method with.
-     * @param {Uuid} [remoteCallerID=Uuid.NULL] - An ID that identifies the caller.
-     */
-    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName,
-                                            const QStringList& params = QStringList(),
-                                            const QUuid& remoteCallerID = QUuid()) override;
-
-    /*@jsdoc
-     * Calls a method in an entity script.
-     * @function Script.callEntityScriptMethod
-     * @param {Uuid} entityID - Entity ID.
-     * @param {string} methodName - Method name.
-     * @param {PointerEvent} event - Pointer event.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const PointerEvent& event);
-
-    /*@jsdoc
-     * Calls a method in an entity script.
-     * @function Script.callEntityScriptMethod
-     * @param {Uuid} entityID - Entity ID.
-     * @param {string} methodName - Method name.
-     * @param {Uuid} otherID - Other entity ID.
-     * @param {Collision} collision - Collision.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const EntityItemID& otherID, const Collision& collision);
-
-    /*@jsdoc
-     * Manually runs the JavaScript garbage collector which reclaims memory by disposing of objects that are no longer
-     * reachable.
-     * @function Script.requestGarbageCollection
-     */
-    Q_INVOKABLE void requestGarbageCollection() { collectGarbage(); }
-
-    /*@jsdoc
-     * @function Script.generateUUID
-     * @returns {Uuid} A new UUID.
-     * @deprecated This function is deprecated and will be removed. Use {@link Uuid(0).generate|Uuid.generate} instead.
-     */
-    Q_INVOKABLE QUuid generateUUID() { return QUuid::createUuid(); }
-
-    void setType(Type type) { _type = type; };
-    Type getType() { return _type; };
-    QString getTypeAsString() const;
-
-    bool isFinished() const { return _isFinished; } // used by Application and ScriptWidget
-    bool isRunning() const { return _isRunning; } // used by ScriptWidget
-
-    // this is used by code in ScriptEngines.cpp during the "reload all" operation
-    bool isStopping() const { return _isStopping; }
-
-    void disconnectNonEssentialSignals();
-
-    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-    // These are currently used by Application to track if a script is user loaded or not. Consider finding a solution
-    // inside of Application so that the ScriptEngine class is not polluted by this notion
-    void setUserLoaded(bool isUserLoaded) { _isUserLoaded = isUserLoaded; }
-    bool isUserLoaded() const { return _isUserLoaded; }
-
-    void setQuitWhenFinished(const bool quitWhenFinished) { _quitWhenFinished = quitWhenFinished; }
-    bool isQuitWhenFinished() const { return _quitWhenFinished; }
-
-    // NOTE - this is used by the TypedArray implementation. we need to review this for thread safety
-    ArrayBufferClass* getArrayBufferClass() { return _arrayBufferClass; }
-
-    void setEmitScriptUpdatesFunction(std::function<bool()> func) { _emitScriptUpdates = func; }
-
-    void scriptErrorMessage(const QString& message);
-    void scriptWarningMessage(const QString& message);
-    void scriptInfoMessage(const QString& message);
-    void scriptPrintedMessage(const QString& message);
-    void clearDebugLogWindow();
-    int getNumRunningEntityScripts() const;
-    bool getEntityScriptDetails(const EntityItemID& entityID, EntityScriptDetails &details) const;
-    bool hasEntityScriptDetails(const EntityItemID& entityID) const;
-
-    void setScriptEngines(QSharedPointer<ScriptEngines>& scriptEngines) { _scriptEngines = scriptEngines; }
-
-    /*@jsdoc
-     * Gets the URL for an asset in an external resource bucket. (The location where the bucket is hosted may change over time
-     * but this method will return the asset's current URL.)
-     * @function Script.getExternalPath
-     * @param {Script.ResourceBucket} bucket - The external resource bucket that the asset is in.
-     * @param {string} path - The path within the external resource bucket where the asset is located.
-     *     <p>Normally, this should start with a path or filename to be appended to the bucket URL.
-     *     Alternatively, it can be a relative path starting with <code>./</code> or <code>../</code>, to navigate within the
-     *     resource bucket's URL.</p>
-     * @Returns {string} The URL of an external asset.
-     * @example <caption>Report the URL of a default particle.</caption>
-     * print(Script.getExternalPath(Script.ExternalPaths.Assets, "Bazaar/Assets/Textures/Defaults/Interface/default_particle.png"));
-     * @example <caption>Report the root directory where the Vircadia assets are located.</caption>
-     * print(Script.getExternalPath(Script.ExternalPaths.Assets, "."));
-     */
-    Q_INVOKABLE QString getExternalPath(ExternalResource::Bucket bucket, const QString& path);
-
-public slots:
-
-    /*@jsdoc
-     * @function Script.callAnimationStateHandler
-     * @param {function} callback - Callback function.
-     * @param {object} parameters - Parameters.
-     * @param {string[]} names - Names.
-     * @param {boolean} useNames - Use names.
-     * @param {function} resultHandler - Result handler.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    void callAnimationStateHandler(QScriptValue callback, AnimVariantMap parameters, QStringList names, bool useNames, AnimVariantResultHandler resultHandler);
-
-    /*@jsdoc
-     * @function Script.updateMemoryCost
-     * @param {number} deltaSize - Delta size.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    void updateMemoryCost(const qint64&);
-
-signals:
-
-    /*@jsdoc
-     * @function Script.scriptLoaded
-     * @param {string} filename - File name.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void scriptLoaded(const QString& scriptFilename);
-
-    /*@jsdoc
-     * @function Script.errorLoadingScript
-     * @param {string} filename - File name.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void errorLoadingScript(const QString& scriptFilename);
-
-    /*@jsdoc
-     * Triggered frequently at a system-determined interval.
-     * @function Script.update
-     * @param {number} deltaTime - The time since the last update, in s.
-     * @returns {Signal}
-     * @example <caption>Report script update intervals.</caption>
-     * Script.update.connect(function (deltaTime) {
-     *     print("Update: " + deltaTime);
-     * });
-     */
-    void update(float deltaTime);
-
-    /*@jsdoc
-     * Triggered when the script is stopping.
-     * @function Script.scriptEnding
-     * @returns {Signal}
-     * @example <caption>Report when a script is stopping.</caption>
-     * print("Script started");
-     *
-     * Script.scriptEnding.connect(function () {
-     *     print("Script ending");
-     * });
-     *
-     * Script.setTimeout(function () {
-     *     print("Stopping script");
-     *     Script.stop();
-     * }, 1000);
-     */
-    void scriptEnding();
-
-    /*@jsdoc
-     * @function Script.finished
-     * @param {string} filename - File name.
-     * @param {object} engine - Engine.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void finished(const QString& fileNameString, ScriptEnginePointer);
-
-    /*@jsdoc
-     * @function Script.cleanupMenuItem
-     * @param {string} menuItem - Menu item.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void cleanupMenuItem(const QString& menuItemString);
-
-    /*@jsdoc
-     * Triggered when the script prints a message to the program log via {@link  print}, {@link Script.print},
-     * {@link console.log}, {@link console.debug}, {@link console.group}, {@link console.groupEnd}, {@link console.time}, or
-     * {@link console.timeEnd}.
-     * @function Script.printedMessage
-     * @param {string} message - The message.
-     * @param {string} scriptName - The name of the script that generated the message.
-     * @returns {Signal}
-     */
-    void printedMessage(const QString& message, const QString& scriptName);
-
-    /*@jsdoc
-     * Triggered when the script generates an error, {@link console.error} or {@link console.exception} is called, or
-     * {@link console.assert} is called and fails.
-     * @function Script.errorMessage
-     * @param {string} message - The error message.
-     * @param {string} scriptName - The name of the script that generated the error message.
-     * @returns {Signal}
-     */
-    void errorMessage(const QString& message, const QString& scriptName);
-
-    /*@jsdoc
-     * Triggered when the script generates a warning or {@link console.warn} is called.
-     * @function Script.warningMessage
-     * @param {string} message - The warning message.
-     * @param {string} scriptName - The name of the script that generated the warning message.
-     * @returns {Signal}
-     */
-    void warningMessage(const QString& message, const QString& scriptName);
-
-    /*@jsdoc
-     * Triggered when the script generates an information message or {@link console.info} is called.
-     * @function Script.infoMessage
-     * @param {string} message - The information message.
-     * @param {string} scriptName - The name of the script that generated the information message.
-     * @returns {Signal}
-     */
-    void infoMessage(const QString& message, const QString& scriptName);
-
-    /*@jsdoc
-     * Triggered when the running state of the script changes, e.g., from running to stopping.
-     * @function Script.runningStateChanged
-     * @returns {Signal}
-     */
-    void runningStateChanged();
-
-    /*@jsdoc
-     * @function Script.clearDebugWindow
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void clearDebugWindow();
-
-    /*@jsdoc
-     * @function Script.loadScript
-     * @param {string} scriptName - Script name.
-     * @param {boolean} isUserLoaded - Is user loaded.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void loadScript(const QString& scriptName, bool isUserLoaded);
-
-    /*@jsdoc
-     * @function Script.reloadScript
-     * @param {string} scriptName - Script name.
-     * @param {boolean} isUserLoaded - Is user loaded.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    void reloadScript(const QString& scriptName, bool isUserLoaded);
-
-    /*@jsdoc
-     * Triggered when the script has stopped.
-     * @function Script.doneRunning
-     * @returns {Signal}
-     */
-    void doneRunning();
-
-    /*@jsdoc
-     * @function Script.entityScriptDetailsUpdated
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    // Emitted when an entity script is added or removed, or when the status of an entity
-    // script is updated (goes from RUNNING to ERROR_RUNNING_SCRIPT, for example)
-    void entityScriptDetailsUpdated();
+    template <typename T>
+    inline ScriptValue toScriptValue(const T& value) {
+        return scriptValueFromValue(this, value);
+    }
 
-    /*@jsdoc
-     * Triggered when the script starts for the user. See also, {@link Entities.preload}.
-     * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
-     * @function Script.entityScriptPreloadFinished
-     * @param {Uuid} entityID - The ID of the entity that the script is running in.
-     * @returns {Signal}
-     * @example <caption>Get the ID of the entity that a client entity script is running in.</caption>
-     * var entityScript = function () {
-     *     this.entityID = Uuid.NULL;
-     * };
-     *
-     * Script.entityScriptPreloadFinished.connect(function (entityID) {
-     *     this.entityID = entityID;
-     *     print("Entity ID: " + this.entityID);
-     * });
-     *
-     * var entityID = Entities.addEntity({
-     *     type: "Box",
-     *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
-     *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
-     *     color: { red: 255, green: 0, blue: 0 },
-     *     script: "(" + entityScript + ")",  // Could host the script on a Web server instead.
-     *     lifetime: 300  // Delete after 5 minutes.
-     * });
-     */
-    // Emitted when an entity script has finished running preload
-    void entityScriptPreloadFinished(const EntityItemID& entityID);
+public: // not for public use, but I don't like how Qt strings this along with private friend functions
+    virtual ScriptValue create(int type, const void* ptr) = 0;
+    virtual QVariant convert(const ScriptValue& value, int type) = 0;
+    virtual void registerCustomType(int type, MarshalFunction mf, DemarshalFunction df) = 0;
 
 protected:
-    void init();
-
-    /*@jsdoc
-     * @function Script.executeOnScriptThread
-     * @param {function} function - Function.
-     * @param {ConnectionType} [type=2] - Connection type.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void executeOnScriptThread(std::function<void()> function, const Qt::ConnectionType& type = Qt::QueuedConnection );
-
-    /*@jsdoc
-     * @function Script._requireResolve
-     * @param {string} module - Module.
-     * @param {string} [relativeTo=""] - Relative to.
-     * @returns {string} Result.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    // note: this is not meant to be called directly, but just to have QMetaObject take care of wiring it up in general;
-    //   then inside of init() we just have to do "Script.require.resolve = Script._requireResolve;"
-    Q_INVOKABLE QString _requireResolve(const QString& moduleId, const QString& relativeTo = QString());
-
-    QString logException(const QScriptValue& exception);
-    void timerFired();
-    void stopAllTimers();
-    void stopAllTimersForEntityScript(const EntityItemID& entityID);
-    void refreshFileScript(const EntityItemID& entityID);
-    void updateEntityScriptStatus(const EntityItemID& entityID, const EntityScriptStatus& status, const QString& errorInfo = QString());
-    void setEntityScriptDetails(const EntityItemID& entityID, const EntityScriptDetails& details);
-    void setParentURL(const QString& parentURL) { _parentURL = parentURL; }
-
-    QObject* setupTimerWithInterval(const QScriptValue& function, int intervalMS, bool isSingleShot);
-    void stopTimer(QTimer* timer);
-
-    QHash<EntityItemID, RegisteredEventHandlers> _registeredHandlers;
-    void forwardHandlerCall(const EntityItemID& entityID, const QString& eventName, QScriptValueList eventHanderArgs);
-
-    /*@jsdoc
-     * @function Script.entityScriptContentAvailable
-     * @param {Uuid} entityID - Entity ID.
-     * @param {string} scriptOrURL - Path.
-     * @param {string} contents - Contents.
-     * @param {boolean} isURL - Is a URL.
-     * @param {boolean} success - Success.
-     * @param {string} status - Status.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE void entityScriptContentAvailable(const EntityItemID& entityID, const QString& scriptOrURL, const QString& contents, bool isURL, bool success, const QString& status);
-
-    EntityItemID currentEntityIdentifier; // Contains the defining entity script entity id during execution, if any. Empty for interface script execution.
-    QUrl currentSandboxURL; // The toplevel url string for the entity script that loaded the code being executed, else empty.
-    void doWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, std::function<void()> operation);
-    void callWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, QScriptValue function, QScriptValue thisObject, QScriptValueList args);
-
-    Context _context;
-    Type _type;
-    QString _scriptContents;
-    QString _parentURL;
-    std::atomic<bool> _isFinished { false };
-    std::atomic<bool> _isRunning { false };
-    std::atomic<bool> _isStopping { false };
-    bool _isInitialized { false };
-    QHash<QTimer*, CallbackData> _timerFunctionMap;
-    QSet<QUrl> _includedURLs;
-    mutable QReadWriteLock _entityScriptsLock { QReadWriteLock::Recursive };
-    QHash<EntityItemID, EntityScriptDetails> _entityScripts;
-    EntityScriptContentAvailableMap _contentAvailableQueue;
-
-    bool _isThreaded { false };
-    qint64 _lastUpdate;
-
-    QString _fileNameString;
-    Quat _quatLibrary;
-    Vec3 _vec3Library;
-    Mat4 _mat4Library;
-    ScriptUUID _uuidLibrary;
-    ConsoleScriptingInterface _consoleScriptingInterface;
-    std::atomic<bool> _isUserLoaded { false };
-    bool _isReloading { false };
-
-    std::atomic<bool> _quitWhenFinished;
-
-    ArrayBufferClass* _arrayBufferClass;
-
-    AssetScriptingInterface* _assetScriptingInterface;
-
-    std::function<bool()> _emitScriptUpdates{ []() { return true; }  };
-
-    std::recursive_mutex _lock;
-
-    std::chrono::microseconds _totalTimerExecution { 0 };
-
-    static const QString _SETTINGS_ENABLE_EXTENDED_MODULE_COMPAT;
-    static const QString _SETTINGS_ENABLE_EXTENDED_EXCEPTIONS;
-
-    Setting::Handle<bool> _enableExtendedJSExceptions { _SETTINGS_ENABLE_EXTENDED_EXCEPTIONS, true };
-
-    QWeakPointer<ScriptEngines> _scriptEngines;
+    ~ScriptEngine() {}  // prevent explicit deletion of base class
 };
+Q_DECLARE_OPERATORS_FOR_FLAGS(ScriptEngine::QObjectWrapOptions);
 
-ScriptEnginePointer scriptEngineFactory(ScriptEngine::Context context,
-                                        const QString& scriptContents,
-                                        const QString& fileNameString);
+ScriptEnginePointer newScriptEngine(ScriptManager* manager = nullptr);
+
+// Standardized CPS callback helpers (see: http://fredkschott.com/post/2014/03/understanding-error-first-callbacks-in-node-js/)
+// These two helpers allow async JS APIs that use a callback parameter to be more friendly to scripters by accepting thisObject
+// context and adopting a consistent and intuitable callback signature:
+//   function callback(err, result) { if (err) { ... } else { /* do stuff with result */ } }
+//
+// To use, first pass the user-specified callback args in the same order used with optionally-scoped  Qt signal connections:
+//   auto handler = makeScopedHandlerObject(scopeOrCallback, optionalMethodOrName);
+// And then invoke the scoped handler later per CPS conventions:
+//   auto result = callScopedHandlerObject(handler, err, result);
+ScriptValue makeScopedHandlerObject(const ScriptValue& scopeOrCallback, const ScriptValue& methodOrName);
+ScriptValue callScopedHandlerObject(const ScriptValue& handler, const ScriptValue& err, const ScriptValue& result);
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Inline implementations
+/*
+QThread* ScriptEngine::thread() const {
+    QObject* qobject = toQObject();
+    if (qobject == nullptr) {
+        return nullptr;
+    }
+    return qobject->thread();
+}
+*/
 
-#endif // hifi_ScriptEngine_h
+#endif  // hifi_ScriptEngine_h
 
 /// @}
diff --git a/libraries/script-engine/src/ScriptEngineCast.h b/libraries/script-engine/src/ScriptEngineCast.h
new file mode 100644
index 00000000000..7ab6b02f38d
--- /dev/null
+++ b/libraries/script-engine/src/ScriptEngineCast.h
@@ -0,0 +1,109 @@
+//
+//  ScriptEngineCast.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/9/2021.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptEngineCast_h
+#define hifi_ScriptEngineCast_h
+
+// Object conversion helpers (copied from QScriptEngine)
+
+#include <QtCore/QMetaType>
+
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
+
+template <typename T>
+inline ScriptValue scriptValueFromValue(ScriptEngine* engine, const T& t) {
+    if (!engine) {
+        return ScriptValue();
+    }
+
+    return engine->create(qMetaTypeId<T>(), &t);
+}
+
+template <>
+inline ScriptValue scriptValueFromValue<QVariant>(ScriptEngine* engine, const QVariant& v) {
+    if (!engine) {
+        return ScriptValue();
+    }
+
+    return engine->create(v.userType(), v.data());
+}
+
+template <typename T>
+inline T scriptvalue_cast(const ScriptValue& value) {
+    const int id = qMetaTypeId<T>();
+
+    auto engine = value.engine();
+    if (engine) {
+        QVariant varValue = engine->convert(value, id);
+        if (varValue.isValid()) {
+            return varValue.value<T>();
+        }
+    }
+    if (value.isVariant()) {
+        return qvariant_cast<T>(value.toVariant());
+    }
+
+    return T();
+}
+
+template <>
+inline QVariant scriptvalue_cast<QVariant>(const ScriptValue& value) {
+    return value.toVariant();
+}
+
+template <typename T>
+int scriptRegisterMetaType(ScriptEngine* eng,
+                           ScriptValue (*toScriptValue)(ScriptEngine*, const T& t),
+                           bool (*fromScriptValue)(const ScriptValue&, T& t),
+                           T* = 0)
+{
+    const int id = qRegisterMetaType<T>();  // make sure it's registered
+    eng->registerCustomType(id, reinterpret_cast<ScriptEngine::MarshalFunction>(toScriptValue),
+                            reinterpret_cast<ScriptEngine::DemarshalFunction>(fromScriptValue));
+    return id;
+}
+
+template <class Container>
+ScriptValue scriptValueFromSequence(ScriptEngine* eng, const Container& cont) {
+    ScriptValue a = eng->newArray();
+    typename Container::const_iterator begin = cont.begin();
+    typename Container::const_iterator end = cont.end();
+    typename Container::const_iterator it;
+    quint32 i;
+    for (it = begin, i = 0; it != end; ++it, ++i) {
+        a.setProperty(i, eng->toScriptValue(*it));
+    }
+    return a;
+}
+
+template <class Container>
+bool scriptValueToSequence(const ScriptValue& value, Container& cont) {
+    quint32 len = value.property(QLatin1String("length")).toUInt32();
+    for (quint32 i = 0; i < len; ++i) {
+        ScriptValue item = value.property(i);
+        cont.push_back(scriptvalue_cast<typename Container::value_type>(item));
+    }
+    return true;
+}
+
+template <typename T>
+int scriptRegisterSequenceMetaType(ScriptEngine* engine,
+                                   T* = 0) {
+    return scriptRegisterMetaType<T>(engine, scriptValueFromSequence, scriptValueToSequence);
+}
+
+#endif // hifi_ScriptEngineCast_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptEngines.cpp b/libraries/script-engine/src/ScriptEngines.cpp
index 0e62297905f..ee6e6ffc2f8 100644
--- a/libraries/script-engine/src/ScriptEngines.cpp
+++ b/libraries/script-engine/src/ScriptEngines.cpp
@@ -12,6 +12,7 @@
 #include <QtCore/QSharedPointer>
 
 #include <QtWidgets/QApplication>
+#include <QtCore/QThread>
 
 #include <shared/QtHelpers.h>
 #include <SettingHandle.h>
@@ -19,6 +20,7 @@
 #include <PathUtils.h>
 #include <shared/FileUtils.h>
 
+#include "ScriptCache.h"
 #include "ScriptEngine.h"
 #include "ScriptEngineLogging.h"
 
@@ -65,7 +67,7 @@ void ScriptEngines::onErrorLoadingScript(const QString& url) {
     emit errorLoadingScript(url);
 }
 
-ScriptEngines::ScriptEngines(ScriptEngine::Context context, const QUrl& defaultScriptsOverride)
+ScriptEngines::ScriptEngines(ScriptManager::Context context, const QUrl& defaultScriptsOverride)
     : _context(context), _defaultScriptsOverride(defaultScriptsOverride)
 {
     scriptGatekeeper.initialize();
@@ -138,53 +140,53 @@ QUrl expandScriptUrl(const QUrl& rawScriptURL) {
 
 QObject* scriptsModel();
 
-void ScriptEngines::addScriptEngine(ScriptEnginePointer engine) {
+void ScriptEngines::addScriptEngine(ScriptManagerPointer manager) {
     if (!_isStopped) {
         QMutexLocker locker(&_allScriptsMutex);
-        _allKnownScriptEngines.insert(engine);
+        _allKnownScriptManagers.insert(manager);
     }
 }
 
-void ScriptEngines::removeScriptEngine(ScriptEnginePointer engine) {
+void ScriptEngines::removeScriptEngine(ScriptManagerPointer manager) {
     // If we're not already in the middle of stopping all scripts, then we should remove ourselves
     // from the list of running scripts. We don't do this if we're in the process of stopping all scripts
     // because that method removes scripts from its list as it iterates them
     if (!_isStopped) {
         QMutexLocker locker(&_allScriptsMutex);
-        _allKnownScriptEngines.remove(engine);
+        _allKnownScriptManagers.remove(manager);
     }
 }
 
 void ScriptEngines::shutdownScripting() {
     _isStopped = true;
     QMutexLocker locker(&_allScriptsMutex);
-    qCDebug(scriptengine) << "Stopping all scripts.... currently known scripts:" << _allKnownScriptEngines.size();
+    qCDebug(scriptengine) << "Stopping all scripts.... currently known scripts:" << _allKnownScriptManagers.size();
 
-    QMutableSetIterator<ScriptEnginePointer> i(_allKnownScriptEngines);
+    QMutableSetIterator<ScriptManagerPointer> i(_allKnownScriptManagers);
     while (i.hasNext()) {
-        ScriptEnginePointer scriptEngine = i.next();
-        QString scriptName = scriptEngine->getFilename();
+        ScriptManagerPointer scriptManager = i.next();
+        QString scriptName = scriptManager->getFilename();
 
         // NOTE: typically all script engines are running. But there's at least one known exception to this, the
         // "entities sandbox" which is only used to evaluate entities scripts to test their validity before using
         // them. We don't need to stop scripts that aren't running.
         // TODO: Scripts could be shut down faster if we spread them across a threadpool.
-        if (scriptEngine->isRunning()) {
+        if (scriptManager->isRunning()) {
             qCDebug(scriptengine) << "about to shutdown script:" << scriptName;
 
             // We disconnect any script engine signals from the application because we don't want to do any
             // extra stopScript/loadScript processing that the Application normally does when scripts start
             // and stop. We can safely short circuit this because we know we're in the "quitting" process
-            scriptEngine->disconnect(this);
+            scriptManager->disconnect(this);
 
             // Gracefully stop the engine's scripting thread
-            scriptEngine->stop();
+            scriptManager->stop();
 
             // We need to wait for the engine to be done running before we proceed, because we don't
             // want any of the scripts final "scriptEnding()" or pending "update()" methods from accessing
             // any application state after we leave this stopAllScripts() method
             qCDebug(scriptengine) << "waiting on script:" << scriptName;
-            scriptEngine->waitTillDoneRunning(true);
+            scriptManager->waitTillDoneRunning(true);
             qCDebug(scriptengine) << "done waiting on script:" << scriptName;
         }
         // Once the script is stopped, we can remove it from our set
@@ -372,8 +374,8 @@ void ScriptEngines::saveScripts() {
     QVariantList list;
 
     {
-        QReadLocker lock(&_scriptEnginesHashLock);
-        for (auto it = _scriptEnginesHash.begin(); it != _scriptEnginesHash.end(); ++it) {
+        QReadLocker lock(&_scriptManagersHashLock);
+        for (auto it = _scriptManagersHash.begin(); it != _scriptManagersHash.end(); ++it) {
             // Save user-loaded scripts, only if they are set to quit when finished
             if (it.value() && it.value()->isUserLoaded()  && !it.value()->isQuitWhenFinished()) {
                 auto normalizedUrl = normalizeScriptURL(it.key());
@@ -390,8 +392,8 @@ void ScriptEngines::saveScripts() {
 }
 
 QStringList ScriptEngines::getRunningScripts() {
-    QReadLocker lock(&_scriptEnginesHashLock);
-    QList<QUrl> urls = _scriptEnginesHash.keys();
+    QReadLocker lock(&_scriptManagersHashLock);
+    QList<QUrl> urls = _scriptManagersHash.keys();
     QStringList result;
     for (auto url : urls) {
         result.append(url.toString());
@@ -400,33 +402,33 @@ QStringList ScriptEngines::getRunningScripts() {
 }
 
 void ScriptEngines::stopAllScripts(bool restart) {
-    QReadLocker lock(&_scriptEnginesHashLock);
+    QReadLocker lock(&_scriptManagersHashLock);
 
     if (_isReloading) {
         return;
     }
 
-    for (QHash<QUrl, ScriptEnginePointer>::const_iterator it = _scriptEnginesHash.constBegin();
-        it != _scriptEnginesHash.constEnd(); it++) {
-        ScriptEnginePointer scriptEngine = it.value();
+    for (QHash<QUrl, ScriptManagerPointer>::const_iterator it = _scriptManagersHash.constBegin();
+        it != _scriptManagersHash.constEnd(); it++) {
+        ScriptManagerPointer scriptManager = it.value();
         // skip already stopped scripts
-        if (scriptEngine->isFinished() || scriptEngine->isStopping()) {
+        if (scriptManager->isFinished() || scriptManager->isStopping()) {
             continue;
         }
 
         bool isOverrideScript = it.key().toString().compare(this->_defaultScriptsOverride.toString()) == 0;
         // queue user scripts if restarting
-        if (restart && (scriptEngine->isUserLoaded() || isOverrideScript)) {
+        if (restart && (scriptManager->isUserLoaded() || isOverrideScript)) {
             _isReloading = true;
-            ScriptEngine::Type type = scriptEngine->getType();
+            ScriptManager::Type type = scriptManager->getType();
 
-            connect(scriptEngine.data(), &ScriptEngine::finished, this, [this, type, isOverrideScript] (QString scriptName) {
+            connect(scriptManager.get(), &ScriptManager::finished, this, [this, type, isOverrideScript](QString scriptName) {
                 reloadScript(scriptName, !isOverrideScript)->setType(type);
             });
         }
 
         // stop all scripts
-        scriptEngine->stop();
+        scriptManager->stop();
     }
 
     if (restart) {
@@ -446,23 +448,23 @@ bool ScriptEngines::stopScript(const QString& rawScriptURL, bool restart) {
             scriptURL = normalizeScriptURL(QUrl::fromLocalFile(rawScriptURL));
         }
 
-        QReadLocker lock(&_scriptEnginesHashLock);
-        if (_scriptEnginesHash.contains(scriptURL)) {
-            ScriptEnginePointer scriptEngine = _scriptEnginesHash.value(scriptURL);
+        QReadLocker lock(&_scriptManagersHashLock);
+        if (_scriptManagersHash.contains(scriptURL)) {
+            ScriptManagerPointer scriptManager = _scriptManagersHash.value(scriptURL);
             if (restart) {
-                bool isUserLoaded = scriptEngine->isUserLoaded();
-                ScriptEngine::Type type = scriptEngine->getType();
+                bool isUserLoaded = scriptManager->isUserLoaded();
+                ScriptManager::Type type = scriptManager->getType();
                 auto scriptCache = DependencyManager::get<ScriptCache>();
                 scriptCache->deleteScript(scriptURL);
 
-                if (!scriptEngine->isStopping()) {
-                    connect(scriptEngine.data(), &ScriptEngine::finished,
-                            this, [this, isUserLoaded, type](QString scriptName, ScriptEnginePointer engine) {
+                if (!scriptManager->isStopping()) {
+                    connect(scriptManager.get(), &ScriptManager::finished,
+                            this, [this, isUserLoaded, type](QString scriptName, ScriptManagerPointer manager) {
                             reloadScript(scriptName, isUserLoaded)->setType(type);
                     });
                 }
             }
-            scriptEngine->stop();
+            scriptManager->stop();
             stoppedScript = true;
         }
     }
@@ -480,11 +482,11 @@ void ScriptEngines::reloadAllScripts() {
     stopAllScripts(true);
 }
 
-ScriptEnginePointer ScriptEngines::loadScript(const QUrl& scriptFilename, bool isUserLoaded, bool loadScriptFromEditor,
+ScriptManagerPointer ScriptEngines::loadScript(const QUrl& scriptFilename, bool isUserLoaded, bool loadScriptFromEditor,
                                               bool activateMainWindow, bool reload, bool quitWhenFinished) {
     if (thread() != QThread::currentThread()) {
-        ScriptEnginePointer result { nullptr };
-        BLOCKING_INVOKE_METHOD(this, "loadScript", Q_RETURN_ARG(ScriptEnginePointer, result),
+        ScriptManagerPointer result { nullptr };
+        BLOCKING_INVOKE_METHOD(this, "loadScript", Q_RETURN_ARG(ScriptManagerPointer, result),
             Q_ARG(QUrl, scriptFilename),
             Q_ARG(bool, isUserLoaded),
             Q_ARG(bool, loadScriptFromEditor),
@@ -508,41 +510,41 @@ ScriptEnginePointer ScriptEngines::loadScript(const QUrl& scriptFilename, bool i
 
     scriptUrl = QUrl(FileUtils::selectFile(scriptUrl.toString()));
 
-    auto scriptEngine = getScriptEngine(scriptUrl);
-    if (scriptEngine && !scriptEngine->isStopping()) {
-        return scriptEngine;
+    auto scriptManager = getScriptEngine(scriptUrl);
+    if (scriptManager && !scriptManager->isStopping()) {
+        return scriptManager;
     }
 
-    scriptEngine = scriptEngineFactory(_context, NO_SCRIPT, "about:" + scriptFilename.fileName());
-    scriptEngine->setUserLoaded(isUserLoaded);
-    scriptEngine->setQuitWhenFinished(quitWhenFinished);
+    scriptManager = scriptManagerFactory(_context, NO_SCRIPT, "about:" + scriptFilename.fileName());
+    scriptManager->setUserLoaded(isUserLoaded);
+    scriptManager->setQuitWhenFinished(quitWhenFinished);
 
     if (scriptFilename.isEmpty() || !scriptUrl.isValid()) {
-        launchScriptEngine(scriptEngine);
+        launchScriptEngine(scriptManager);
     } else {
         // connect to the appropriate signals of this script engine
-        connect(scriptEngine.data(), &ScriptEngine::scriptLoaded, this, &ScriptEngines::onScriptEngineLoaded);
-        connect(scriptEngine.data(), &ScriptEngine::errorLoadingScript, this, &ScriptEngines::onScriptEngineError);
+        connect(scriptManager.get(), &ScriptManager::scriptLoaded, this, &ScriptEngines::onScriptEngineLoaded);
+        connect(scriptManager.get(), &ScriptManager::errorLoadingScript, this, &ScriptEngines::onScriptEngineError);
 
         // Shutdown Interface when script finishes, if requested
         if (quitWhenFinished) {
-            connect(scriptEngine.data(), &ScriptEngine::finished, this, &ScriptEngines::quitWhenFinished);
+            connect(scriptManager.get(), &ScriptManager::finished, this, &ScriptEngines::quitWhenFinished);
         }
 
         // get the script engine object to load the script at the designated script URL
-        scriptEngine->loadURL(scriptUrl, reload);
+        scriptManager->loadURL(scriptUrl, reload);
     }
 
-    return scriptEngine;
+    return scriptManager;
 }
 
-ScriptEnginePointer ScriptEngines::getScriptEngine(const QUrl& rawScriptURL) {
-    ScriptEnginePointer result;
+ScriptManagerPointer ScriptEngines::getScriptEngine(const QUrl& rawScriptURL) {
+    ScriptManagerPointer result;
     {
-        QReadLocker lock(&_scriptEnginesHashLock);
+        QReadLocker lock(&_scriptManagersHashLock);
         const QUrl scriptURL = normalizeScriptURL(rawScriptURL);
-        auto it = _scriptEnginesHash.find(scriptURL);
-        if (it != _scriptEnginesHash.end()) {
+        auto it = _scriptManagersHash.find(scriptURL);
+        if (it != _scriptManagersHash.end()) {
             result = it.value();
         }
     }
@@ -552,16 +554,15 @@ ScriptEnginePointer ScriptEngines::getScriptEngine(const QUrl& rawScriptURL) {
 // FIXME - change to new version of ScriptCache loading notification
 void ScriptEngines::onScriptEngineLoaded(const QString& rawScriptURL) {
     UserActivityLogger::getInstance().loadedScript(rawScriptURL);
-    QSharedPointer<BaseScriptEngine> baseScriptEngine = qobject_cast<ScriptEngine*>(sender())->sharedFromThis();
-    ScriptEnginePointer scriptEngine = qSharedPointerCast<ScriptEngine>(baseScriptEngine);
+    ScriptManagerPointer scriptEngine = qobject_cast<ScriptManager*>(sender())->shared_from_this();
 
     launchScriptEngine(scriptEngine);
 
     {
-        QWriteLocker lock(&_scriptEnginesHashLock);
+        QWriteLocker lock(&_scriptManagersHashLock);
         QUrl url = QUrl(rawScriptURL);
         QUrl normalized = normalizeScriptURL(url);
-        _scriptEnginesHash.insert(normalized, scriptEngine);
+        _scriptManagersHash.insert(normalized, scriptEngine);
     }
 
     // Update settings with new script
@@ -573,40 +574,42 @@ void ScriptEngines::quitWhenFinished() {
     qApp->quit();
 }
 
-int ScriptEngines::runScriptInitializers(ScriptEnginePointer scriptEngine) {
-    auto nativeCount = DependencyManager::get<ScriptInitializers>()->runScriptInitializers(scriptEngine.data());
-    return nativeCount + ScriptInitializerMixin<ScriptEnginePointer>::runScriptInitializers(scriptEngine);
+int ScriptEngines::runScriptInitializers(ScriptManagerPointer scriptManager) {
+    auto nativeCount = DependencyManager::get<ScriptInitializers>()->runScriptInitializers(scriptManager->engine().get());
+    return nativeCount + ScriptInitializerMixin<ScriptManagerPointer>::runScriptInitializers(scriptManager);
 }
 
-void ScriptEngines::launchScriptEngine(ScriptEnginePointer scriptEngine) {
-    connect(scriptEngine.data(), &ScriptEngine::finished, this, &ScriptEngines::onScriptFinished, Qt::DirectConnection);
-    connect(scriptEngine.data(), &ScriptEngine::loadScript, [this](const QString& scriptName, bool userLoaded) {
+void ScriptEngines::launchScriptEngine(ScriptManagerPointer scriptManager) {
+    connect(scriptManager.get(), &ScriptManager::finished, this, &ScriptEngines::onScriptFinished, Qt::DirectConnection);
+    connect(scriptManager.get(), &ScriptManager::loadScript,
+            [this](const QString& scriptName, bool userLoaded) {
         loadScript(scriptName, userLoaded);
     });
-    connect(scriptEngine.data(), &ScriptEngine::reloadScript, [this](const QString& scriptName, bool userLoaded) {
+    connect(scriptManager.get(), &ScriptManager::reloadScript,
+            [this](const QString& scriptName, bool userLoaded) {
         loadScript(scriptName, userLoaded, false, false, true);
     });
 
     // register our application services and set it off on its own thread
-    runScriptInitializers(scriptEngine);
-    scriptEngine->runInThread();
+    runScriptInitializers(scriptManager);
+    scriptManager->runInThread();
 }
 
-void ScriptEngines::onScriptFinished(const QString& rawScriptURL, ScriptEnginePointer engine) {
+void ScriptEngines::onScriptFinished(const QString& rawScriptURL, ScriptManagerPointer manager) {
     bool removed = false;
     {
-        QWriteLocker lock(&_scriptEnginesHashLock);
+        QWriteLocker lock(&_scriptManagersHashLock);
         const QUrl scriptURL = normalizeScriptURL(QUrl(rawScriptURL));
-        for (auto it = _scriptEnginesHash.find(scriptURL); it != _scriptEnginesHash.end(); ++it) {
-            if (it.value() == engine) {
-                _scriptEnginesHash.erase(it);
+        for (auto it = _scriptManagersHash.find(scriptURL); it != _scriptManagersHash.end(); ++it) {
+            if (it.value() == manager) {
+                _scriptManagersHash.erase(it);
                 removed = true;
                 break;
             }
         }
     }
 
-    removeScriptEngine(engine);
+    removeScriptEngine(manager);
 
     if (removed && !_isReloading) {
         // Update settings with removed script
diff --git a/libraries/script-engine/src/ScriptEngines.h b/libraries/script-engine/src/ScriptEngines.h
index bc41fb8ab42..f444a32e2d9 100644
--- a/libraries/script-engine/src/ScriptEngines.h
+++ b/libraries/script-engine/src/ScriptEngines.h
@@ -24,14 +24,12 @@
 #include <SettingHandle.h>
 #include <DependencyManager.h>
 #include <shared/ScriptInitializerMixin.h>
+#include "ScriptManager.h"
 
-#include "ScriptEngine.h"
 #include "ScriptsModel.h"
 #include "ScriptsModelFilter.h"
 #include "ScriptGatekeeper.h"
 
-class ScriptEngine;
-
 /*@jsdoc
  * The <code>ScriptDiscoveryService</code> API provides facilities to work with Interface scripts.
  *
@@ -54,7 +52,7 @@ class ScriptEngine;
  *     <em>Read-only.</em>
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/ScriptDiscoveryService.html">ScriptDiscoveryService</a></code> scripting interface
-class ScriptEngines : public QObject, public Dependency, public ScriptInitializerMixin<ScriptEnginePointer> {
+class ScriptEngines : public QObject, public Dependency, public ScriptInitializerMixin<ScriptManagerPointer> {
     Q_OBJECT
 
     Q_PROPERTY(ScriptsModel* scriptsModel READ scriptsModel CONSTANT)
@@ -62,8 +60,8 @@ class ScriptEngines : public QObject, public Dependency, public ScriptInitialize
     Q_PROPERTY(QString debugScriptUrl READ getDebugScriptUrl WRITE setDebugScriptUrl)
 
 public:
-    ScriptEngines(ScriptEngine::Context context, const QUrl& defaultScriptsOverride = QUrl());
-    int runScriptInitializers(ScriptEnginePointer engine) override;
+    ScriptEngines(ScriptManager::Context context, const QUrl& defaultScriptsOverride = QUrl());
+    int runScriptInitializers(ScriptManagerPointer manager) override;
 
     void loadScripts();
     void saveScripts();
@@ -75,7 +73,7 @@ class ScriptEngines : public QObject, public Dependency, public ScriptInitialize
     void reloadLocalFiles();
 
     QStringList getRunningScripts();
-    ScriptEnginePointer getScriptEngine(const QUrl& scriptHash);
+    ScriptManagerPointer getScriptEngine(const QUrl& scriptHash);
 
     ScriptsModel* scriptsModel() { return &_scriptsModel; };
     ScriptsModelFilter* scriptsModelFilter() { return &_scriptsModelFilter; };
@@ -111,7 +109,7 @@ class ScriptEngines : public QObject, public Dependency, public ScriptInitialize
      *     <code>false</code> to not close Interface.
      * @returns {object} An empty object, <code>{}</code>.
      */
-    Q_INVOKABLE ScriptEnginePointer loadScript(const QUrl& scriptFilename = QString(),
+    Q_INVOKABLE ScriptManagerPointer loadScript(const QUrl& scriptFilename = QString(),
         bool isUserLoaded = true, bool loadScriptFromEditor = false, bool activateMainWindow = false, bool reload = false, bool quitWhenFinished = false);
 
     /*@jsdoc
@@ -180,7 +178,7 @@ class ScriptEngines : public QObject, public Dependency, public ScriptInitialize
     void shutdownScripting();
     bool isStopped() const { return _isStopped; }
 
-    void addScriptEngine(ScriptEnginePointer);
+    void addScriptEngine(ScriptManagerPointer);
 
     ScriptGatekeeper scriptGatekeeper;
 
@@ -326,26 +324,24 @@ protected slots:
     /*@jsdoc
      * @function ScriptDiscoveryService.onScriptFinished
      * @param {string} scriptName - Script name.
-     * @param {object} engine - Engine.
+     * @param {object} manager - Script manager.
      * @deprecated This function is deprecated and will be removed.
      */
     // Deprecated because it wasn't intended to be in the API.
-    void onScriptFinished(const QString& fileNameString, ScriptEnginePointer engine);
+    void onScriptFinished(const QString& fileNameString, ScriptManagerPointer manager);
 
 protected:
-    friend class ScriptEngine;
-
-    ScriptEnginePointer reloadScript(const QString& scriptName, bool isUserLoaded = true) { return loadScript(scriptName, isUserLoaded, false, false, true); }
-    void removeScriptEngine(ScriptEnginePointer);
+    ScriptManagerPointer reloadScript(const QString& scriptName, bool isUserLoaded = true) { return loadScript(scriptName, isUserLoaded, false, false, true); }
+    void removeScriptEngine(ScriptManagerPointer);
     void onScriptEngineLoaded(const QString& scriptFilename);
     void quitWhenFinished();
     void onScriptEngineError(const QString& scriptFilename);
-    void launchScriptEngine(ScriptEnginePointer);
+    void launchScriptEngine(ScriptManagerPointer);
 
-    ScriptEngine::Context _context;
-    QReadWriteLock _scriptEnginesHashLock;
-    QMultiHash<QUrl, ScriptEnginePointer> _scriptEnginesHash;
-    QSet<ScriptEnginePointer> _allKnownScriptEngines;
+    ScriptManager::Context _context;
+    QReadWriteLock _scriptManagersHashLock;
+    QMultiHash<QUrl, ScriptManagerPointer> _scriptManagersHash;
+    QSet<ScriptManagerPointer> _allKnownScriptManagers;
     QMutex _allScriptsMutex;
     ScriptsModel _scriptsModel;
     ScriptsModelFilter _scriptsModelFilter;
diff --git a/libraries/script-engine/src/ScriptManager.cpp b/libraries/script-engine/src/ScriptManager.cpp
new file mode 100644
index 00000000000..7addbe080a3
--- /dev/null
+++ b/libraries/script-engine/src/ScriptManager.cpp
@@ -0,0 +1,2478 @@
+//
+//  ScriptManager.cpp
+//  libraries/script-engine/src
+//
+//  Created by Brad Hefta-Gaub on 12/14/13.
+//  Copyright 2013 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptManager.h"
+
+#include <chrono>
+#include <thread>
+
+#include <QtCore/QCoreApplication>
+#include <QtCore/QEventLoop>
+#include <QtCore/QFileInfo>
+#include <QtCore/QTimer>
+#include <QtCore/QThread>
+#include <QtCore/QRegularExpression>
+
+#include <QtCore/QFuture>
+#include <QtConcurrent/QtConcurrentRun>
+
+#include <shared/LocalFileAccessGate.h>
+#include <shared/AbstractLoggerInterface.h>
+#include <DebugDraw.h>
+#include <MessagesClient.h>
+#include <OctreeConstants.h>
+#include <PathUtils.h>
+#include <PortableHighResolutionClock.h>
+#include <ResourceCache.h>
+#include <ResourceManager.h>
+#include <ResourceScriptingInterface.h>
+#include <UserActivityLoggerScriptingInterface.h>
+#include <NodeList.h>
+
+#include "AssetScriptingInterface.h"
+#include "BatchLoader.h"
+#include "EventTypes.h"
+#include "FileScriptingInterface.h" // unzip project
+#include "MenuItemProperties.h"
+#include "ScriptCache.h"
+#include "ScriptContext.h"
+#include "XMLHttpRequestClass.h"
+#include "WebSocketClass.h"
+#include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "ScriptEngineLogging.h"
+#include "ScriptEngines.h"
+#include "StackTestScriptingInterface.h"
+#include "ScriptValue.h"
+#include "ScriptValueIterator.h"
+#include "ScriptValueUtils.h"
+
+#include <Profile.h>
+
+#include "MIDIEvent.h"
+
+#include "SettingHandle.h"
+#include <AddressManager.h>
+#include <NetworkingConstants.h>
+#include <ThreadHelpers.h>
+
+const QString ScriptManager::_SETTINGS_ENABLE_EXTENDED_EXCEPTIONS {
+    "com.highfidelity.experimental.enableExtendedJSExceptions"
+};
+
+const QString ScriptManager::SCRIPT_EXCEPTION_FORMAT{ "[%0] %1 in %2:%3" };
+const QString ScriptManager::SCRIPT_BACKTRACE_SEP{ "\n    " };
+
+static const int MAX_MODULE_ID_LENGTH { 4096 };
+static const int MAX_DEBUG_VALUE_LENGTH { 80 };
+
+static const ScriptValue::PropertyFlags READONLY_PROP_FLAGS{ ScriptValue::ReadOnly | ScriptValue::Undeletable };
+static const ScriptValue::PropertyFlags READONLY_HIDDEN_PROP_FLAGS{ READONLY_PROP_FLAGS | ScriptValue::SkipInEnumeration };
+
+static const bool HIFI_AUTOREFRESH_FILE_SCRIPTS { true };
+
+int scriptManagerPointerMetaID = qRegisterMetaType<ScriptManagerPointer>();
+
+Q_DECLARE_METATYPE(ExternalResource::Bucket);
+
+Q_DECLARE_METATYPE(ScriptValue);
+
+// --- Static script initialization registry
+
+static ScriptManager::StaticInitializerNode* rootInitializer = nullptr;
+
+void ScriptManager::registerNewStaticInitializer(StaticInitializerNode* dest) {
+    // this function is assumed to be called on LoadLibrary, where we are explicitly operating in single-threaded mode
+    // Therefore there is no mutex or threadsafety here and the structure is assumed not to change after loading
+    dest->prev = rootInitializer;
+    rootInitializer = dest;
+}
+static void runStaticInitializers(ScriptManager* manager) {
+    ScriptManager::StaticInitializerNode* here = rootInitializer;
+    while (here != nullptr) {
+        (*here->init)(manager);
+        here = here->prev;
+    }
+}
+
+// ---
+
+static ScriptValue debugPrint(ScriptContext* context, ScriptEngine* engine) {
+    // assemble the message by concatenating our arguments
+    QString message = "";
+    for (int i = 0; i < context->argumentCount(); i++) {
+        if (i > 0) {
+            message += " ";
+        }
+        message += context->argument(i).toString();
+    }
+
+    // was this generated by a script engine? If we don't recognize it then send the message and exit
+    ScriptManager* scriptManager = engine->manager();
+    if (!scriptManager) {
+        qCDebug(scriptengine_script, "%s", qUtf8Printable(message));
+        return ScriptValue();
+    }
+
+    // This message was sent by one of our script engines, let's try to see if we can find the source.
+    // Note that the first entry in the backtrace should be "print" and is somewhat useless to us
+    AbstractLoggerInterface* loggerInterface = AbstractLoggerInterface::get();
+    if (loggerInterface && loggerInterface->showSourceDebugging()) {
+        ScriptContext* userContext = context;
+        ScriptContextPointer parentContext; // using this variable to maintain parent variable lifespan
+        while (userContext && userContext->functionContext()->functionType() == ScriptFunctionContext::NativeFunction) {
+            parentContext = userContext->parentContext();
+            userContext = parentContext.get();
+        }
+        QString location;
+        if (userContext) {
+            auto contextInfo = userContext->functionContext();
+            QString fileName = contextInfo->fileName();
+            int lineNumber = contextInfo->lineNumber();
+            QString functionName = contextInfo->functionName();
+    
+            location = functionName;
+            if (!fileName.isEmpty()) {
+                if (location.isEmpty()) {
+                    location = fileName;
+                } else {
+                    location = QString("%1 at %2").arg(location).arg(fileName);
+                }
+            }
+            if (lineNumber != -1) {
+                location = QString("%1:%2").arg(location).arg(lineNumber);
+            }
+        }
+        if (location.isEmpty()) {
+            location = scriptManager->getFilename();
+        }
+    
+        // give the script engine a chance to notify the system about this message
+        scriptManager->print(message);
+    
+        // send the message to debug log
+        qCDebug(scriptengine_script, "[%s] %s", qUtf8Printable(location), qUtf8Printable(message));
+    } else {
+        scriptManager->print(message);
+        // prefix the script engine name to help disambiguate messages in the main debug log
+        qCDebug(scriptengine_script, "[%s] %s", qUtf8Printable(scriptManager->getFilename()), qUtf8Printable(message));
+    }
+
+    return ScriptValue();
+}
+
+// FIXME Come up with a way to properly encode entity IDs in filename
+// The purpose of the following two function is to embed entity ids into entity script filenames
+// so that they show up in stacktraces
+//
+// Extract the url portion of a url that has been encoded with encodeEntityIdIntoEntityUrl(...)
+QString extractUrlFromEntityUrl(const QString& url) {
+    auto parts = url.split(' ', Qt::SkipEmptyParts);
+    if (parts.length() > 0) {
+        return parts[0];
+    } else {
+        return "";
+    }
+}
+
+// Encode an entity id into an entity url
+// Example: http://www.example.com/some/path.js [EntityID:{9fdd355f-d226-4887-9484-44432d29520e}]
+QString encodeEntityIdIntoEntityUrl(const QString& url, const QString& entityID) {
+    return url + " [EntityID:" + entityID + "]";
+}
+
+QString ScriptManager::logException(const ScriptValue& exception) {
+    auto message = formatException(exception, _enableExtendedJSExceptions.get());
+    scriptErrorMessage(message);
+    return message;
+}
+
+ScriptManagerPointer scriptManagerFactory(ScriptManager::Context context,
+                                                 const QString& scriptContents,
+                                                 const QString& fileNameString) {
+    ScriptManagerPointer manager = newScriptManager(context, scriptContents, fileNameString);
+    auto scriptEngines = DependencyManager::get<ScriptEngines>();
+    scriptEngines->addScriptEngine(manager);
+    manager->setScriptEngines(scriptEngines);
+    return manager;
+}
+
+ScriptManagerPointer newScriptManager(ScriptManager::Context context,
+                                      const QString& scriptContents,
+                                      const QString& fileNameString) {
+    ScriptManagerPointer manager(new ScriptManager(context, scriptContents, fileNameString),
+                                 [](ScriptManager* obj) { obj->deleteLater(); });
+    ScriptEnginePointer engine = newScriptEngine(manager.get());
+    manager->_engine = engine;
+    return manager;
+}
+
+int ScriptManager::processLevelMaxRetries { ScriptRequest::MAX_RETRIES };
+ScriptManager::ScriptManager(Context context, const QString& scriptContents, const QString& fileNameString) :
+    QObject(),
+    _context(context),
+    _scriptContents(scriptContents),
+    _timerFunctionMap(),
+    _fileNameString(fileNameString),
+    _assetScriptingInterface(new AssetScriptingInterface(this)),
+    _engine(newScriptEngine(this))
+{
+    switch (_context) {
+        case Context::CLIENT_SCRIPT:
+            _type = Type::CLIENT;
+            break;
+        case Context::ENTITY_CLIENT_SCRIPT:
+            _type = Type::ENTITY_CLIENT;
+            break;
+        case Context::ENTITY_SERVER_SCRIPT:
+            _type = Type::ENTITY_SERVER;
+            break;
+        case Context::AGENT_SCRIPT:
+            _type = Type::AGENT;
+            break;
+    }
+
+    if (isEntityServerScript()) {
+        qCDebug(scriptengine) << "isEntityServerScript() -- limiting maxRetries to 1";
+        processLevelMaxRetries = 1;
+    }
+
+    // this is where all unhandled exceptions end up getting logged
+    connect(this, &ScriptManager::unhandledException, this, [this](const ScriptValue& err) {
+        auto output = err.engine() == _engine ? err : _engine->makeError(err);
+        if (!output.property("detail").isValid()) {
+            output.setProperty("detail", "UnhandledException");
+        }
+        logException(output);
+    });
+
+    if (_type == Type::ENTITY_CLIENT || _type == Type::ENTITY_SERVER) {
+        QObject::connect(this, &ScriptManager::update, this, [this]() {
+            // process pending entity script content
+            if (!_contentAvailableQueue.empty() && !(_isFinished || _isStopping)) {
+                EntityScriptContentAvailableMap pending;
+                std::swap(_contentAvailableQueue, pending);
+                for (auto& pair : pending) {
+                    auto& args = pair.second;
+                    entityScriptContentAvailable(args.entityID, args.scriptOrURL, args.contents, args.isURL, args.success, args.status);
+                }
+            }
+        });
+    }
+}
+
+QString ScriptManager::getTypeAsString() const {
+    auto value = QVariant::fromValue(_type).toString();
+    return value.isEmpty() ? "unknown" : value.toLower();
+}
+
+QString ScriptManager::getContext() const {
+    switch (_context) {
+        case CLIENT_SCRIPT:
+            return "client";
+        case ENTITY_CLIENT_SCRIPT:
+            return "entity_client";
+        case ENTITY_SERVER_SCRIPT:
+            return "entity_server";
+        case AGENT_SCRIPT:
+            return "agent";
+        default:
+            return "unknown";
+    }
+    return "unknown";
+}
+
+bool ScriptManager::isDebugMode() const {
+#if defined(DEBUG)
+    return true;
+#else
+    return false;
+#endif
+}
+
+ScriptManager::~ScriptManager() {}
+
+void ScriptManager::disconnectNonEssentialSignals() {
+    disconnect();
+    QThread* workerThread;
+    // Ensure the thread should be running, and does exist
+    if (_isRunning && _isThreaded && (workerThread = thread())) {
+        connect(this, &QObject::destroyed, workerThread, &QThread::quit);
+        connect(workerThread, &QThread::finished, workerThread, &QObject::deleteLater);
+    }
+}
+
+void ScriptManager::runInThread() {
+    Q_ASSERT_X(!_isThreaded, "ScriptManager::runInThread()", "runInThread should not be called more than once");
+
+    if (_isThreaded) {
+        return;
+    }
+
+    _isThreaded = true;
+
+    // The thread interface cannot live on itself, and we want to move this into the thread, so
+    // the thread cannot have this as a parent.
+    QThread* workerThread = new QThread();
+    QString name = QString("js:") + getFilename().replace("about:","");
+    workerThread->setObjectName(name);
+    _engine->setThread(workerThread);
+    moveToThread(workerThread);
+
+    // NOTE: If you connect any essential signals for proper shutdown or cleanup of
+    // the script engine, make sure to add code to "reconnect" them to the
+    // disconnectNonEssentialSignals() method
+    connect(workerThread, &QThread::started, this, [this, name] {
+        setThreadName(name.toStdString());
+        run();
+    });
+    connect(this, &QObject::destroyed, workerThread, &QThread::quit);
+    connect(workerThread, &QThread::finished, workerThread, &QObject::deleteLater);
+
+    workerThread->start();
+}
+
+void ScriptManager::executeOnScriptThread(std::function<void()> function, const Qt::ConnectionType& type ) {
+    if (QThread::currentThread() != thread()) {
+        QMetaObject::invokeMethod(this, "executeOnScriptThread", type, Q_ARG(std::function<void()>, function));
+        return;
+    }
+
+    function();
+}
+
+void ScriptManager::waitTillDoneRunning(bool shutdown) {
+    // Engine should be stopped already, but be defensive
+    stop();
+    
+    auto workerThread = thread();
+    
+    if (workerThread == QThread::currentThread()) {
+        qCWarning(scriptengine) << "ScriptManager::waitTillDoneRunning called, but the script is on the same thread:" << getFilename();
+        return;
+    }
+    
+    if (_isThreaded && workerThread) {
+        // We should never be waiting (blocking) on our own thread
+        assert(workerThread != QThread::currentThread());
+
+#if 0
+        // 26 Feb 2021 - Disabled this OSX-specific code because it causes OSX to crash on shutdown; without this code, OSX 
+        // doesn't crash on shutdown. Qt 5.12.3 and Qt 5.15.2.
+        //
+        // On mac, don't call QCoreApplication::processEvents() here. This is to prevent
+        // [NSApplication terminate:] from prematurely destroying the static destructors
+        // while we are waiting for the scripts to shutdown. We will pump the message
+        // queue later in the Application destructor.
+        if (workerThread->isRunning()) {
+            workerThread->quit();
+
+            if (_engine->isEvaluating()) {
+                qCWarning(scriptengine) << "Script Engine has been running too long, aborting:" << getFilename();
+                _engine->abortEvaluation();
+            } else {
+                auto context = _engine->currentContext();
+                if (context) {
+                    qCWarning(scriptengine) << "Script Engine has been running too long, throwing:" << getFilename();
+                    context->throwError("Timed out during shutdown");
+                }
+            }
+
+            // Wait for the scripting thread to stop running, as
+            // flooding it with aborts/exceptions will persist it longer
+            static const auto MAX_SCRIPT_QUITTING_TIME = 0.5 * MSECS_PER_SECOND;
+            if (!workerThread->wait(MAX_SCRIPT_QUITTING_TIME)) {
+                workerThread->terminate();
+            }
+        }
+#else
+        auto startedWaiting = usecTimestampNow();
+        while (workerThread->isRunning()) {
+            // If the final evaluation takes too long, then tell the script engine to stop running
+            auto elapsedUsecs = usecTimestampNow() - startedWaiting;
+            static const auto MAX_SCRIPT_EVALUATION_TIME = USECS_PER_SECOND;
+            if (elapsedUsecs > MAX_SCRIPT_EVALUATION_TIME) {
+                workerThread->quit();
+
+                if (_engine->isEvaluating()) {
+                    qCWarning(scriptengine) << "Script Engine has been running too long, aborting:" << getFilename();
+                    _engine->abortEvaluation();
+                } else {
+                    auto context = _engine->currentContext();
+                    if (context) {
+                        qCWarning(scriptengine) << "Script Engine has been running too long, throwing:" << getFilename();
+                        context->throwError("Timed out during shutdown");
+                    }
+                }
+
+                // Wait for the scripting thread to stop running, as
+                // flooding it with aborts/exceptions will persist it longer
+                static const auto MAX_SCRIPT_QUITTING_TIME = 0.5 * MSECS_PER_SECOND;
+                if (!workerThread->wait(MAX_SCRIPT_QUITTING_TIME)) {
+                    workerThread->terminate();
+                }
+            }
+
+            if (shutdown) {
+                // NOTE: This will be called on the main application thread (among other threads) from stopAllScripts.
+                //       The thread will need to continue to process events, because
+                //       the scripts will likely need to marshall messages across to the main thread, e.g.
+                //       if they access Settings or Menu in any of their shutdown code. So:
+                // Process events for this thread, allowing invokeMethod calls to pass between threads.
+                QCoreApplication::processEvents();
+            }
+
+            // Avoid a pure busy wait
+            QThread::yieldCurrentThread();
+        }
+#endif
+
+        scriptInfoMessage("Script Engine has stopped:" + getFilename());
+    }
+}
+
+QString ScriptManager::getFilename() const {
+    QStringList fileNameParts = _fileNameString.split("/");
+    QString lastPart;
+    if (!fileNameParts.isEmpty()) {
+        lastPart = fileNameParts.last();
+    }
+    return lastPart;
+}
+
+bool ScriptManager::hasValidScriptSuffix(const QString& scriptFileName) {
+    QFileInfo fileInfo(scriptFileName);
+    QString scriptSuffixToLower = fileInfo.completeSuffix().toLower();
+    return scriptSuffixToLower.contains(QString("js"), Qt::CaseInsensitive);
+}
+
+void ScriptManager::loadURL(const QUrl& scriptURL, bool reload) {
+    if (_isRunning) {
+        return;
+    }
+
+    QUrl url = expandScriptUrl(scriptURL);
+    _fileNameString = url.toString();
+    _isReloading = reload;
+
+    // Check that script has a supported file extension
+    if (!hasValidScriptSuffix(_fileNameString)) {
+        scriptErrorMessage("File extension of file: " + _fileNameString + " is not a currently supported script type");
+        emit errorLoadingScript(_fileNameString);
+        return;
+    }
+
+    const auto maxRetries = 0; // for consistency with previous scriptCache->getScript() behavior
+    auto scriptCache = DependencyManager::get<ScriptCache>();
+    scriptCache->getScriptContents(url.toString(), [this](const QString& url, const QString& scriptContents, bool isURL, bool success, const QString&status) {
+        qCDebug(scriptengine) << "loadURL" << url << status << QThread::currentThread();
+        if (!success) {
+            scriptErrorMessage("ERROR Loading file (" + status + "):" + url);
+            emit errorLoadingScript(_fileNameString);
+            return;
+        }
+
+        _scriptContents = scriptContents;
+
+        emit scriptLoaded(url);
+    }, reload, maxRetries);
+}
+
+void ScriptManager::scriptErrorMessage(const QString& message) {
+    qCCritical(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
+    emit errorMessage(message, getFilename());
+}
+
+void ScriptManager::scriptWarningMessage(const QString& message) {
+    qCWarning(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
+    emit warningMessage(message, getFilename());
+}
+
+void ScriptManager::scriptInfoMessage(const QString& message) {
+    qCInfo(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
+    emit infoMessage(message, getFilename());
+}
+
+void ScriptManager::scriptPrintedMessage(const QString& message) {
+    qCDebug(scriptengine, "[%s] %s", qUtf8Printable(getFilename()), qUtf8Printable(message));
+    emit printedMessage(message, getFilename());
+}
+
+void ScriptManager::clearDebugLogWindow() {
+    emit clearDebugWindow();
+}
+
+// Templated qScriptRegisterMetaType fails to compile with raw pointers
+using ScriptableResourceRawPtr = ScriptableResource*;
+
+static ScriptValue scriptableResourceToScriptValue(ScriptEngine* engine,
+                                                    const ScriptableResourceRawPtr& resource) {
+    if (!resource) {
+        return ScriptValue();  // probably shutting down
+    }
+
+    // The first script to encounter this resource will track its memory.
+    // In this way, it will be more likely to GC.
+    // This fails in the case that the resource is used across many scripts, but
+    // in that case it would be too difficult to tell which one should track the memory, and
+    // this serves the common case (use in a single script).
+    auto data = resource->getResource();
+    auto manager = engine->manager();
+    if (data && manager && !resource->isInScript()) {
+        resource->setInScript(true);
+        QObject::connect(data.data(), &Resource::updateSize, manager, &ScriptManager::updateMemoryCost);
+    }
+
+    auto object = engine->newQObject(const_cast<ScriptableResourceRawPtr>(resource), ScriptEngine::ScriptOwnership);
+    return object;
+}
+
+static bool scriptableResourceFromScriptValue(const ScriptValue& value, ScriptableResourceRawPtr& resource) {
+    resource = static_cast<ScriptableResourceRawPtr>(value.toQObject());
+    return true;
+}
+
+/*@jsdoc
+ * The <code>Resource</code> API provides values that define the possible loading states of a resource.
+ *
+ * @namespace Resource
+ *
+ * @hifi-interface
+ * @hifi-client-entity
+ * @hifi-avatar
+ * @hifi-server-entity
+ * @hifi-assignment-client
+ *
+ * @property {Resource.State} State - The possible loading states of a resource. <em>Read-only.</em>
+ */
+static ScriptValue createScriptableResourcePrototype(ScriptManagerPointer manager) {
+    auto engine = manager->engine();
+    auto prototype = engine->newObject();
+
+    // Expose enum State to JS/QML via properties
+    QObject* state = new QObject(manager.get());
+    state->setObjectName("ResourceState");
+    auto metaEnum = QMetaEnum::fromType<ScriptableResource::State>();
+    for (int i = 0; i < metaEnum.keyCount(); ++i) {
+        state->setProperty(metaEnum.key(i), metaEnum.value(i));
+    }
+
+    auto prototypeState = engine->newQObject(state, ScriptEngine::QtOwnership,
+       ScriptEngine::ExcludeSlots | ScriptEngine::ExcludeSuperClassMethods);
+    prototype.setProperty("State", prototypeState);
+
+    return prototype;
+}
+
+ScriptValue externalResourceBucketToScriptValue(ScriptEngine* engine, ExternalResource::Bucket const& in) {
+    return engine->newValue((int)in);
+}
+
+bool externalResourceBucketFromScriptValue(const ScriptValue& object, ExternalResource::Bucket& out) {
+    out = static_cast<ExternalResource::Bucket>(object.toInt32());
+    return true;
+}
+
+void ScriptManager::resetModuleCache(bool deleteScriptCache) {
+    if (QThread::currentThread() != thread()) {
+        executeOnScriptThread([=]() { resetModuleCache(deleteScriptCache); });
+        return;
+    }
+    auto jsRequire = _engine->globalObject().property("Script").property("require");
+    auto cache = jsRequire.property("cache");
+    auto cacheMeta = jsRequire.data();
+
+    if (deleteScriptCache) {
+        auto it = cache.newIterator();
+        while (it->hasNext()) {
+            it->next();
+            if (it->flags() & ScriptValue::SkipInEnumeration) {
+                continue;
+            }
+            qCDebug(scriptengine) << "resetModuleCache(true) -- staging " << it->name() << " for cache reset at next require";
+            cacheMeta.setProperty(it->name(), true);
+        }
+    }
+    cache = _engine->newObject();
+    if (!cacheMeta.isObject()) {
+        cacheMeta = _engine->newObject();
+        cacheMeta.setProperty("id", "Script.require.cacheMeta");
+        cacheMeta.setProperty("type", "cacheMeta");
+        jsRequire.setData(cacheMeta);
+    }
+    cache.setProperty("__created__", (double)QDateTime::currentMSecsSinceEpoch(), ScriptValue::SkipInEnumeration);
+#if DEBUG_JS_MODULES
+    cache.setProperty("__meta__", cacheMeta, READONLY_HIDDEN_PROP_FLAGS);
+#endif
+    jsRequire.setProperty("cache", cache, READONLY_PROP_FLAGS);
+}
+
+void ScriptManager::init() {
+    if (_isInitialized) {
+        return; // only initialize once
+    }
+
+    _isInitialized = true;
+    runStaticInitializers(this);
+
+    auto scriptEngine = _engine.get();
+
+    // register various meta-types
+    registerMIDIMetaTypes(scriptEngine);
+    registerEventTypes(scriptEngine);
+    registerMenuItemProperties(scriptEngine);
+
+    scriptRegisterSequenceMetaType<QVector<QUuid>>(scriptEngine);
+    scriptRegisterSequenceMetaType<QVector<EntityItemID>>(scriptEngine);
+
+    scriptRegisterSequenceMetaType<QVector<glm::vec2>>(scriptEngine);
+    scriptRegisterSequenceMetaType<QVector<glm::quat>>(scriptEngine);
+    scriptRegisterSequenceMetaType<QVector<QString>>(scriptEngine);
+
+    ScriptValue xmlHttpRequestConstructorValue = scriptEngine->newFunction(XMLHttpRequestClass::constructor);
+    scriptEngine->globalObject().setProperty("XMLHttpRequest", xmlHttpRequestConstructorValue);
+
+    ScriptValue webSocketConstructorValue = scriptEngine->newFunction(WebSocketClass::constructor);
+    scriptEngine->globalObject().setProperty("WebSocket", webSocketConstructorValue);
+
+    /*@jsdoc
+     * Prints a message to the program log and emits {@link Script.printedMessage}.
+     * The message logged is the message values separated by spaces.
+     * <p>Alternatively, you can use {@link Script.print} or one of the {@link console} API methods.</p>
+     * @function print
+     * @param {...*} [message] - The message values to print.
+     */
+    scriptEngine->globalObject().setProperty("print", scriptEngine->newFunction(debugPrint));
+
+    scriptRegisterMetaType(scriptEngine, animationDetailsToScriptValue, animationDetailsFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, webSocketToScriptValue, webSocketFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, qWSCloseCodeToScriptValue, qWSCloseCodeFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, wscReadyStateToScriptValue, wscReadyStateFromScriptValue);
+
+    // NOTE: You do not want to end up creating new instances of singletons here. They will be on the ScriptManager thread
+    // and are likely to be unusable if we "reset" the ScriptManager by creating a new one (on a whole new thread).
+
+    scriptEngine->registerGlobalObject("Script", this);
+
+    {
+        // set up Script.require.resolve and Script.require.cache
+        auto Script = scriptEngine->globalObject().property("Script");
+        auto require = Script.property("require");
+        auto resolve = Script.property("_requireResolve");
+        require.setProperty("resolve", resolve, READONLY_PROP_FLAGS);
+        resetModuleCache();
+    }
+
+    scriptRegisterMetaType(scriptEngine, externalResourceBucketToScriptValue, externalResourceBucketFromScriptValue);
+    scriptEngine->registerEnum("Script.ExternalPaths", QMetaEnum::fromType<ExternalResource::Bucket>());
+
+    scriptEngine->registerGlobalObject("Quat", &_quatLibrary);
+    scriptEngine->registerGlobalObject("Vec3", &_vec3Library);
+    scriptEngine->registerGlobalObject("Mat4", &_mat4Library);
+    scriptEngine->registerGlobalObject("Uuid", &_uuidLibrary);
+    scriptEngine->registerGlobalObject("Messages", DependencyManager::get<MessagesClient>().data());
+    scriptEngine->registerGlobalObject("File", new FileScriptingInterface(this));
+    scriptEngine->registerGlobalObject("console", &_consoleScriptingInterface);
+    scriptEngine->registerFunction("console", "info", ConsoleScriptingInterface::info, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "log", ConsoleScriptingInterface::log, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "debug", ConsoleScriptingInterface::debug, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "warn", ConsoleScriptingInterface::warn, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "error", ConsoleScriptingInterface::error, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "exception", ConsoleScriptingInterface::exception, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "assert", ConsoleScriptingInterface::assertion, scriptEngine->currentContext()->argumentCount());
+    scriptEngine->registerFunction("console", "group", ConsoleScriptingInterface::group, 1);
+    scriptEngine->registerFunction("console", "groupCollapsed", ConsoleScriptingInterface::groupCollapsed, 1);
+    scriptEngine->registerFunction("console", "groupEnd", ConsoleScriptingInterface::groupEnd, 0);
+
+    // Scriptable cache access
+    auto resourcePrototype = createScriptableResourcePrototype(shared_from_this());
+    scriptEngine->globalObject().setProperty("Resource", resourcePrototype);
+    scriptEngine->setDefaultPrototype(qMetaTypeId<ScriptableResource*>(), resourcePrototype);
+    scriptRegisterMetaType(scriptEngine, scriptableResourceToScriptValue, scriptableResourceFromScriptValue);
+
+    // constants
+    scriptEngine->globalObject().setProperty("TREE_SCALE", scriptEngine->newValue(TREE_SCALE));
+
+    scriptEngine->registerGlobalObject("Assets", _assetScriptingInterface);
+    scriptEngine->registerGlobalObject("Resources", DependencyManager::get<ResourceScriptingInterface>().data());
+
+    scriptEngine->registerGlobalObject("DebugDraw", &DebugDraw::getInstance());
+
+    scriptRegisterMetaType(scriptEngine, meshToScriptValue, meshFromScriptValue);
+    scriptRegisterMetaType(scriptEngine, meshesToScriptValue, meshesFromScriptValue);
+
+    scriptEngine->registerGlobalObject("UserActivityLogger", DependencyManager::get<UserActivityLoggerScriptingInterface>().data());
+
+#if DEV_BUILD || PR_BUILD
+    scriptEngine->registerGlobalObject("StackTest", new StackTestScriptingInterface(this));
+#endif
+
+}
+
+// registers a global object by name
+void ScriptManager::registerValue(const QString& valueName, ScriptValue value) {
+    _engine->globalObject().setProperty(valueName, value);
+}
+
+// Unregister the handlers for this eventName and entityID.
+void ScriptManager::removeEventHandler(const EntityItemID& entityID, const QString& eventName, const ScriptValue& handler) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::removeEventHandler() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+            "entityID:" << entityID << " eventName:" << eventName;
+#endif
+        QMetaObject::invokeMethod(this, "removeEventHandler",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, eventName),
+                                  Q_ARG(const ScriptValue&, handler));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::removeEventHandler() called on thread [" << QThread::currentThread() << "] entityID:" << entityID << " eventName : " << eventName;
+#endif
+
+    if (!_registeredHandlers.contains(entityID)) {
+        return;
+    }
+    RegisteredEventHandlers& handlersOnEntity = _registeredHandlers[entityID];
+    CallbackList& handlersForEvent = handlersOnEntity[eventName];
+    // ScriptValue does not have operator==(), so we can't use QList::removeOne and friends. So iterate.
+    for (int i = 0; i < handlersForEvent.count(); ++i) {
+        if (handlersForEvent[i].function.equals(handler)) {
+            handlersForEvent.removeAt(i);
+            return; // Design choice: since comparison is relatively expensive, just remove the first matching handler.
+        }
+    }
+}
+
+// Unregister all event handlers for the specified entityID (i.e. the entity is being removed)
+void ScriptManager::removeAllEventHandlers(const EntityItemID& entityID) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::removeAllEventHandlers() called on wrong thread [" << QThread::currentThread() << ", correct thread is " << thread() << " ], ignoring "
+            "entityID:" << entityID;
+#endif
+        return;
+    }
+
+    if (_registeredHandlers.contains(entityID)) {
+        _registeredHandlers.remove(entityID);
+    }
+}
+
+// Register the handler.
+void ScriptManager::addEventHandler(const EntityItemID& entityID, const QString& eventName, const ScriptValue& handler) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::addEventHandler() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+        "entityID:" << entityID << " eventName:" << eventName;
+#endif
+
+        QMetaObject::invokeMethod(this, "addEventHandler",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, eventName),
+                                  Q_ARG(const ScriptValue&, handler));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::addEventHandler() called on thread [" << QThread::currentThread() << "] entityID:" << entityID << " eventName : " << eventName;
+#endif
+
+    if (_registeredHandlers.count() == 0) {
+        // First time any per-entity handler has been added in this script...
+        emit attachDefaultEventHandlers();
+    }
+    if (!_registeredHandlers.contains(entityID)) {
+        _registeredHandlers[entityID] = RegisteredEventHandlers();
+    }
+    CallbackList& handlersForEvent = _registeredHandlers[entityID][eventName];
+    CallbackData handlerData = { handler, currentEntityIdentifier, currentSandboxURL };
+    handlersForEvent << handlerData; // Note that the same handler can be added many times. See removeEntityEventHandler().
+}
+
+bool ScriptManager::isStopped() const {
+    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
+    return !scriptEngines || scriptEngines->isStopped();
+}
+
+void ScriptManager::run() {
+    if (QThread::currentThread() != qApp->thread() && _context == Context::CLIENT_SCRIPT) {
+        // Flag that we're allowed to access local HTML files on UI created from C++ calls on this thread
+        // (because we're a client script)
+        hifi::scripting::setLocalAccessSafeThread(true);
+    }
+
+    auto filenameParts = _fileNameString.split("/");
+    auto name = filenameParts.size() > 0 ? filenameParts[filenameParts.size() - 1] : "unknown";
+    PROFILE_SET_THREAD_NAME("Script: " + name);
+
+    if (isStopped()) {
+        return; // bail early - avoid setting state in init(), as evaluate() will bail too
+    }
+
+    scriptInfoMessage("Script Engine starting:" + getFilename());
+
+    if (!_isInitialized) {
+        init();
+    }
+
+    _isRunning = true;
+    emit runningStateChanged();
+
+    {
+        PROFILE_RANGE(script, _fileNameString);
+        _engine->evaluate(_scriptContents, _fileNameString);
+        _engine->maybeEmitUncaughtException(__FUNCTION__);
+    }
+#ifdef _WIN32
+    // VS13 does not sleep_until unless it uses the system_clock, see:
+    // https://www.reddit.com/r/cpp_questions/comments/3o71ic/sleep_until_not_working_with_a_time_pointsteady/
+    using clock = std::chrono::system_clock;
+#else
+    using clock = std::chrono::high_resolution_clock;
+#endif
+
+    clock::time_point startTime = clock::now();
+    int thisFrame = 0;
+
+    _lastUpdate = usecTimestampNow();
+
+    std::chrono::microseconds totalUpdates(0);
+
+    // TODO: Integrate this with signals/slots instead of reimplementing throttling for ScriptManager
+    while (!_isFinished) {
+        auto beforeSleep = clock::now();
+
+        // Throttle to SCRIPT_FPS
+        // We'd like to try to keep the script at a solid SCRIPT_FPS update rate. And so we will
+        // calculate a sleepUntil to be the time from our start time until the original target
+        // sleepUntil for this frame. This approach will allow us to "catch up" in the event
+        // that some of our script udpates/frames take a little bit longer than the target average
+        // to execute.
+        // NOTE: if we go to variable SCRIPT_FPS, then we will need to reconsider this approach
+        const std::chrono::microseconds TARGET_SCRIPT_FRAME_DURATION(USECS_PER_SECOND / SCRIPT_FPS + 1);
+        clock::time_point targetSleepUntil(startTime + (thisFrame++ * TARGET_SCRIPT_FRAME_DURATION));
+
+        // However, if our sleepUntil is not at least our average update and timer execution time
+        // into the future it means our script is taking too long in its updates, and we want to
+        // punish the script a little bit. So we will force the sleepUntil to be at least our
+        // averageUpdate + averageTimerPerFrame time into the future.
+        auto averageUpdate = totalUpdates / thisFrame;
+        auto averageTimerPerFrame = _totalTimerExecution / thisFrame;
+        auto averageTimerAndUpdate = averageUpdate + averageTimerPerFrame;
+        auto sleepUntil = std::max(targetSleepUntil, beforeSleep + averageTimerAndUpdate);
+
+        // We don't want to actually sleep for too long, because it causes our scripts to hang
+        // on shutdown and stop... so we want to loop and sleep until we've spent our time in
+        // purgatory, constantly checking to see if our script was asked to end
+        bool processedEvents = false;
+        if (!_isFinished) {
+            PROFILE_RANGE(script, "processEvents-sleep");
+            std::chrono::milliseconds sleepFor =
+                std::chrono::duration_cast<std::chrono::milliseconds>(sleepUntil - clock::now());
+            if (sleepFor > std::chrono::milliseconds(0)) {
+                QEventLoop loop;
+                QTimer timer;
+                timer.setSingleShot(true);
+                connect(&timer, &QTimer::timeout, &loop, &QEventLoop::quit);
+                timer.start(sleepFor.count());
+                loop.exec();
+            } else {
+                QCoreApplication::processEvents();
+            }
+            processedEvents = true;
+        }
+
+        PROFILE_RANGE(script, "ScriptMainLoop");
+
+#ifdef SCRIPT_DELAY_DEBUG
+        {
+            auto actuallySleptUntil = clock::now();
+            uint64_t seconds = std::chrono::duration_cast<std::chrono::seconds>(actuallySleptUntil - startTime).count();
+            if (seconds > 0) { // avoid division by zero and time travel
+                uint64_t fps = thisFrame / seconds;
+                // Overreporting artificially reduces the reported rate
+                if (thisFrame % SCRIPT_FPS == 0) {
+                    qCDebug(scriptengine) <<
+                        "Frame:" << thisFrame <<
+                        "Slept (us):" << std::chrono::duration_cast<std::chrono::microseconds>(actuallySleptUntil - beforeSleep).count() <<
+                        "Avg Updates (us):" << averageUpdate.count() <<
+                        "FPS:" << fps;
+                }
+            }
+        }
+#endif
+        if (_isFinished) {
+            break;
+        }
+
+        // Only call this if we didn't processEvents as part of waiting for next frame
+        if (!processedEvents) {
+            PROFILE_RANGE(script, "processEvents");
+            QCoreApplication::processEvents();
+        }
+
+        if (_isFinished) {
+            break;
+        }
+
+        if (!_isFinished) {
+            emit releaseEntityPacketSenderMessages(false);
+        }
+
+        qint64 now = usecTimestampNow();
+
+        // we check for 'now' in the past in case people set their clock back
+        if (_emitScriptUpdates() && _lastUpdate < now) {
+            float deltaTime = (float) (now - _lastUpdate) / (float) USECS_PER_SECOND;
+            if (!_isFinished) {
+                auto preUpdate = clock::now();
+                {
+                    PROFILE_RANGE(script, "ScriptUpdate");
+                    emit update(deltaTime);
+                }
+                auto postUpdate = clock::now();
+                auto elapsed = (postUpdate - preUpdate);
+                totalUpdates += std::chrono::duration_cast<std::chrono::microseconds>(elapsed);
+            }
+        }
+        _lastUpdate = now;
+
+        // only clear exceptions if we are not in the middle of evaluating
+        if (!_engine->isEvaluating() && _engine->hasUncaughtException()) {
+            qCWarning(scriptengine) << __FUNCTION__ << "---------- UNCAUGHT EXCEPTION --------";
+            qCWarning(scriptengine) << "runInThread" << _engine->uncaughtException().toString();
+            emit unhandledException(_engine->cloneUncaughtException(__FUNCTION__));
+            _engine->clearExceptions();
+        }
+    }
+    scriptInfoMessage("Script Engine stopping:" + getFilename());
+
+    stopAllTimers(); // make sure all our timers are stopped if the script is ending
+    emit scriptEnding();
+
+    emit releaseEntityPacketSenderMessages(true);
+
+    emit finished(_fileNameString, shared_from_this());
+
+    // Don't leave our local-file-access flag laying around, reset it to false when the scriptengine 
+    // thread is finished
+    hifi::scripting::setLocalAccessSafeThread(false);
+    _isRunning = false;
+    emit runningStateChanged();
+    emit doneRunning();
+}
+
+// NOTE: This is private because it must be called on the same thread that created the timers, which is why
+// we want to only call it in our own run "shutdown" processing.
+void ScriptManager::stopAllTimers() {
+    QMutableHashIterator<QTimer*, CallbackData> i(_timerFunctionMap);
+    int j {0};
+    while (i.hasNext()) {
+        i.next();
+        QTimer* timer = i.key();
+        qCDebug(scriptengine) << getFilename() << "stopAllTimers[" << j++ << "]";
+        stopTimer(timer);
+    }
+}
+
+void ScriptManager::stopAllTimersForEntityScript(const EntityItemID& entityID) {
+     // We could maintain a separate map of entityID => QTimer, but someone will have to prove to me that it's worth the complexity. -HRS
+    QVector<QTimer*> toDelete;
+    QMutableHashIterator<QTimer*, CallbackData> i(_timerFunctionMap);
+    while (i.hasNext()) {
+        i.next();
+        if (i.value().definingEntityIdentifier != entityID) {
+            continue;
+        }
+        QTimer* timer = i.key();
+        toDelete << timer; // don't delete while we're iterating. save it.
+    }
+    for (auto timer:toDelete) { // now reap 'em
+        stopTimer(timer);
+    }
+
+}
+
+void ScriptManager::stop(bool marshal) {
+    _isStopping = true; // this can be done on any thread
+
+    if (marshal) {
+        QMetaObject::invokeMethod(this, "stop");
+        return;
+    }
+    if (!_isFinished) {
+        _isFinished = true;
+        emit runningStateChanged();
+    }
+}
+
+void ScriptManager::updateMemoryCost(const qint64& deltaSize) {
+    _engine->updateMemoryCost(deltaSize);
+}
+
+void ScriptManager::timerFired() {
+    if (isStopped()) {
+        scriptWarningMessage("Script.timerFired() while shutting down is ignored... parent script:" + getFilename());
+        return; // bail early
+    }
+
+    QTimer* callingTimer = reinterpret_cast<QTimer*>(sender());
+    CallbackData timerData = _timerFunctionMap.value(callingTimer);
+
+    if (!callingTimer->isActive()) {
+        // this timer is done, we can kill it
+        _timerFunctionMap.remove(callingTimer);
+        delete callingTimer;
+    }
+
+    // call the associated JS function, if it exists
+    if (timerData.function.isValid()) {
+        PROFILE_RANGE(script, __FUNCTION__);
+        auto preTimer = p_high_resolution_clock::now();
+        callWithEnvironment(timerData.definingEntityIdentifier, timerData.definingSandboxURL, timerData.function, timerData.function, ScriptValueList());
+        auto postTimer = p_high_resolution_clock::now();
+        auto elapsed = (postTimer - preTimer);
+        _totalTimerExecution += std::chrono::duration_cast<std::chrono::microseconds>(elapsed);
+    } else {
+        qCWarning(scriptengine) << "timerFired -- invalid function" << timerData.function.toVariant().toString();
+    }
+}
+
+QTimer* ScriptManager::setupTimerWithInterval(const ScriptValue& function, int intervalMS, bool isSingleShot) {
+    // create the timer, add it to the map, and start it
+    QTimer* newTimer = new QTimer(this);
+    newTimer->setSingleShot(isSingleShot);
+
+    // The default timer type is not very accurate below about 200ms http://doc.qt.io/qt-5/qt.html#TimerType-enum
+    static const int MIN_TIMEOUT_FOR_COARSE_TIMER = 200;
+    if (intervalMS < MIN_TIMEOUT_FOR_COARSE_TIMER) {
+        newTimer->setTimerType(Qt::PreciseTimer);
+    }
+
+    connect(newTimer, &QTimer::timeout, this, &ScriptManager::timerFired);
+
+    // make sure the timer stops when the script does
+    connect(this, &ScriptManager::scriptEnding, newTimer, &QTimer::stop);
+
+
+    CallbackData timerData = { function, currentEntityIdentifier, currentSandboxURL };
+    _timerFunctionMap.insert(newTimer, timerData);
+
+    newTimer->start(intervalMS);
+    return newTimer;
+}
+
+QTimer* ScriptManager::setInterval(const ScriptValue& function, int intervalMS) {
+    if (isStopped()) {
+        scriptWarningMessage("Script.setInterval() while shutting down is ignored... parent script:" + getFilename());
+        return NULL; // bail early
+    }
+
+    return setupTimerWithInterval(function, intervalMS, false);
+}
+
+QTimer* ScriptManager::setTimeout(const ScriptValue& function, int timeoutMS) {
+    if (isStopped()) {
+        scriptWarningMessage("Script.setTimeout() while shutting down is ignored... parent script:" + getFilename());
+        return NULL; // bail early
+    }
+
+    return setupTimerWithInterval(function, timeoutMS, true);
+}
+
+void ScriptManager::stopTimer(QTimer *timer) {
+    if (_timerFunctionMap.contains(timer)) {
+        timer->stop();
+        _timerFunctionMap.remove(timer);
+        delete timer;
+    } else {
+        qCDebug(scriptengine) << "stopTimer -- not in _timerFunctionMap" << timer;
+    }
+}
+
+QUrl ScriptManager::resolvePath(const QString& include) const {
+    QUrl url(include);
+    // first lets check to see if it's already a full URL -- or a Windows path like "c:/"
+    if (include.startsWith("/") || url.scheme().length() == 1) {
+        url = QUrl::fromLocalFile(include);
+    }
+    if (!url.isRelative()) {
+        return expandScriptUrl(url);
+    }
+
+    // we apparently weren't a fully qualified url, so, let's assume we're relative
+    // to the first absolute URL in the JS scope chain
+    QUrl parentURL;
+    auto context = _engine->currentContext();
+    ScriptContextPointer parentContext;  // using this variable to maintain parent variable lifespan
+    do {
+        auto contextInfo = context->functionContext();
+        parentURL = QUrl(contextInfo->fileName());
+        parentContext = context->parentContext();
+        context = parentContext.get();
+    } while (parentURL.isRelative() && context);
+
+    if (parentURL.isRelative()) {
+        // fallback to the "include" parent (if defined, this will already be absolute)
+        parentURL = QUrl(_parentURL);
+    }
+
+    if (parentURL.isRelative()) {
+        // fallback to the original script engine URL
+        parentURL = QUrl(_fileNameString);
+
+        // if still relative and path-like, then this is probably a local file...
+        if (parentURL.isRelative() && url.path().contains("/")) {
+            parentURL = QUrl::fromLocalFile(_fileNameString);
+        }
+    }
+
+    // at this point we should have a legitimate fully qualified URL for our parent
+    url = expandScriptUrl(parentURL.resolved(url));
+    return url;
+}
+
+QUrl ScriptManager::resourcesPath() const {
+    return QUrl(PathUtils::resourcesUrl());
+}
+
+void ScriptManager::print(const QString& message) {
+    emit printedMessage(message, getFilename());
+}
+
+
+void ScriptManager::beginProfileRange(const QString& label) const {
+    PROFILE_SYNC_BEGIN(script, label.toStdString().c_str(), label.toStdString().c_str());
+}
+
+void ScriptManager::endProfileRange(const QString& label) const {
+    PROFILE_SYNC_END(script, label.toStdString().c_str(), label.toStdString().c_str());
+}
+
+// Script.require.resolve -- like resolvePath, but performs more validation and throws exceptions on invalid module identifiers (for consistency with Node.js)
+QString ScriptManager::_requireResolve(const QString& moduleId, const QString& relativeTo) {
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return QString();
+    }
+    QUrl defaultScriptsLoc = PathUtils::defaultScriptsLocation();
+    QUrl url(moduleId);
+
+    auto displayId = moduleId;
+    if (displayId.length() > MAX_DEBUG_VALUE_LENGTH) {
+        displayId = displayId.mid(0, MAX_DEBUG_VALUE_LENGTH) + "...";
+    }
+    auto message = QString("Cannot find module '%1' (%2)").arg(displayId);
+
+    auto throwResolveError = [&](const ScriptValue& error) -> QString {
+        _engine->raiseException(error);
+        _engine->maybeEmitUncaughtException("require.resolve");
+        return QString();
+    };
+
+    // de-fuzz the input a little by restricting to rational sizes
+    auto idLength = url.toString().length();
+    if (idLength < 1 || idLength > MAX_MODULE_ID_LENGTH) {
+        auto details = QString("rejecting invalid module id size (%1 chars [1,%2])")
+            .arg(idLength).arg(MAX_MODULE_ID_LENGTH);
+        return throwResolveError(_engine->makeError(_engine->newValue(message.arg(details)), "RangeError"));
+    }
+
+    // this regex matches: absolute, dotted or path-like URLs
+    // (ie: the kind of stuff ScriptManager::resolvePath already handles)
+    QRegularExpression qualified ("^\\w+:|^/|^[.]{1,2}(/|$)");
+
+    // this is for module.require (which is a bound version of require that's always relative to the module path)
+    if (!relativeTo.isEmpty()) {
+        url = QUrl(relativeTo).resolved(moduleId);
+        url = resolvePath(url.toString());
+    } else if (qualified.match(moduleId).hasMatch()) {
+        url = resolvePath(moduleId);
+    } else {
+        // check if the moduleId refers to a "system" module
+        QString systemPath = defaultScriptsLoc.path();
+        QString systemModulePath = QString("%1/modules/%2.js").arg(systemPath).arg(moduleId);
+        url = defaultScriptsLoc;
+        url.setPath(systemModulePath);
+        if (!QFileInfo(url.toLocalFile()).isFile()) {
+            if (!moduleId.contains("./")) {
+                // the user might be trying to refer to a relative file without anchoring it
+                // let's do them a favor and test for that case -- offering specific advice if detected
+                auto unanchoredUrl = resolvePath("./" + moduleId);
+                if (QFileInfo(unanchoredUrl.toLocalFile()).isFile()) {
+                    auto msg = QString("relative module ids must be anchored; use './%1' instead")
+                        .arg(moduleId);
+                    return throwResolveError(_engine->makeError(_engine->newValue(message.arg(msg))));
+                }
+            }
+            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("system module not found"))));
+        }
+    }
+
+    if (url.isRelative()) {
+        return throwResolveError(_engine->makeError(_engine->newValue(message.arg("could not resolve module id"))));
+    }
+
+    // if it looks like a local file, verify that it's an allowed path and really a file
+    if (url.isLocalFile()) {
+        QFileInfo file(url.toLocalFile());
+        QUrl canonical = url;
+        if (file.exists()) {
+            canonical.setPath(file.canonicalFilePath());
+        }
+
+        bool disallowOutsideFiles = !PathUtils::defaultScriptsLocation().isParentOf(canonical) && !currentSandboxURL.isLocalFile();
+        if (disallowOutsideFiles && !PathUtils::isDescendantOf(canonical, currentSandboxURL)) {
+            return throwResolveError(_engine->makeError(_engine->newValue(message.arg(
+                QString("path '%1' outside of origin script '%2' '%3'")
+                    .arg(PathUtils::stripFilename(url))
+                    .arg(PathUtils::stripFilename(currentSandboxURL))
+                    .arg(canonical.toString())
+            ))));
+        }
+        if (!file.exists()) {
+            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("path does not exist: " + url.toLocalFile()))));
+        }
+        if (!file.isFile()) {
+            return throwResolveError(_engine->makeError(_engine->newValue(message.arg("path is not a file: " + url.toLocalFile()))));
+        }
+    }
+
+    _engine->maybeEmitUncaughtException(__FUNCTION__);
+    return url.toString();
+}
+
+// retrieves the current parent module from the JS scope chain
+ScriptValue ScriptManager::currentModule() {
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return _engine->nullValue();
+    }
+    auto jsRequire = _engine->globalObject().property("Script").property("require");
+    auto cache = jsRequire.property("cache");
+    ScriptValue candidate;
+    ScriptContextPointer parentContext;  // using this variable to maintain parent variable lifespan
+    for (auto context = _engine->currentContext(); context && !candidate.isObject();
+         parentContext = context->parentContext(), context = parentContext.get()) {
+        auto contextInfo = context->functionContext();
+        candidate = cache.property(contextInfo->fileName());
+    }
+    if (!candidate.isObject()) {
+        return ScriptValue();
+    }
+    return candidate;
+}
+
+// replaces or adds "module" to "parent.children[]" array
+// (for consistency with Node.js and userscript cache invalidation without "cache busters")
+bool ScriptManager::registerModuleWithParent(const ScriptValue& module, const ScriptValue& parent) {
+    auto children = parent.property("children");
+    if (children.isArray()) {
+        auto key = module.property("id");
+        auto length = children.property("length").toInt32();
+        for (int i = 0; i < length; i++) {
+            if (children.property(i).property("id").strictlyEquals(key)) {
+                qCDebug(scriptengine_module) << key.toString() << " updating parent.children[" << i << "] = module";
+                children.setProperty(i, module);
+                return true;
+            }
+        }
+        qCDebug(scriptengine_module) << key.toString() << " appending parent.children[" << length << "] = module";
+        children.setProperty(length, module);
+        return true;
+    } else if (parent.isValid()) {
+        qCDebug(scriptengine_module) << "registerModuleWithParent -- unrecognized parent" << parent.toVariant().toString();
+    }
+    return false;
+}
+
+// creates a new JS "module" Object with default metadata properties
+ScriptValue ScriptManager::newModule(const QString& modulePath, const ScriptValue& parent) {
+    auto closure = _engine->newObject();
+    auto exports = _engine->newObject();
+    auto module = _engine->newObject();
+    qCDebug(scriptengine_module) << "newModule" << parent.property("filename").toString();
+
+    closure.setProperty("module", module, READONLY_PROP_FLAGS);
+
+    // note: this becomes the "exports" free variable, so should not be set read only
+    closure.setProperty("exports", exports);
+
+    // make the closure available to module instantiation
+    module.setProperty("__closure__", closure, READONLY_HIDDEN_PROP_FLAGS);
+
+    // for consistency with Node.js Module
+    module.setProperty("id", modulePath, READONLY_PROP_FLAGS);
+    module.setProperty("filename", modulePath, READONLY_PROP_FLAGS);
+    module.setProperty("exports", exports); // not readonly
+    module.setProperty("loaded", false, READONLY_PROP_FLAGS);
+    module.setProperty("parent", parent, READONLY_PROP_FLAGS);
+    module.setProperty("children", _engine->newArray(), READONLY_PROP_FLAGS);
+
+    // module.require is a bound version of require that always resolves relative to that module's path
+    auto boundRequire = _engine->evaluate("(function(id) { return Script.require(Script.require.resolve(id, this.filename)); })", "(boundRequire)");
+    module.setProperty("require", boundRequire, READONLY_PROP_FLAGS);
+
+    return module;
+}
+
+// synchronously fetch a module's source code using BatchLoader
+QVariantMap ScriptManager::fetchModuleSource(const QString& modulePath, const bool forceDownload) {
+    using UrlMap = QMap<QUrl, QString>;
+    auto scriptCache = DependencyManager::get<ScriptCache>();
+    QVariantMap req;
+    qCDebug(scriptengine_module) << "require.fetchModuleSource: " << QUrl(modulePath).fileName() << QThread::currentThread();
+
+    auto onload = [=, &req](const UrlMap& data, const UrlMap& _status) {
+        auto url = modulePath;
+        auto status = _status[url];
+        auto contents = data[url];
+        if (isStopping()) {
+            req["status"] = "Stopped";
+            req["success"] = false;
+        } else {
+            req["url"] = url;
+            req["status"] = status;
+            req["success"] = ScriptCache::isSuccessStatus(status);
+            req["contents"] = contents;
+        }
+    };
+
+    if (forceDownload) {
+        qCDebug(scriptengine_module) << "require.requestScript -- clearing cache for" << modulePath;
+        scriptCache->deleteScript(modulePath);
+    }
+    BatchLoader* loader = new BatchLoader(QList<QUrl>({ modulePath }));
+    connect(loader, &BatchLoader::finished, this, onload);
+    connect(this, &QObject::destroyed, loader, &QObject::deleteLater);
+    // fail faster? (since require() blocks the engine thread while resolving dependencies)
+    const int MAX_RETRIES = 1;
+
+    loader->start(MAX_RETRIES);
+
+    if (!loader->isFinished()) {
+        // This lambda can get called AFTER this local scope has completed.
+        // This is why we pass smart ptrs to the lambda instead of references to local variables.
+        auto monitor = std::make_shared<QTimer>();
+        auto loop = std::make_shared<QEventLoop>();
+        QObject::connect(loader, &BatchLoader::finished, this, [monitor, loop] {
+            monitor->stop();
+            loop->quit();
+        });
+
+        // this helps detect the case where stop() is invoked during the download
+        //  but not seen in time to abort processing in onload()...
+        connect(monitor.get(), &QTimer::timeout, this, [this, loop] {
+            if (isStopping()) {
+                loop->exit(-1);
+            }
+        });
+        monitor->start(500);
+        loop->exec();
+    }
+    loader->deleteLater();
+    return req;
+}
+
+// evaluate a pending module object using the fetched source code
+ScriptValue ScriptManager::instantiateModule(const ScriptValue& module, const QString& sourceCode) {
+    ScriptValue result;
+    auto modulePath = module.property("filename").toString();
+    auto closure = module.property("__closure__");
+
+    qCDebug(scriptengine_module) << QString("require.instantiateModule: %1 / %2 bytes")
+        .arg(QUrl(modulePath).fileName()).arg(sourceCode.length());
+
+    if (module.property("content-type").toString() == "application/json") {
+        qCDebug(scriptengine_module) << "... parsing as JSON";
+        closure.setProperty("__json", sourceCode);
+        result = _engine->evaluateInClosure(closure, _engine->newProgram( "module.exports = JSON.parse(__json)", modulePath ));
+    } else {
+        // scoped vars for consistency with Node.js
+        closure.setProperty("require", module.property("require"));
+        closure.setProperty("__filename", modulePath, READONLY_HIDDEN_PROP_FLAGS);
+        closure.setProperty("__dirname", QString(modulePath).replace(QRegExp("/[^/]*$"), ""), READONLY_HIDDEN_PROP_FLAGS);
+        result = _engine->evaluateInClosure(closure, _engine->newProgram( sourceCode, modulePath ));
+    }
+    _engine->maybeEmitUncaughtException(__FUNCTION__);
+    return result;
+}
+
+// CommonJS/Node.js like require/module support
+ScriptValue ScriptManager::require(const QString& moduleId) {
+    qCDebug(scriptengine_module) << "ScriptManager::require(" << moduleId.left(MAX_DEBUG_VALUE_LENGTH) << ")";
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return _engine->nullValue();
+    }
+
+    auto jsRequire = _engine->globalObject().property("Script").property("require");
+    auto cacheMeta = jsRequire.data();
+    auto cache = jsRequire.property("cache");
+    auto parent = currentModule();
+
+    auto throwModuleError = [&](const QString& modulePath, const ScriptValue& error) {
+        cache.setProperty(modulePath, _engine->nullValue());
+        if (!error.isNull()) {
+#ifdef DEBUG_JS_MODULES
+            qCWarning(scriptengine_module) << "throwing module error:" << error.toString() << modulePath << error.property("stack").toString();
+#endif
+            _engine->raiseException(error);
+        }
+        _engine->maybeEmitUncaughtException("module");
+        return _engine->nullValue();
+    };
+
+    // start by resolving the moduleId into a fully-qualified path/URL
+    QString modulePath = _requireResolve(moduleId);
+    if (modulePath.isNull() || _engine->hasUncaughtException()) {
+        // the resolver already threw an exception -- bail early
+        _engine->maybeEmitUncaughtException(__FUNCTION__);
+        return _engine->nullValue();
+    }
+
+    // check the resolved path against the cache
+    auto module = cache.property(modulePath);
+
+    // modules get cached in `Script.require.cache` and (similar to Node.js) users can access it
+    // to inspect particular entries and invalidate them by deleting the key:
+    //   `delete Script.require.cache[Script.require.resolve(moduleId)];`
+    
+    // Check to see if we should invalidate the cache based on a user setting.
+    Setting::Handle<bool> getCachebustSetting {"cachebustScriptRequire", false };
+
+    // cacheMeta is just used right now to tell deleted keys apart from undefined ones
+    bool invalidateCache = getCachebustSetting.get() || (module.isUndefined() && cacheMeta.property(moduleId).isValid());
+
+    // reset the cacheMeta record so invalidation won't apply next time, even if the module fails to load
+    cacheMeta.setProperty(modulePath, ScriptValue());
+
+    auto exports = module.property("exports");
+    if (!invalidateCache && exports.isObject()) {
+        // we have found a cached module -- just need to possibly register it with current parent
+        qCDebug(scriptengine_module) << QString("require - using cached module for '%1' (loaded: %2)")
+            .arg(moduleId).arg(module.property("loaded").toString());
+        registerModuleWithParent(module, parent);
+        _engine->maybeEmitUncaughtException("cached module");
+        return exports;
+    }
+
+    // bootstrap / register new empty module
+    module = newModule(modulePath, parent);
+    registerModuleWithParent(module, parent);
+
+    // add it to the cache (this is done early so any cyclic dependencies pick up)
+    cache.setProperty(modulePath, module);
+
+    // download the module source
+    auto req = fetchModuleSource(modulePath, invalidateCache);
+
+    if (!req.contains("success") || !req["success"].toBool()) {
+        auto error = QString("error retrieving script (%1)").arg(req["status"].toString());
+        return throwModuleError(modulePath, _engine->newValue(error));
+    }
+
+#if DEBUG_JS_MODULES
+    qCDebug(scriptengine_module) << "require.loaded: " <<
+        QUrl(req["url"].toString()).fileName() << req["status"].toString();
+#endif
+
+    auto sourceCode = req["contents"].toString();
+
+    if (QUrl(modulePath).fileName().endsWith(".json", Qt::CaseInsensitive)) {
+        module.setProperty("content-type", "application/json");
+    } else {
+        module.setProperty("content-type", "application/javascript");
+    }
+
+    // evaluate the module
+    auto result = instantiateModule(module, sourceCode);
+
+    if (result.isError() && !result.strictlyEquals(module.property("exports"))) {
+        qCWarning(scriptengine_module) << "-- result.isError --" << result.toString();
+        return throwModuleError(modulePath, result);
+    }
+
+    // mark as fully-loaded
+    module.setProperty("loaded", true, READONLY_PROP_FLAGS);
+
+    // set up a new reference point for detecting cache key deletion
+    cacheMeta.setProperty(modulePath, module);
+
+    qCDebug(scriptengine_module) << "//ScriptManager::require(" << moduleId << ")";
+
+    _engine->maybeEmitUncaughtException(__FUNCTION__);
+    return module.property("exports");
+}
+
+// If a callback is specified, the included files will be loaded asynchronously and the callback will be called
+// when all of the files have finished loading.
+// If no callback is specified, the included files will be loaded synchronously and will block execution until
+// all of the files have finished loading.
+void ScriptManager::include(const QStringList& includeFiles, const ScriptValue& callback) {
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return;
+    }
+    if (isStopped()) {
+        scriptWarningMessage("Script.include() while shutting down is ignored... includeFiles:"
+                + includeFiles.join(",") + "parent script:" + getFilename());
+        return; // bail early
+    }
+    QList<QUrl> urls;
+
+    for (QString includeFile : includeFiles) {
+        QString file = DependencyManager::get<ResourceManager>()->normalizeURL(includeFile);
+        QUrl thisURL;
+        bool isStandardLibrary = false;
+        if (file.startsWith("/~/")) {
+            thisURL = expandScriptUrl(QUrl::fromLocalFile(expandScriptPath(file)));
+            QUrl defaultScriptsLoc = PathUtils::defaultScriptsLocation();
+            if (!defaultScriptsLoc.isParentOf(thisURL)) {
+                scriptWarningMessage("Script.include() -- skipping" + file + "-- outside of standard libraries");
+                continue;
+            }
+            isStandardLibrary = true;
+        } else {
+            thisURL = resolvePath(file);
+        }
+
+        bool disallowOutsideFiles = thisURL.isLocalFile() && !isStandardLibrary && !currentSandboxURL.isLocalFile();
+        if (disallowOutsideFiles && !PathUtils::isDescendantOf(thisURL, currentSandboxURL)) {
+            scriptWarningMessage("Script.include() ignoring file path" + thisURL.toString()
+                                + "outside of original entity script" + currentSandboxURL.toString());
+        } else {
+            // We could also check here for CORS, but we don't yet.
+            // It turns out that QUrl.resolve will not change hosts and copy authority, so we don't need to check that here.
+            urls.append(thisURL);
+        }
+    }
+
+    // If there are no URLs left to download, don't bother attempting to download anything and return early
+    if (urls.size() == 0) {
+        return;
+    }
+
+    BatchLoader* loader = new BatchLoader(urls);
+    EntityItemID capturedEntityIdentifier = currentEntityIdentifier;
+    QUrl capturedSandboxURL = currentSandboxURL;
+
+    auto evaluateScripts = [=](const QMap<QUrl, QString>& data, const QMap<QUrl, QString>& status) {
+        auto parentURL = _parentURL;
+        for (QUrl url : urls) {
+            QString contents = data[url];
+            if (contents.isNull()) {
+                scriptErrorMessage("Error loading file (" + status[url] +"): " + url.toString());
+            } else {
+                std::lock_guard<std::recursive_mutex> lock(_lock);
+                if (!_includedURLs.contains(url)) {
+                    _includedURLs << url;
+                    // Set the parent url so that path resolution will be relative
+                    // to this script's url during its initial evaluation
+                    _parentURL = url.toString();
+                    auto operation = [&]() {
+                        _engine->evaluate(contents, url.toString());
+                    };
+
+                    doWithEnvironment(capturedEntityIdentifier, capturedSandboxURL, operation);
+                    if(_engine->hasUncaughtException()) {
+                        emit unhandledException(_engine->cloneUncaughtException("evaluateInclude"));
+                        _engine->clearExceptions();
+                    }
+                } else {
+                    scriptPrintedMessage("Script.include() skipping evaluation of previously included url:" + url.toString());
+                }
+            }
+        }
+        _parentURL = parentURL;
+
+        if (callback.isFunction()) {
+            callWithEnvironment(capturedEntityIdentifier, capturedSandboxURL, callback, ScriptValue(), ScriptValueList());
+        }
+
+        loader->deleteLater();
+    };
+
+    connect(loader, &BatchLoader::finished, this, evaluateScripts);
+
+    // If we are destroyed before the loader completes, make sure to clean it up
+    connect(this, &QObject::destroyed, loader, &QObject::deleteLater);
+
+    loader->start(processLevelMaxRetries);
+
+    if (!callback.isFunction() && !loader->isFinished()) {
+        QEventLoop loop;
+        QObject::connect(loader, &BatchLoader::finished, &loop, &QEventLoop::quit);
+        loop.exec();
+    }
+}
+
+void ScriptManager::include(const QString& includeFile, const ScriptValue& callback) {
+    if (isStopped()) {
+        scriptWarningMessage("Script.include() while shutting down is ignored...  includeFile:"
+                    + includeFile + "parent script:" + getFilename());
+        return; // bail early
+    }
+
+    QStringList urls;
+    urls.append(includeFile);
+    include(urls, callback);
+}
+
+// NOTE: The load() command is similar to the include() command except that it loads the script
+// as a stand-alone script. To accomplish this, the ScriptManager class just emits a signal which
+// the Application or other context will connect to in order to know to actually load the script
+void ScriptManager::load(const QString& loadFile) {
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return;
+    }
+    if (isStopped()) {
+        scriptWarningMessage("Script.load() while shutting down is ignored... loadFile:"
+                + loadFile + "parent script:" + getFilename());
+        return; // bail early
+    }
+    if (!currentEntityIdentifier.isInvalidID()) {
+        scriptWarningMessage("Script.load() from entity script is ignored...  loadFile:"
+                + loadFile + "parent script:" + getFilename() + "entity: " + currentEntityIdentifier.toString());
+        return; // bail early
+    }
+
+    QUrl url = resolvePath(loadFile);
+    if (_isReloading) {
+        auto scriptCache = DependencyManager::get<ScriptCache>();
+        scriptCache->deleteScript(url.toString());
+        emit reloadScript(url.toString(), false);
+    } else {
+        emit loadScript(url.toString(), false);
+    }
+}
+
+// Look up the handler associated with eventName and entityID. If found, evalute the argGenerator thunk and call the handler with those args
+void ScriptManager::forwardHandlerCall(const EntityItemID& entityID, const QString& eventName, const ScriptValueList& eventHandlerArgs) {
+    if (QThread::currentThread() != thread()) {
+        qCDebug(scriptengine) << "*** ERROR *** ScriptManager::forwardHandlerCall() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
+        assert(false);
+        return ;
+    }
+    if (!_registeredHandlers.contains(entityID)) {
+        return;
+    }
+    const RegisteredEventHandlers& handlersOnEntity = _registeredHandlers[entityID];
+    if (!handlersOnEntity.contains(eventName)) {
+        return;
+    }
+    CallbackList handlersForEvent = handlersOnEntity[eventName];
+    if (!handlersForEvent.isEmpty()) {
+        for (int i = 0; i < handlersForEvent.count(); ++i) {
+            // handlersForEvent[i] can contain many handlers that may have each been added by different interface or entity scripts,
+            // and the entity scripts may be for entities other than the one this is a handler for.
+            // Fortunately, the definingEntityIdentifier captured the entity script id (if any) when the handler was added.
+            CallbackData& handler = handlersForEvent[i];
+            callWithEnvironment(handler.definingEntityIdentifier, handler.definingSandboxURL, handler.function, ScriptValue(), eventHandlerArgs);
+        }
+    }
+}
+
+int ScriptManager::getNumRunningEntityScripts() const {
+    QReadLocker locker { &_entityScriptsLock };
+    int sum = 0;
+    for (const auto& st : _entityScripts) {
+        if (st.status == EntityScriptStatus::RUNNING) {
+            ++sum;
+        }
+    }
+    return sum;
+}
+
+void ScriptManager::setEntityScriptDetails(const EntityItemID& entityID, const EntityScriptDetails& details) {
+    {
+        QWriteLocker locker { &_entityScriptsLock };
+        _entityScripts[entityID] = details;
+    }
+    emit entityScriptDetailsUpdated();
+}
+
+void ScriptManager::updateEntityScriptStatus(const EntityItemID& entityID, const EntityScriptStatus &status, const QString& errorInfo) {
+    {
+        QWriteLocker locker { &_entityScriptsLock };
+        EntityScriptDetails& details = _entityScripts[entityID];
+        details.status = status;
+        details.errorInfo = errorInfo;
+    }
+    emit entityScriptDetailsUpdated();
+}
+
+QVariant ScriptManager::cloneEntityScriptDetails(const EntityItemID& entityID) {
+    static const QVariant NULL_VARIANT { qVariantFromValue((QObject*)nullptr) };
+    QVariantMap map;
+    if (entityID.isNull()) {
+        // TODO: find better way to report JS Error across thread/process boundaries
+        map["isError"] = true;
+        map["errorInfo"] = "Error: getEntityScriptDetails -- invalid entityID";
+    } else {
+#ifdef DEBUG_ENTITY_STATES
+        qDebug() << "cloneEntityScriptDetails" << entityID << QThread::currentThread();
+#endif
+        EntityScriptDetails scriptDetails;
+        if (getEntityScriptDetails(entityID, scriptDetails)) {
+#ifdef DEBUG_ENTITY_STATES
+            qDebug() << "gotEntityScriptDetails" << scriptDetails.status << QThread::currentThread();
+#endif
+            map["isRunning"] = isEntityScriptRunning(entityID);
+            map["status"] = EntityScriptStatus_::valueToKey(scriptDetails.status).toLower();
+            map["errorInfo"] = scriptDetails.errorInfo;
+            map["entityID"] = entityID.toString();
+#ifdef DEBUG_ENTITY_STATES
+            {
+                auto debug = QVariantMap();
+                debug["script"] = scriptDetails.scriptText;
+                debug["scriptObject"] = scriptDetails.scriptObject.toVariant();
+                debug["lastModified"] = (qlonglong)scriptDetails.lastModified;
+                debug["sandboxURL"] = scriptDetails.definingSandboxURL;
+                map["debug"] = debug;
+            }
+#endif
+        } else {
+#ifdef DEBUG_ENTITY_STATES
+            qDebug() << "!gotEntityScriptDetails" <<  QThread::currentThread();
+#endif
+            map["isError"] = true;
+            map["errorInfo"] = "Entity script details unavailable";
+            map["entityID"] = entityID.toString();
+        }
+    }
+    return map;
+}
+
+QFuture<QVariant> ScriptManager::getLocalEntityScriptDetails(const EntityItemID& entityID) {
+    return QtConcurrent::run(this, &ScriptManager::cloneEntityScriptDetails, entityID);
+}
+
+bool ScriptManager::getEntityScriptDetails(const EntityItemID& entityID, EntityScriptDetails &details) const {
+    QReadLocker locker { &_entityScriptsLock };
+    auto it = _entityScripts.constFind(entityID);
+    if (it == _entityScripts.constEnd()) {
+        return false;
+    }
+    details = it.value();
+    return true;
+}
+
+bool ScriptManager::hasEntityScriptDetails(const EntityItemID& entityID) const {
+    QReadLocker locker { &_entityScriptsLock };
+    return _entityScripts.contains(entityID);
+}
+
+void ScriptManager::loadEntityScript(const EntityItemID& entityID, const QString& entityScript, bool forceRedownload) {
+    if (QThread::currentThread() != thread()) {
+        QMetaObject::invokeMethod(this, "loadEntityScript",
+            Q_ARG(const EntityItemID&, entityID),
+            Q_ARG(const QString&, entityScript),
+            Q_ARG(bool, forceRedownload)
+        );
+        return;
+    }
+    PROFILE_RANGE(script, __FUNCTION__);
+
+    QSharedPointer<ScriptEngines> scriptEngines(_scriptEngines);
+    if (isStopping() || !scriptEngines || scriptEngines->isStopped()) {
+        qCDebug(scriptengine) << "loadEntityScript.start " << entityID.toString()
+                                     << " but isStopping==" << isStopping()
+                                     << " || engines->isStopped==" << scriptEngines->isStopped();
+        return;
+    }
+
+    if (!hasEntityScriptDetails(entityID)) {
+        // make sure EntityScriptDetails has an entry for this UUID right away
+        // (which allows bailing from the loading/provisioning process early if the Entity gets deleted mid-flight)
+        updateEntityScriptStatus(entityID, EntityScriptStatus::PENDING, "...pending...");
+    }
+
+#ifdef DEBUG_ENTITY_STATES
+    {
+        EntityScriptDetails details;
+        bool hasEntityScript = getEntityScriptDetails(entityID, details);
+        qCDebug(scriptengine) << "loadEntityScript.LOADING: " << entityID.toString()
+            << "(previous: " << (hasEntityScript ? details.status : EntityScriptStatus::PENDING) << ")";
+    }
+#endif
+
+    EntityScriptDetails newDetails;
+    newDetails.scriptText = entityScript;
+    newDetails.status = EntityScriptStatus::LOADING;
+    newDetails.definingSandboxURL = currentSandboxURL;
+    setEntityScriptDetails(entityID, newDetails);
+
+    auto scriptCache = DependencyManager::get<ScriptCache>();
+    // note: see EntityTreeRenderer.cpp for shared pointer lifecycle management
+    std::weak_ptr<ScriptManager> weakRef(shared_from_this());
+    scriptCache->getScriptContents(entityScript,
+        [this, weakRef, entityScript, entityID](const QString& url, const QString& contents, bool isURL, bool success, const QString& status) {
+            std::shared_ptr<ScriptManager> strongRef(weakRef);
+            if (!strongRef) {
+                qCWarning(scriptengine) << "loadEntityScript.contentAvailable -- ScriptManager was deleted during getScriptContents!!";
+                return;
+            }
+            if (isStopping()) {
+#ifdef DEBUG_ENTITY_STATES
+                qCDebug(scriptengine) << "loadEntityScript.contentAvailable -- stopping";
+#endif
+                return;
+            }
+            executeOnScriptThread([=]{
+#ifdef DEBUG_ENTITY_STATES
+                qCDebug(scriptengine) << "loadEntityScript.contentAvailable" << status << entityID.toString();
+#endif
+                if (!isStopping() && hasEntityScriptDetails(entityID)) {
+                    _contentAvailableQueue[entityID] = { entityID, url, contents, isURL, success, status };
+                } else {
+#ifdef DEBUG_ENTITY_STATES
+                    qCDebug(scriptengine) << "loadEntityScript.contentAvailable -- aborting";
+#endif
+                }
+            });
+    }, forceRedownload);
+}
+
+/*@jsdoc
+ * Triggered when the script starts for a user. See also, {@link Script.entityScriptPreloadFinished}.
+ * <p>Note: Can only be connected to via <code>this.preload = function (...) { ... }</code> in the entity script.</p>
+ * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
+ * @function Entities.preload
+ * @param {Uuid} entityID - The ID of the entity that the script is running in.
+ * @returns {Signal}
+ * @example <caption>Get the ID of the entity that a client entity script is running in.</caption>
+ * var entityScript = (function () {
+ *     this.entityID = Uuid.NULL;
+ *
+ *     this.preload = function (entityID) {
+ *         this.entityID = entityID;
+ *         print("Entity ID: " + this.entityID);
+ *     };
+ * });
+ *
+ * var entityID = Entities.addEntity({
+ *     type: "Box",
+ *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
+ *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
+ *     color: { red: 255, green: 0, blue: 0 },
+ *     script: "(" + entityScript + ")",  // Could host the script on a Web server instead.
+ *     lifetime: 300  // Delete after 5 minutes.
+ * });
+ */
+// The JSDoc is for the callEntityScriptMethod() call in this method.
+// since all of these operations can be asynch we will always do the actual work in the response handler
+// for the download
+void ScriptManager::entityScriptContentAvailable(const EntityItemID& entityID, const QString& scriptOrURL, const QString& contents, bool isURL, bool success , const QString& status) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::entityScriptContentAvailable() called on wrong thread ["
+            << QThread::currentThread() << "], invoking on correct thread [" << thread()
+            << "]  " "entityID:" << entityID << "scriptOrURL:" << scriptOrURL << "contents:"
+            << contents << "isURL:" << isURL << "success:" << success;
+#endif
+
+        QMetaObject::invokeMethod(this, "entityScriptContentAvailable",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, scriptOrURL),
+                                  Q_ARG(const QString&, contents),
+                                  Q_ARG(bool, isURL),
+                                  Q_ARG(bool, success),
+                                  Q_ARG(const QString&, status));
+        return;
+    }
+
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::entityScriptContentAvailable() thread [" << QThread::currentThread() << "] expected thread [" << thread() << "]";
+#endif
+
+    auto scriptCache = DependencyManager::get<ScriptCache>();
+    bool isFileUrl = isURL && scriptOrURL.startsWith("file://");
+    auto fileName = isURL ? scriptOrURL : "about:EmbeddedEntityScript";
+
+    QString entityScript;
+    {
+        QWriteLocker locker { &_entityScriptsLock };
+        entityScript = _entityScripts[entityID].scriptText;
+    }
+
+    EntityScriptDetails newDetails;
+    newDetails.scriptText = scriptOrURL;
+
+    // If an error happens below, we want to update newDetails with the new status info
+    // and also abort any pending Entity loads that are waiting on the exact same script URL.
+    auto setError = [&](const QString &errorInfo, const EntityScriptStatus& status) {
+        newDetails.errorInfo = errorInfo;
+        newDetails.status = status;
+        setEntityScriptDetails(entityID, newDetails);
+    };
+
+    // NETWORK / FILESYSTEM ERRORS
+    if (!success) {
+        setError("Failed to load script (" + status + ")", EntityScriptStatus::ERROR_LOADING_SCRIPT);
+        return;
+    }
+
+    // SYNTAX ERRORS
+    auto syntaxError = _engine->lintScript(contents, fileName);
+    if (syntaxError.isError()) {
+        auto message = syntaxError.property("formatted").toString();
+        if (message.isEmpty()) {
+            message = syntaxError.toString();
+        }
+        setError(QString("Bad syntax (%1)").arg(message), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+        syntaxError.setProperty("detail", entityID.toString());
+        emit unhandledException(syntaxError);
+        return;
+    }
+    auto program = _engine->newProgram( contents, fileName );
+    if (!program) {
+        setError("Bad program (isNull)", EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+        emit unhandledException(_engine->makeError(_engine->newValue("program.isNull")));
+        return; // done processing script
+    }
+
+    if (isURL) {
+        setParentURL(scriptOrURL);
+    }
+
+    // SANITY/PERFORMANCE CHECK USING SANDBOX
+    const int SANDBOX_TIMEOUT = 0.25 * MSECS_PER_SECOND;
+    ScriptEnginePointer sandbox = newScriptEngine();
+    sandbox->setProcessEventsInterval(SANDBOX_TIMEOUT);
+    ScriptValue testConstructor, exception;
+    if (atoi(getenv("UNSAFE_ENTITY_SCRIPTS") ? getenv("UNSAFE_ENTITY_SCRIPTS") : "0"))
+    {
+        QTimer timeout;
+        timeout.setSingleShot(true);
+        timeout.start(SANDBOX_TIMEOUT);
+        connect(&timeout, &QTimer::timeout, [=, &sandbox]{
+                qCDebug(scriptengine) << "ScriptManager::entityScriptContentAvailable timeout";
+
+                // Guard against infinite loops and non-performant code
+                sandbox->raiseException(
+                    sandbox->makeError(sandbox->newValue(QString("Timed out (entity constructors are limited to %1ms)").arg(SANDBOX_TIMEOUT)))
+                );
+        });
+
+        testConstructor = sandbox->evaluate(program);
+
+        if (sandbox->hasUncaughtException()) {
+            exception = sandbox->cloneUncaughtException(QString("(preflight %1)").arg(entityID.toString()));
+            sandbox->clearExceptions();
+        } else if (testConstructor.isError()) {
+            exception = testConstructor;
+        }
+    } else {
+        // ENTITY SCRIPT WHITELIST STARTS HERE
+        auto nodeList = DependencyManager::get<NodeList>();
+        bool passList = false;  // assume unsafe
+        QString whitelistPrefix = "[WHITELIST ENTITY SCRIPTS]";
+        QList<QString> safeURLPrefixes = { "file:///", "atp:", "cache:" };
+        safeURLPrefixes += qEnvironmentVariable("EXTRA_WHITELIST").trimmed().split(QRegExp("\\s*,\\s*"), Qt::SkipEmptyParts);
+
+        // Entity Script Whitelist toggle check.
+        Setting::Handle<bool> whitelistEnabled {"private/whitelistEnabled", false };
+                
+        if (!whitelistEnabled.get()) {
+            passList = true;
+        }
+        
+        // Pull SAFEURLS from the Interface.JSON settings.
+        QVariant raw = Setting::Handle<QVariant>("private/settingsSafeURLS").get();
+        QStringList settingsSafeURLS = raw.toString().trimmed().split(QRegExp("\\s*[,\r\n]+\\s*"), Qt::SkipEmptyParts);
+        safeURLPrefixes += settingsSafeURLS;
+        // END Pull SAFEURLS from the Interface.JSON settings.
+        
+        // Get current domain whitelist bypass, in case an entire domain is whitelisted.
+        QString currentDomain = DependencyManager::get<AddressManager>()->getDomainURL().host();
+        
+        QString domainSafeIP = nodeList->getDomainHandler().getHostname();
+        QString domainSafeURL = URL_SCHEME_VIRCADIA + "://" + currentDomain;
+        for (const auto& str : safeURLPrefixes) {
+            if (domainSafeURL.startsWith(str) || domainSafeIP.startsWith(str)) {
+                qCDebug(scriptengine) << whitelistPrefix << "Whitelist Bypassed, entire domain is whitelisted. Current Domain Host: " 
+                    << nodeList->getDomainHandler().getHostname()
+                    << "Current Domain: " << currentDomain;
+                passList = true;
+            }
+        }
+        // END bypass whitelist based on current domain.
+
+        // Start processing scripts through the whitelist.
+        if (ScriptManager::getContext() == "entity_server") { // If running on the server, do not engage whitelist.
+            passList = true;
+        } else if (!passList) { // If waved through, do not engage whitelist.
+            for (const auto& str : safeURLPrefixes) {
+                qCDebug(scriptengine) << whitelistPrefix << "Script URL: " << scriptOrURL << "TESTING AGAINST" << str << "RESULTS IN"
+                    << scriptOrURL.startsWith(str);
+                if (!str.isEmpty() && scriptOrURL.startsWith(str)) {
+                    passList = true;
+                    qCDebug(scriptengine) << whitelistPrefix << "Script approved.";
+                    break; // Bail early since we found a match.
+                }
+            }
+        }
+        // END processing of scripts through the whitelist.
+
+        if (!passList) { // If the entity failed to pass for any reason, it's blocked and an error is thrown.
+            qCDebug(scriptengine) << whitelistPrefix << "(disabled entity script)" << entityID.toString() << scriptOrURL;
+            exception = _engine->makeError(_engine->newValue("UNSAFE_ENTITY_SCRIPTS == 0"));
+        } else {
+            QTimer timeout;
+            timeout.setSingleShot(true);
+            timeout.start(SANDBOX_TIMEOUT);
+            connect(&timeout, &QTimer::timeout, [=, &sandbox] {
+                qCDebug(scriptengine) << "ScriptManager::entityScriptContentAvailable timeout";
+
+                // Guard against infinite loops and non-performant code
+                sandbox->raiseException(
+                    sandbox->makeError(sandbox->newValue(QString("Timed out (entity constructors are limited to %1ms)").arg(SANDBOX_TIMEOUT))));
+            });
+
+            testConstructor = sandbox->evaluate(program);
+
+            if (sandbox->hasUncaughtException()) {
+                exception = sandbox->cloneUncaughtException(QString("(preflight %1)").arg(entityID.toString()));
+                sandbox->clearExceptions();
+            } else if (testConstructor.isError()) {
+                exception = testConstructor;
+            }
+        }
+      // ENTITY SCRIPT WHITELIST ENDS HERE, uncomment below for original full disabling.
+
+      // qDebug() << "(disabled entity script)" << entityID.toString() << scriptOrURL;
+      // exception = makeError("UNSAFE_ENTITY_SCRIPTS == 0");
+    }
+
+    if (exception.isError()) {
+      // create a local copy using makeError to decouple from the sandbox engine
+      exception = _engine->makeError(exception);
+      setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+      emit unhandledException(exception);
+      return;
+    }
+
+    // CONSTRUCTOR VIABILITY
+    if (!testConstructor.isFunction()) {
+        QString testConstructorType = QString(testConstructor.toVariant().typeName());
+        if (testConstructorType == "") {
+            testConstructorType = "empty";
+        }
+        QString testConstructorValue = testConstructor.toString();
+        if (testConstructorValue.size() > MAX_DEBUG_VALUE_LENGTH) {
+            testConstructorValue = testConstructorValue.mid(0, MAX_DEBUG_VALUE_LENGTH) + "...";
+        }
+        auto message = QString("failed to load entity script -- expected a function, got %1, %2")
+            .arg(testConstructorType).arg(testConstructorValue);
+
+        auto err = _engine->makeError(_engine->newValue(message));
+        err.setProperty("fileName", scriptOrURL);
+        err.setProperty("detail", "(constructor " + entityID.toString() + ")");
+
+        setError("Could not find constructor (" + testConstructorType + ")", EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+        emit unhandledException(err);
+        return; // done processing script
+    }
+
+    // (this feeds into refreshFileScript)
+    int64_t lastModified = 0;
+    if (isFileUrl) {
+        QString file = QUrl(scriptOrURL).toLocalFile();
+        lastModified = (quint64)QFileInfo(file).lastModified().toMSecsSinceEpoch();
+    }
+
+    // THE ACTUAL EVALUATION AND CONSTRUCTION
+    ScriptValue entityScriptConstructor, entityScriptObject;
+    QUrl sandboxURL = currentSandboxURL.isEmpty() ? scriptOrURL : currentSandboxURL;
+    auto initialization = [&]{
+        entityScriptConstructor = _engine->evaluate(contents, fileName);
+        entityScriptObject = entityScriptConstructor.construct();
+
+        if (_engine->hasUncaughtException()) {
+            entityScriptObject = _engine->cloneUncaughtException("(construct " + entityID.toString() + ")");
+            _engine->clearExceptions();
+        }
+    };
+
+    doWithEnvironment(entityID, sandboxURL, initialization);
+
+    if (entityScriptObject.isError()) {
+        auto exception = entityScriptObject;
+        setError(formatException(exception, _enableExtendedJSExceptions.get()), EntityScriptStatus::ERROR_RUNNING_SCRIPT);
+        emit unhandledException(exception);
+        return;
+    }
+
+    // ... AND WE HAVE LIFTOFF
+    newDetails.status = EntityScriptStatus::RUNNING;
+    newDetails.scriptObject = entityScriptObject;
+    newDetails.lastModified = lastModified;
+    newDetails.definingSandboxURL = sandboxURL;
+    setEntityScriptDetails(entityID, newDetails);
+
+    if (isURL) {
+        setParentURL("");
+    }
+
+    // if we got this far, then call the preload method
+    callEntityScriptMethod(entityID, "preload");
+
+    emit entityScriptPreloadFinished(entityID);
+}
+
+/*@jsdoc
+ * Triggered when the script terminates for a user.
+ * <p>Note: Can only be connected to via <code>this.unoad = function () { ... }</code> in the entity script.</p>
+ * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
+ * @function Entities.unload
+ * @param {Uuid} entityID - The ID of the entity that the script is running in.
+ * @returns {Signal}
+ */
+// The JSDoc is for the callEntityScriptMethod() call in this method.
+void ScriptManager::unloadEntityScript(const EntityItemID& entityID, bool shouldRemoveFromMap) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::unloadEntityScript() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
+            "entityID:" << entityID;
+#endif
+
+        QMetaObject::invokeMethod(this, "unloadEntityScript",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(bool, shouldRemoveFromMap));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::unloadEntityScript() called on correct thread [" << thread() << "]  "
+        "entityID:" << entityID;
+#endif
+
+    EntityScriptDetails oldDetails;
+    if (getEntityScriptDetails(entityID, oldDetails)) {
+        auto scriptText = oldDetails.scriptText;
+
+        if (isEntityScriptRunning(entityID)) {
+            callEntityScriptMethod(entityID, "unload");
+        }
+#ifdef DEBUG_ENTITY_STATES
+        else {
+            qCDebug(scriptengine) << "unload called while !running" << entityID << oldDetails.status;
+        }
+#endif
+        if (shouldRemoveFromMap) {
+            // this was a deleted entity, we've been asked to remove it from the map
+            {
+                QWriteLocker locker { &_entityScriptsLock };
+                _entityScripts.remove(entityID);
+            }
+            emit entityScriptDetailsUpdated();
+        } else if (oldDetails.status != EntityScriptStatus::UNLOADED) {
+            EntityScriptDetails newDetails;
+            newDetails.status = EntityScriptStatus::UNLOADED;
+            newDetails.lastModified = QDateTime::currentMSecsSinceEpoch();
+            // keep scriptText populated for the current need to "debouce" duplicate calls to unloadEntityScript
+            newDetails.scriptText = scriptText;
+            setEntityScriptDetails(entityID, newDetails);
+        }
+
+        stopAllTimersForEntityScript(entityID);
+    }
+}
+
+QList<EntityItemID> ScriptManager::getListOfEntityScriptIDs() {
+    QReadLocker locker{ &_entityScriptsLock };
+    return _entityScripts.keys();
+}
+
+void ScriptManager::unloadAllEntityScripts(bool blockingCall) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::unloadAllEntityScripts() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
+#endif
+
+        QMetaObject::invokeMethod(this, "unloadAllEntityScripts",
+            blockingCall ? Qt::BlockingQueuedConnection : Qt::QueuedConnection);
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::unloadAllEntityScripts() called on correct thread [" << thread() << "]";
+#endif
+
+    QList<EntityItemID> keys;
+    {
+        QReadLocker locker{ &_entityScriptsLock };
+        keys = _entityScripts.keys();
+    }
+    foreach(const EntityItemID& entityID, keys) {
+        unloadEntityScript(entityID);
+    }
+    {
+        QWriteLocker locker{ &_entityScriptsLock };
+        _entityScripts.clear();
+    }
+    emit entityScriptDetailsUpdated();
+
+#ifdef DEBUG_ENGINE_STATE
+    _debugDump(
+        "---- CURRENT STATE OF ENGINE: --------------------------",
+        globalObject(),
+        "--------------------------------------------------------"
+    );
+#endif // DEBUG_ENGINE_STATE
+}
+
+void ScriptManager::refreshFileScript(const EntityItemID& entityID) {
+    if (!HIFI_AUTOREFRESH_FILE_SCRIPTS || !hasEntityScriptDetails(entityID)) {
+        return;
+    }
+
+    static bool recurseGuard = false;
+    if (recurseGuard) {
+        return;
+    }
+    recurseGuard = true;
+
+    EntityScriptDetails details;
+    {
+        QWriteLocker locker { &_entityScriptsLock };
+        details = _entityScripts[entityID];
+    }
+    // Check to see if a file based script needs to be reloaded (easier debugging)
+    if (details.lastModified > 0) {
+        QString filePath = QUrl(details.scriptText).toLocalFile();
+        auto lastModified = QFileInfo(filePath).lastModified().toMSecsSinceEpoch();
+        if (lastModified > details.lastModified) {
+            scriptInfoMessage("Reloading modified script " + details.scriptText);
+            loadEntityScript(entityID, details.scriptText, true);
+        }
+    }
+    recurseGuard = false;
+}
+
+// Execute operation in the appropriate context for (the possibly empty) entityID.
+// Even if entityID is supplied as currentEntityIdentifier, this still documents the source
+// of the code being executed (e.g., if we ever sandbox different entity scripts, or provide different
+// global values for different entity scripts).
+void ScriptManager::doWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, std::function<void()> operation) {
+    EntityItemID oldIdentifier = currentEntityIdentifier;
+    QUrl oldSandboxURL = currentSandboxURL;
+    currentEntityIdentifier = entityID;
+    currentSandboxURL = sandboxURL;
+
+#if DEBUG_CURRENT_ENTITY
+    ScriptValue oldData = this->globalObject().property("debugEntityID");
+    this->globalObject().setProperty("debugEntityID", entityID.toScriptValue(this)); // Make the entityID available to javascript as a global.
+    operation();
+    this->globalObject().setProperty("debugEntityID", oldData);
+#else
+    operation();
+#endif
+    _engine->maybeEmitUncaughtException(!entityID.isNull() ? entityID.toString() : __FUNCTION__);
+    currentEntityIdentifier = oldIdentifier;
+    currentSandboxURL = oldSandboxURL;
+}
+
+void ScriptManager::callWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, const ScriptValue& function, const ScriptValue& thisObject, const ScriptValueList& args) {
+    auto operation = [&]() {
+        function.call(thisObject, args);
+    };
+    doWithEnvironment(entityID, sandboxURL, operation);
+}
+
+void ScriptManager::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const QStringList& params, const QUuid& remoteCallerID) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
+            "entityID:" << entityID << "methodName:" << methodName;
+#endif
+
+        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, methodName),
+                                  Q_ARG(const QStringList&, params),
+                                  Q_ARG(const QUuid&, remoteCallerID));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
+        "entityID:" << entityID << "methodName:" << methodName;
+#endif
+
+    if (HIFI_AUTOREFRESH_FILE_SCRIPTS && methodName != "unload") {
+        refreshFileScript(entityID);
+    }
+    if (isEntityScriptRunning(entityID)) {
+        EntityScriptDetails details;
+        {
+            QWriteLocker locker { &_entityScriptsLock };
+            details = _entityScripts[entityID];
+        }
+        ScriptValue entityScript = details.scriptObject;  // previously loaded
+
+        // If this is a remote call, we need to check to see if the function is remotely callable
+        // we do this by checking for the existance of the 'remotelyCallable' property on the
+        // entityScript. And we confirm that the method name is included. If this fails, the
+        // function will not be called.
+        bool callAllowed = false;
+        if (remoteCallerID == QUuid()) {
+            callAllowed = true;
+        } else {
+            if (entityScript.property("remotelyCallable").isArray()) {
+                auto callables = entityScript.property("remotelyCallable");
+                auto callableCount = callables.property("length").toInteger();
+                for (int i = 0; i < callableCount; i++) {
+                    auto callable = callables.property(i).toString();
+                    if (callable == methodName) {
+                        callAllowed = true;
+                        break;
+                    }
+                }
+            }
+            if (!callAllowed) {
+                qDebug() << "Method [" << methodName << "] not remotely callable.";
+            }
+        }
+
+        if (callAllowed && entityScript.property(methodName).isFunction()) {
+            auto scriptEngine = engine().get();
+
+            ScriptValueList args;
+            args << EntityItemIDtoScriptValue(scriptEngine, entityID);
+            args << scriptValueFromSequence(scriptEngine, params);
+
+            ScriptValue oldData = scriptEngine->globalObject().property("Script").property("remoteCallerID");
+            scriptEngine->globalObject().property("Script").setProperty("remoteCallerID", remoteCallerID.toString()); // Make the remoteCallerID available to javascript as a global.
+            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
+            scriptEngine->globalObject().property("Script").setProperty("remoteCallerID", oldData);
+        }
+    }
+}
+
+void ScriptManager::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const PointerEvent& event) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
+            "entityID:" << entityID << "methodName:" << methodName << "event: mouseEvent";
+#endif
+
+        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, methodName),
+                                  Q_ARG(const PointerEvent&, event));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
+        "entityID:" << entityID << "methodName:" << methodName << "event: pointerEvent";
+#endif
+
+    if (HIFI_AUTOREFRESH_FILE_SCRIPTS) {
+        refreshFileScript(entityID);
+    }
+    if (isEntityScriptRunning(entityID)) {
+        EntityScriptDetails details;
+        {
+            QWriteLocker locker { &_entityScriptsLock };
+            details = _entityScripts[entityID];
+        }
+        ScriptValue entityScript = details.scriptObject;  // previously loaded
+        if (entityScript.property(methodName).isFunction()) {
+            auto scriptEngine = engine().get();
+
+            ScriptValueList args;
+            args << EntityItemIDtoScriptValue(scriptEngine, entityID);
+            args << event.toScriptValue(scriptEngine);
+            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
+        }
+    }
+}
+
+void ScriptManager::callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const EntityItemID& otherID, const Collision& collision) {
+    if (QThread::currentThread() != thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptManager::callEntityScriptMethod() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  "
+            "entityID:" << entityID << "methodName:" << methodName << "otherID:" << otherID << "collision: collision";
+#endif
+
+        QMetaObject::invokeMethod(this, "callEntityScriptMethod",
+                                  Q_ARG(const EntityItemID&, entityID),
+                                  Q_ARG(const QString&, methodName),
+                                  Q_ARG(const EntityItemID&, otherID),
+                                  Q_ARG(const Collision&, collision));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptManager::callEntityScriptMethod() called on correct thread [" << thread() << "]  "
+        "entityID:" << entityID << "methodName:" << methodName << "otherID:" << otherID << "collision: collision";
+#endif
+
+    if (HIFI_AUTOREFRESH_FILE_SCRIPTS) {
+        refreshFileScript(entityID);
+    }
+    if (isEntityScriptRunning(entityID)) {
+        EntityScriptDetails details;
+        {
+            QWriteLocker locker { &_entityScriptsLock };
+            details = _entityScripts[entityID];
+        }
+        ScriptValue entityScript = details.scriptObject;  // previously loaded
+        if (entityScript.property(methodName).isFunction()) {
+            auto scriptEngine = engine().get();
+
+            ScriptValueList args;
+            args << EntityItemIDtoScriptValue(scriptEngine, entityID);
+            args << EntityItemIDtoScriptValue(scriptEngine, otherID);
+            args << collisionToScriptValue(scriptEngine, collision);
+            callWithEnvironment(entityID, details.definingSandboxURL, entityScript.property(methodName), entityScript, args);
+        }
+    }
+}
+
+QString ScriptManager::getExternalPath(ExternalResource::Bucket bucket, const QString& path) {
+    return ExternalResource::getInstance()->getUrl(bucket, path);
+}
+
+QString ScriptManager::formatException(const ScriptValue& exception, bool includeExtendedDetails) {
+    if (!_engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return QString();
+    }
+    QString note{ "UncaughtException" };
+    QString result;
+
+    if (!exception.isObject()) {
+        return result;
+    }
+    const auto message = exception.toString();
+    const auto fileName = exception.property("fileName").toString();
+    const auto lineNumber = exception.property("lineNumber").toString();
+    const auto stacktrace = exception.property("stack").toString();
+
+    if (includeExtendedDetails) {
+        // Display additional exception / troubleshooting hints that can be added via the custom Error .detail property
+        // Example difference:
+        //   [UncaughtExceptions] Error: Can't find variable: foobar in atp:/myentity.js\n...
+        //   [UncaughtException (construct {1eb5d3fa-23b1-411c-af83-163af7220e3f})] Error: Can't find variable: foobar in atp:/myentity.js\n...
+        if (exception.property("detail").isValid()) {
+            note += " " + exception.property("detail").toString();
+        }
+    }
+
+    result = QString(SCRIPT_EXCEPTION_FORMAT).arg(note, message, fileName, lineNumber);
+    if (!stacktrace.isEmpty()) {
+        result += QString("\n[Backtrace]%1%2").arg(SCRIPT_BACKTRACE_SEP).arg(stacktrace);
+    }
+    return result;
+}
+
+ScriptValue ScriptManager::evaluate(const QString& program, const QString& fileName) {
+    return _engine->evaluate(program, fileName);
+}
+
+void ScriptManager::requestGarbageCollection() {
+    _engine->requestCollectGarbage();
+}
diff --git a/libraries/script-engine/src/ScriptManager.h b/libraries/script-engine/src/ScriptManager.h
new file mode 100644
index 00000000000..ae9571cb026
--- /dev/null
+++ b/libraries/script-engine/src/ScriptManager.h
@@ -0,0 +1,988 @@
+//
+//  ScriptManager.h
+//  libraries/script-engine/src
+//
+//  Created by Brad Hefta-Gaub on 12/14/13.
+//  Copyright 2013 High Fidelity, Inc.
+//  Copyright 2020 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptManager_h
+#define hifi_ScriptManager_h
+
+#include <atomic>
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <unordered_map>
+#include <mutex>
+
+#include <QtCore/QFuture>
+#include <QtCore/QHash>
+#include <QtCore/QObject>
+#include <QtCore/QReadWriteLock>
+#include <QtCore/QSet>
+#include <QtCore/QSharedPointer>
+#include <QtCore/QString>
+#include <QtCore/QTimer>
+#include <QtCore/QUrl>
+#include <QtCore/QVariant>
+
+#include "EntityItemID.h"
+#include "EntitiesScriptEngineProvider.h"
+#include "EntityScriptUtils.h"
+#include <ExternalResource.h>
+#include <SettingHandle.h>
+
+#include "AssetScriptingInterface.h"
+#include "ConsoleScriptingInterface.h"
+#include "Mat4.h"
+#include "PointerEvent.h"
+#include "Quat.h"
+#include "ScriptUUID.h"
+#include "ScriptValue.h"
+#include "Vec3.h"
+
+static const QString NO_SCRIPT("");
+
+static const int SCRIPT_FPS = 60;
+static const int DEFAULT_MAX_ENTITY_PPS = 9000;
+static const int DEFAULT_ENTITY_PPS_PER_SCRIPT = 900;
+
+class ScriptEngine;
+class ScriptEngines;
+class ScriptManager;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+using ScriptManagerPointer = std::shared_ptr<ScriptManager>;
+using ScriptValueList = QList<ScriptValue>;
+
+Q_DECLARE_METATYPE(ScriptManagerPointer)
+
+const int QTREGISTER_QTimerStar = qRegisterMetaType<QTimer*>();
+
+class CallbackData {
+public:
+    ScriptValue function;
+    EntityItemID definingEntityIdentifier;
+    QUrl definingSandboxURL;
+};
+
+class DeferredLoadEntity {
+public:
+    EntityItemID entityID;
+    QString entityScript;
+    //bool forceRedownload;
+};
+
+struct EntityScriptContentAvailable {
+    EntityItemID entityID;
+    QString scriptOrURL;
+    QString contents;
+    bool isURL;
+    bool success;
+    QString status;
+};
+
+typedef std::unordered_map<EntityItemID, EntityScriptContentAvailable> EntityScriptContentAvailableMap;
+
+typedef QList<CallbackData> CallbackList;
+typedef QHash<QString, CallbackList> RegisteredEventHandlers;
+
+class EntityScriptDetails {
+public:
+    EntityScriptStatus status { EntityScriptStatus::PENDING };
+
+    // If status indicates an error, this contains a human-readable string giving more information about the error.
+    QString errorInfo { "" };
+
+    QString scriptText { "" };
+    ScriptValue scriptObject{ ScriptValue() };
+    int64_t lastModified { 0 };
+    QUrl definingSandboxURL { QUrl("about:EntityScript") };
+};
+
+// declare a static script initializer
+#define STATIC_SCRIPT_INITIALIZER(init)                                     \
+    static ScriptManager::StaticInitializerNode static_script_initializer_(init);
+
+/*@jsdoc
+ * The <code>Script</code> API provides facilities for working with scripts.
+ *
+ * @namespace Script
+ *
+ * @hifi-interface
+ * @hifi-client-entity
+ * @hifi-avatar
+ * @hifi-server-entity
+ * @hifi-assignment-client
+ *
+ * @property {string} context - The context that the script is running in:
+ *     <ul>
+ *       <li><code>"client"</code>: An Interface or avatar script.</li>
+ *       <li><code>"entity_client"</code>: A client entity script.</li>
+ *       <li><code>"entity_server"</code>: A server entity script.</li>
+ *       <li><code>"agent"</code>: An assignment client script.</li>
+ *     </ul>
+ *     <em>Read-only.</em>
+ * @property {string} type - The type of script that is running:
+ *     <ul>
+ *       <li><code>"client"</code>: An Interface script.</li>
+ *       <li><code>"entity_client"</code>: A client entity script.</li>
+ *       <li><code>"avatar"</code>: An avatar script.</li>
+ *       <li><code>"entity_server"</code>: A server entity script.</li>
+ *       <li><code>"agent"</code>: An assignment client script.</li>
+ *     </ul>
+ *     <em>Read-only.</em>
+ * @property {string} filename - The filename of the script file.
+ *     <em>Read-only.</em>
+ * @property {Script.ResourceBuckets} ExternalPaths - External resource buckets.
+ */
+/// The main class managing a scripting engine.  Also provides the <code><a href="https://apidocs.vircadia.dev/Script.html">Script</a></code> scripting interface
+class ScriptManager : public QObject, public EntitiesScriptEngineProvider, public std::enable_shared_from_this<ScriptManager> {
+    Q_OBJECT
+    Q_PROPERTY(QString context READ getContext)
+    Q_PROPERTY(QString type READ getTypeAsString)
+    Q_PROPERTY(QString fileName MEMBER _fileNameString CONSTANT)
+public:
+    static const QString SCRIPT_EXCEPTION_FORMAT;
+    static const QString SCRIPT_BACKTRACE_SEP;
+
+    enum Context {
+        CLIENT_SCRIPT,
+        ENTITY_CLIENT_SCRIPT,
+        ENTITY_SERVER_SCRIPT,
+        AGENT_SCRIPT
+    };
+
+    enum Type {
+        CLIENT,
+        ENTITY_CLIENT,
+        ENTITY_SERVER,
+        AGENT,
+        AVATAR
+    };
+    Q_ENUM(Type);
+
+    static int processLevelMaxRetries;
+    ScriptManager(Context context, const QString& scriptContents = NO_SCRIPT, const QString& fileNameString = QString("about:ScriptEngine"));
+    ~ScriptManager();
+
+    // static initialization support
+    typedef void (*ScriptManagerInitializer)(ScriptManager*);
+    class StaticInitializerNode {
+    public:
+        ScriptManagerInitializer init;
+        StaticInitializerNode* prev;
+        inline StaticInitializerNode(ScriptManagerInitializer&& pInit) : init(std::move(pInit)),prev(nullptr) { registerNewStaticInitializer(this); }
+    };
+    static void registerNewStaticInitializer(StaticInitializerNode* dest);
+
+    /// run the script in a dedicated thread. This will have the side effect of evalulating
+    /// the current script contents and calling run(). Callers will likely want to register the script with external
+    /// services before calling this.
+    void runInThread();
+
+    /// run the script in the callers thread, exit when stop() is called.
+    void run();
+
+    QString getFilename() const;
+
+    inline ScriptEnginePointer engine() { return _engine; }
+
+    QList<EntityItemID> getListOfEntityScriptIDs();
+
+    bool isStopped() const;
+
+    /*@jsdoc
+     * Stops and unloads the current script.
+     * <p><strong>Warning:</strong> If an assignment client script, the script gets restarted after stopping.</p>
+     * @function Script.stop
+     * @param {boolean} [marshal=false] - Marshal.
+     *     <p class="important">Deprecated: This parameter is deprecated and will be removed.</p>
+     * @example <caption>Stop a script after 5s.</caption>
+     * Script.setInterval(function () {
+     *     print("Hello");
+     * }, 1000);
+     *
+     * Script.setTimeout(function () {
+     *     Script.stop(true);
+     * }, 5000);
+     */
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE - this is intended to be a public interface for Agent scripts, and local scripts, but not for EntityScripts
+    Q_INVOKABLE void stop(bool marshal = false);
+
+    // Stop any evaluating scripts and wait for the scripting thread to finish.
+    void waitTillDoneRunning(bool shutdown = false);
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE - these are NOT intended to be public interfaces available to scripts, the are only Q_INVOKABLE so we can
+    //        properly ensure they are only called on the correct thread
+
+    /// if the script engine is not already running, this will download the URL and start the process of seting it up
+    /// to run... NOTE - this is used by Application currently to load the url. We don't really want it to be exposed
+    /// to scripts. we may not need this to be invokable
+    void loadURL(const QUrl& scriptURL, bool reload);
+    bool hasValidScriptSuffix(const QString& scriptFileName);
+
+    /*@jsdoc
+     * Gets the context that the script is running in: Interface/avatar, client entity, server entity, or assignment client.
+     * @function Script.getContext
+     * @returns {string} The context that the script is running in:
+     * <ul>
+     *   <li><code>"client"</code>: An Interface or avatar script.</li>
+     *   <li><code>"entity_client"</code>: A client entity script.</li>
+     *   <li><code>"entity_server"</code>: A server entity script.</li>
+     *   <li><code>"agent"</code>: An assignment client script.</li>
+     * </ul>
+     */
+    Q_INVOKABLE QString getContext() const;
+
+    /*@jsdoc
+     * Checks whether the script is running as an Interface or avatar script.
+     * @function Script.isClientScript
+     * @returns {boolean} <code>true</code> if the script is running as an Interface or avatar script, <code>false</code> if it
+     *     isn't.
+     */
+    Q_INVOKABLE bool isClientScript() const { return _context == CLIENT_SCRIPT; }
+
+    /*@jsdoc
+     * Checks whether the application was compiled as a debug build.
+     * @function Script.isDebugMode
+     * @returns {boolean} <code>true</code> if the application was compiled as a debug build, <code>false</code> if it was
+     *     compiled as a release build.
+     */
+    Q_INVOKABLE bool isDebugMode() const;
+
+    /*@jsdoc
+     * Checks whether the script is running as a client entity script.
+     * @function Script.isEntityClientScript
+     * @returns {boolean} <code>true</code> if the script is running as a client entity script, <code>false</code> if it isn't.
+     */
+    Q_INVOKABLE bool isEntityClientScript() const { return _context == ENTITY_CLIENT_SCRIPT; }
+
+    /*@jsdoc
+     * Checks whether the script is running as a server entity script.
+     * @function Script.isEntityServerScript
+     * @returns {boolean} <code>true</code> if the script is running as a server entity script, <code>false</code> if it isn't.
+     */
+    Q_INVOKABLE bool isEntityServerScript() const { return _context == ENTITY_SERVER_SCRIPT; }
+
+    /*@jsdoc
+     * Checks whether the script is running as an assignment client script.
+     * @function Script.isAgentScript
+     * @returns {boolean} <code>true</code> if the script is running as an assignment client script, <code>false</code> if it
+     *     isn't.
+     */
+    Q_INVOKABLE bool isAgentScript() const { return _context == AGENT_SCRIPT; }
+
+    /*@jsdoc
+     * registers a global object by name.
+     * @function Script.registerValue
+     * @param {string} valueName
+     * @param {value} value
+     */
+    /// registers a global object by name
+    Q_INVOKABLE void registerValue(const QString& valueName, ScriptValue value);
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE - these are intended to be public interfaces available to scripts
+
+    /*@jsdoc
+     * @function Script.formatExecption
+     * @param {object} exception - Exception.
+     * @param {boolean} inludeExtendeDetails - Include extended details.
+     * @returns {string} String.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE QString formatException(const ScriptValue& exception, bool includeExtendedDetails);
+
+    /*@jsdoc
+     * Adds a function to the list of functions called when a particular event occurs on a particular entity.
+     * <p>See also, the {@link Entities} API.</p>
+     * @function Script.addEventHandler
+     * @param {Uuid} entityID - The ID of the entity.
+     * @param {Script.EntityEvent} eventName - The name of the event.
+     * @param {Script~entityEventCallback|Script~pointerEventCallback|Script~collisionEventCallback} handler - The function to
+     *     call when the event occurs on the entity. It can be either the name of a function or an in-line definition.
+     * @example <caption>Report when a mouse press occurs on a particular entity.</caption>
+     * var entityID = Entities.addEntity({
+     *     type: "Box",
+     *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
+     *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
+     *     lifetime: 300  // Delete after 5 minutes.
+     * });
+     *
+     * function reportMousePress(entityID, event) {
+     *     print("Mouse pressed on entity: " + JSON.stringify(event));
+     * }
+     *
+     * Script.addEventHandler(entityID, "mousePressOnEntity", reportMousePress);
+     */
+    Q_INVOKABLE void addEventHandler(const EntityItemID& entityID, const QString& eventName, const ScriptValue& handler);
+
+    /*@jsdoc
+     * Removes a function from the list of functions called when an entity event occurs on a particular entity.
+     * <p>See also, the {@link Entities} API.</p>
+     * @function Script.removeEventHandler
+     * @param {Uuid} entityID - The ID of the entity.
+     * @param {Script.EntityEvent} eventName - The name of the entity event.
+     * @param {function} handler - The name of the function to no longer call when the entity event occurs on the entity.
+     */
+    Q_INVOKABLE void removeEventHandler(const EntityItemID& entityID, const QString& eventName, const ScriptValue& handler);
+
+    /*@jsdoc
+     * Starts running another script in Interface, if it isn't already running. The script is not automatically loaded next
+     * time Interface starts.
+     * <p class="availableIn"><strong>Supported Script Types:</strong> Interface Scripts &bull; Avatar Scripts</p>
+     * <p>See also, {@link ScriptDiscoveryService.loadScript}.</p>
+     * @function Script.load
+     * @param {string} filename - The URL of the script to load. This can be relative to the current script's URL.
+     * @example <caption>Load a script from another script.</caption>
+     * // First file: scriptA.js
+     * print("This is script A");
+     *
+     * // Second file: scriptB.js
+     * print("This is script B");
+     * Script.load("scriptA.js");
+     *
+     * // If you run scriptB.js you should see both scripts in the Running Scripts dialog.
+     * // And you should see the following output:
+     * // This is script B
+     * // This is script A
+     */
+    Q_INVOKABLE void load(const QString& loadfile);
+
+    /*@jsdoc
+     * Includes JavaScript from other files in the current script. If a callback is specified, the files are loaded and
+     * included asynchronously, otherwise they are included synchronously (i.e., script execution blocks while the files are
+     * included).
+     * @function Script.include
+     * @variation 0
+     * @param {string[]} filenames - The URLs of the scripts to include. Each can be relative to the current script.
+     * @param {function} [callback=null] - The function to call back when the scripts have been included. It can be either the
+     *     name of a function or an in-line definition.
+     */
+    Q_INVOKABLE void include(const QStringList& includeFiles, const ScriptValue& callback = ScriptValue());
+
+    /*@jsdoc
+     * Includes JavaScript from another file in the current script. If a callback is specified, the file is loaded and included
+     * asynchronously, otherwise it is included synchronously (i.e., script execution blocks while the file is included).
+     * @function Script.include
+     * @param {string} filename - The URL of the script to include. It can be relative to the current script.
+     * @param {function} [callback=null] - The function to call back when the script has been included. It can be either the
+     *     name of a function or an in-line definition.
+     * @example <caption>Include a script file asynchronously.</caption>
+     * // First file: scriptA.js
+     * print("This is script A");
+     *
+     * // Second file: scriptB.js
+     * print("This is script B");
+     * Script.include("scriptA.js", function () {
+     *     print("Script A has been included");
+     * });
+     *
+     * // If you run scriptB.js you should see only scriptB.js in the running scripts list.
+     * // And you should see the following output:
+     * // This is script B
+     * // This is script A
+     * // Script A has been included
+     */
+    Q_INVOKABLE void include(const QString& includeFile, const ScriptValue& callback = ScriptValue());
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // MODULE related methods
+
+    /*@jsdoc
+     * Provides access to methods or objects provided in an external JavaScript or JSON file. 
+     * See {@link https://docs.vircadia.com/script/js-tips.html} for further details.
+     * @function Script.require
+     * @param {string} module - The module to use. May be a JavaScript file, a JSON file, or the name of a system module such
+     *     as <code>"appUi"</code> (i.e., the "appUi.js" system module JavaScript file).
+     * @returns {object|array} The value assigned to <code>module.exports</code> in the JavaScript file, or the value defined
+     *     in the JSON file.
+     */
+    Q_INVOKABLE ScriptValue require(const QString& moduleId);
+
+    /*@jsdoc
+     * @function Script.resetModuleCache
+     * @param {boolean} [deleteScriptCache=false] - Delete script cache.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void resetModuleCache(bool deleteScriptCache = false);
+
+    ScriptValue currentModule();
+    bool registerModuleWithParent(const ScriptValue& module, const ScriptValue& parent);
+    ScriptValue newModule(const QString& modulePath, const ScriptValue& parent = ScriptValue());
+    QVariantMap fetchModuleSource(const QString& modulePath, const bool forceDownload = false);
+    ScriptValue instantiateModule(const ScriptValue& module, const QString& sourceCode);
+
+    ScriptValue evaluate(const QString& program, const QString& fileName = QString());
+
+    /*@jsdoc
+     * Calls a function repeatedly, at a set interval.
+     * @function Script.setInterval
+     * @param {function} function - The function to call. This can be either the name of a function or an in-line definition.
+     * @param {number} interval - The interval at which to call the function, in ms.
+     * @returns {object} A handle to the interval timer. This can be used in {@link Script.clearInterval}.
+     * @example <caption>Print a message every second.</caption>
+     * Script.setInterval(function () {
+     *     print("Interval timer fired");
+     * }, 1000);
+    */
+    Q_INVOKABLE QTimer* setInterval(const ScriptValue& function, int intervalMS);
+
+    /*@jsdoc
+     * Calls a function once, after a delay.
+     * @function Script.setTimeout
+     * @param {function} function - The function to call. This can be either the name of a function or an in-line definition.
+     * @param {number} timeout - The delay after which to call the function, in ms.
+     * @returns {object} A handle to the timeout timer. This can be used in {@link Script.clearTimeout}.
+     * @example <caption>Print a message once, after a second.</caption>
+     * Script.setTimeout(function () {
+     *     print("Timeout timer fired");
+     * }, 1000);
+     */
+    Q_INVOKABLE QTimer* setTimeout(const ScriptValue& function, int timeoutMS);
+
+    /*@jsdoc
+     * Stops an interval timer set by {@link Script.setInterval|setInterval}.
+     * @function Script.clearInterval
+     * @param {object} timer - The interval timer to stop.
+     * @example <caption>Stop an interval timer.</caption>
+     * // Print a message every second.
+     * var timer = Script.setInterval(function () {
+     *     print("Interval timer fired");
+     * }, 1000);
+     *
+     * // Stop the timer after 10 seconds.
+     * Script.setTimeout(function () {
+     *     print("Stop interval timer");
+     *     Script.clearInterval(timer);
+     * }, 10000);
+     */
+    Q_INVOKABLE void clearInterval(QTimer* timer) { stopTimer(timer); }
+
+    /*@jsdoc
+     * Stops a timeout timer set by {@link Script.setTimeout|setTimeout}.
+     * @function Script.clearTimeout
+     * @param {object} timer - The timeout timer to stop.
+     * @example <caption>Stop a timeout timer.</caption>
+     * // Print a message after two seconds.
+     * var timer = Script.setTimeout(function () {
+     *     print("Timer fired");
+     * }, 2000);
+     *
+     * // Uncomment the following line to stop the timer from firing.
+     * //Script.clearTimeout(timer);
+     */
+    Q_INVOKABLE void clearTimeout(QTimer* timer) { stopTimer(timer); }
+
+    /*@jsdoc
+     * Prints a message to the program log and emits {@link Script.printedMessage}.
+     * <p>Alternatively, you can use {@link print} or one of the {@link console} API methods.</p>
+     * @function Script.print
+     * @param {string} message - The message to print.
+     */
+    Q_INVOKABLE void print(const QString& message);
+
+    /*@jsdoc
+     * Resolves a relative path to an absolute path. The relative path is relative to the script's location.
+     * @function Script.resolvePath
+     * @param {string} path - The relative path to resolve.
+     * @returns {string} The absolute path.
+     * @example <caption>Report the directory and filename of the running script.</caption>
+     * print(Script.resolvePath(""));
+     * @example <caption>Report the directory of the running script.</caption>
+     * print(Script.resolvePath("."));
+     * @example <caption>Report the path to a file located relative to the running script.</caption>
+     * print(Script.resolvePath("../assets/sounds/hello.wav"));
+     */
+    Q_INVOKABLE QUrl resolvePath(const QString& path) const;
+
+    /*@jsdoc
+     * Gets the path to the resources directory for QML files.
+     * @function Script.resourcesPath
+     * @returns {string} The path to the resources directory for QML files.
+     */
+    Q_INVOKABLE QUrl resourcesPath() const;
+
+    /*@jsdoc
+     * Starts timing a section of code in order to send usage data about it to Vircadia. Shouldn't be used outside of the
+     * standard scripts.
+     * @function Script.beginProfileRange
+     * @param {string} label - A name that identifies the section of code.
+     */
+    Q_INVOKABLE void beginProfileRange(const QString& label) const;
+
+    /*@jsdoc
+     * Finishes timing a section of code in order to send usage data about it to Vircadia. Shouldn't be used outside of
+     * the standard scripts.
+     * @function Script.endProfileRange
+     * @param {string} label - A name that identifies the section of code.
+     */
+    Q_INVOKABLE void endProfileRange(const QString& label) const;
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // Entity Script Related methods
+
+    /*@jsdoc
+     * Checks whether an entity has an entity script running.
+     * @function Script.isEntityScriptRunning
+     * @param {Uuid} entityID - The ID of the entity.
+     * @returns {boolean} <code>true</code> if the entity has an entity script running, <code>false</code> if it doesn't.
+     */
+    Q_INVOKABLE bool isEntityScriptRunning(const EntityItemID& entityID) {
+        QReadLocker locker { &_entityScriptsLock };
+        auto it = _entityScripts.constFind(entityID);
+        return it != _entityScripts.constEnd() && it->status == EntityScriptStatus::RUNNING;
+    }
+    QVariant cloneEntityScriptDetails(const EntityItemID& entityID);
+    QFuture<QVariant> getLocalEntityScriptDetails(const EntityItemID& entityID) override;
+
+    /*@jsdoc
+     * Manually runs the JavaScript garbage collector which reclaims memory by disposing of objects that are no longer 
+     * reachable.
+     * @function Script.requestGarbageCollection
+     */
+    Q_INVOKABLE void requestGarbageCollection();
+
+    /*@jsdoc
+     * @function Script.loadEntityScript
+     * @param {Uuid} entityID - Entity ID.
+     * @param {string} script - Script.
+     * @param {boolean} forceRedownload - Force re-download.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void loadEntityScript(const EntityItemID& entityID, const QString& entityScript, bool forceRedownload);
+
+    /*@jsdoc
+     * @function Script.unloadEntityScript
+     * @param {Uuid} entityID - Entity ID.
+     * @param {boolean} [shouldRemoveFromMap=false] - Should remove from map.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void unloadEntityScript(const EntityItemID& entityID, bool shouldRemoveFromMap = false); // will call unload method
+
+    /*@jsdoc
+     * @function Script.unloadAllEntityScripts
+     * @param {boolean} [blockingCall=false] - Wait for completion if call moved to another thread.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void unloadAllEntityScripts(bool blockingCall = false);
+
+    /*@jsdoc
+     * Calls a method in an entity script.
+     * @function Script.callEntityScriptMethod
+     * @param {Uuid} entityID - The ID of the entity running the entity script.
+     * @param {string} methodName - The name of the method to call.
+     * @param {string[]} [parameters=[]] - The parameters to call the specified method with.
+     * @param {Uuid} [remoteCallerID=Uuid.NULL] - An ID that identifies the caller.
+     */
+    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName,
+                                            const QStringList& params = QStringList(),
+                                            const QUuid& remoteCallerID = QUuid()) override;
+
+    /*@jsdoc
+     * Calls a method in an entity script.
+     * @function Script.callEntityScriptMethod
+     * @param {Uuid} entityID - Entity ID.
+     * @param {string} methodName - Method name.
+     * @param {PointerEvent} event - Pointer event.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const PointerEvent& event);
+
+    /*@jsdoc
+     * Calls a method in an entity script.
+     * @function Script.callEntityScriptMethod
+     * @param {Uuid} entityID - Entity ID.
+     * @param {string} methodName - Method name.
+     * @param {Uuid} otherID - Other entity ID.
+     * @param {Collision} collision - Collision.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void callEntityScriptMethod(const EntityItemID& entityID, const QString& methodName, const EntityItemID& otherID, const Collision& collision);
+
+    /*@jsdoc
+     * @function Script.generateUUID
+     * @returns {Uuid} A new UUID.
+     * @deprecated This function is deprecated and will be removed. Use {@link Uuid(0).generate|Uuid.generate} instead.
+     */
+    Q_INVOKABLE QUuid generateUUID() { return QUuid::createUuid(); }
+
+    void setType(Type type) { _type = type; };
+    Type getType() { return _type; };
+    QString getTypeAsString() const;
+
+    bool isFinished() const { return _isFinished; } // used by Application and ScriptWidget
+    bool isRunning() const { return _isRunning; } // used by ScriptWidget
+
+    // this is used by code in ScriptEngines.cpp during the "reload all" operation
+    bool isStopping() const { return _isStopping; }
+
+    void disconnectNonEssentialSignals();
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // These are currently used by Application to track if a script is user loaded or not. Consider finding a solution
+    // inside of Application so that the ScriptManager class is not polluted by this notion
+    void setUserLoaded(bool isUserLoaded) { _isUserLoaded = isUserLoaded; }
+    bool isUserLoaded() const { return _isUserLoaded; }
+
+    void setQuitWhenFinished(const bool quitWhenFinished) { _quitWhenFinished = quitWhenFinished; }
+    bool isQuitWhenFinished() const { return _quitWhenFinished; }
+
+    void setEmitScriptUpdatesFunction(std::function<bool()> func) { _emitScriptUpdates = func; }
+
+    void scriptErrorMessage(const QString& message);
+    void scriptWarningMessage(const QString& message);
+    void scriptInfoMessage(const QString& message);
+    void scriptPrintedMessage(const QString& message);
+    void clearDebugLogWindow();
+    int getNumRunningEntityScripts() const;
+    bool getEntityScriptDetails(const EntityItemID& entityID, EntityScriptDetails &details) const;
+    bool hasEntityScriptDetails(const EntityItemID& entityID) const;
+
+    void setScriptEngines(QSharedPointer<ScriptEngines>& scriptEngines) { _scriptEngines = scriptEngines; }
+
+    // call all the registered event handlers on an entity for the specified name.
+    void forwardHandlerCall(const EntityItemID& entityID, const QString& eventName, const ScriptValueList& eventHanderArgs);
+
+    // remove all event handlers for the specified entityID (i.e. the entity is being removed)
+    void removeAllEventHandlers(const EntityItemID& entityID);
+
+
+    /*@jsdoc
+     * Gets the URL for an asset in an external resource bucket. (The location where the bucket is hosted may change over time
+     * but this method will return the asset's current URL.)
+     * @function Script.getExternalPath
+     * @param {Script.ResourceBucket} bucket - The external resource bucket that the asset is in.
+     * @param {string} path - The path within the external resource bucket where the asset is located.
+     *     <p>Normally, this should start with a path or filename to be appended to the bucket URL.
+     *     Alternatively, it can be a relative path starting with <code>./</code> or <code>../</code>, to navigate within the
+     *     resource bucket's URL.</p>
+     * @Returns {string} The URL of an external asset.
+     * @example <caption>Report the URL of a default particle.</caption>
+     * print(Script.getExternalPath(Script.ExternalPaths.Assets, "Bazaar/Assets/Textures/Defaults/Interface/default_particle.png"));
+     * @example <caption>Report the root directory where the Vircadia assets are located.</caption>
+     * print(Script.getExternalPath(Script.ExternalPaths.Assets, "."));
+     */
+    Q_INVOKABLE QString getExternalPath(ExternalResource::Bucket bucket, const QString& path);
+
+public slots:
+
+    /*@jsdoc
+     * @function Script.updateMemoryCost
+     * @param {number} deltaSize - Delta size.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    void updateMemoryCost(const qint64&);
+
+signals:
+
+    /*@jsdoc
+     * @function Script.scriptLoaded
+     * @param {string} filename - File name.
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void scriptLoaded(const QString& scriptFilename);
+
+    /*@jsdoc
+     * @function Script.errorLoadingScript
+     * @param {string} filename - File name.
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void errorLoadingScript(const QString& scriptFilename);
+
+    /*@jsdoc
+     * Triggered frequently at a system-determined interval.
+     * @function Script.update
+     * @param {number} deltaTime - The time since the last update, in s.
+     * @returns {Signal}
+     * @example <caption>Report script update intervals.</caption>
+     * Script.update.connect(function (deltaTime) {
+     *     print("Update: " + deltaTime);
+     * });
+     */
+    void update(float deltaTime);
+
+    /*@jsdoc
+     * Triggered when the script is stopping.
+     * @function Script.scriptEnding
+     * @returns {Signal}
+     * @example <caption>Report when a script is stopping.</caption>
+     * print("Script started");
+     *
+     * Script.scriptEnding.connect(function () {
+     *     print("Script ending");
+     * });
+     *
+     * Script.setTimeout(function () {
+     *     print("Stopping script");
+     *     Script.stop();
+     * }, 1000);
+     */
+    void scriptEnding();
+
+    /*@jsdoc
+     * @function Script.finished
+     * @param {string} filename - File name.
+     * @param {object} engine - Engine.
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void finished(const QString& fileNameString, ScriptManagerPointer);
+
+    /*@jsdoc
+     * Triggered when the script prints a message to the program log via {@link  print}, {@link Script.print},
+     * {@link console.log}, {@link console.debug}, {@link console.group}, {@link console.groupEnd}, {@link console.time}, or
+     * {@link console.timeEnd}.
+     * @function Script.printedMessage
+     * @param {string} message - The message.
+     * @param {string} scriptName - The name of the script that generated the message.
+     * @returns {Signal}
+     */
+    void printedMessage(const QString& message, const QString& scriptName);
+
+    /*@jsdoc
+     * Triggered when the script generates an error, {@link console.error} or {@link console.exception} is called, or
+     * {@link console.assert} is called and fails.
+     * @function Script.errorMessage
+     * @param {string} message - The error message.
+     * @param {string} scriptName - The name of the script that generated the error message.
+     * @returns {Signal}
+     */
+    void errorMessage(const QString& message, const QString& scriptName);
+
+    /*@jsdoc
+     * Triggered when the script generates a warning or {@link console.warn} is called.
+     * @function Script.warningMessage
+     * @param {string} message - The warning message.
+     * @param {string} scriptName - The name of the script that generated the warning message.
+     * @returns {Signal}
+     */
+    void warningMessage(const QString& message, const QString& scriptName);
+
+    /*@jsdoc
+     * Triggered when the script generates an information message or {@link console.info} is called.
+     * @function Script.infoMessage
+     * @param {string} message - The information message.
+     * @param {string} scriptName - The name of the script that generated the information message.
+     * @returns {Signal}
+     */
+    void infoMessage(const QString& message, const QString& scriptName);
+
+    /*@jsdoc
+     * Triggered when the running state of the script changes, e.g., from running to stopping.
+     * @function Script.runningStateChanged
+     * @returns {Signal}
+     */
+    void runningStateChanged();
+
+    /*@jsdoc
+     * @function Script.clearDebugWindow
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void clearDebugWindow();
+
+    /*@jsdoc
+     * @function Script.loadScript
+     * @param {string} scriptName - Script name.
+     * @param {boolean} isUserLoaded - Is user loaded.
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void loadScript(const QString& scriptName, bool isUserLoaded);
+
+    /*@jsdoc
+     * @function Script.reloadScript
+     * @param {string} scriptName - Script name.
+     * @param {boolean} isUserLoaded - Is user loaded.
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    void reloadScript(const QString& scriptName, bool isUserLoaded);
+
+    /*@jsdoc
+     * Triggered when the script has stopped.
+     * @function Script.doneRunning
+     * @returns {Signal}
+     */
+    void doneRunning();
+
+    /*@jsdoc
+     * @function Script.entityScriptDetailsUpdated
+     * @returns {Signal}
+     * @deprecated This signal is deprecated and will be removed.
+     */
+    // Emitted when an entity script is added or removed, or when the status of an entity
+    // script is updated (goes from RUNNING to ERROR_RUNNING_SCRIPT, for example)
+    void entityScriptDetailsUpdated();
+
+    /*@jsdoc
+     * Triggered when the script starts for the user. See also, {@link Entities.preload}.
+     * <p class="availableIn"><strong>Supported Script Types:</strong> Client Entity Scripts &bull; Server Entity Scripts</p>
+     * @function Script.entityScriptPreloadFinished
+     * @param {Uuid} entityID - The ID of the entity that the script is running in.
+     * @returns {Signal}
+     * @example <caption>Get the ID of the entity that a client entity script is running in.</caption>
+     * var entityScript = function () {
+     *     this.entityID = Uuid.NULL;
+     * };
+     *
+     * Script.entityScriptPreloadFinished.connect(function (entityID) {
+     *     this.entityID = entityID;
+     *     print("Entity ID: " + this.entityID);
+     * });
+     *
+     * var entityID = Entities.addEntity({
+     *     type: "Box",
+     *     position: Vec3.sum(MyAvatar.position, Vec3.multiplyQbyV(MyAvatar.orientation, { x: 0, y: 0, z: -5 })),
+     *     dimensions: { x: 0.5, y: 0.5, z: 0.5 },
+     *     color: { red: 255, green: 0, blue: 0 },
+     *     script: "(" + entityScript + ")",  // Could host the script on a Web server instead.
+     *     lifetime: 300  // Delete after 5 minutes.
+     * });
+     */
+    // Emitted when an entity script has finished running preload
+    void entityScriptPreloadFinished(const EntityItemID& entityID);
+
+    /*@jsdoc
+     * Triggered when a script generates an unhandled exception.
+     * @function Script.unhandledException
+     * @param {object} exception - The details of the exception.
+     * @returns {Signal}
+     * @example <caption>Report the details of an unhandled exception.</caption>
+     * Script.unhandledException.connect(function (exception) {
+     *     print("Unhandled exception: " + JSON.stringify(exception));
+     * });
+     * var properties = JSON.parse("{ x: 1"); // Invalid JSON string.
+     */
+    void unhandledException(const ScriptValue& exception);
+
+    // Triggered once before the first call to Script.addEventHandler happens on this ScriptManager
+    // connections assumed to use Qt::DirectConnection; not for use by scripts
+    void attachDefaultEventHandlers();
+
+    // Triggered repeatedly in the scripting loop to ensure entity edit messages get processed properly
+    // connections assumed to use Qt::DirectConnection; not for use by scripts
+    void releaseEntityPacketSenderMessages(bool wait);
+
+protected:
+    void init();
+
+    /*@jsdoc
+     * @function Script.executeOnScriptThread
+     * @param {function} function - Function.
+     * @param {ConnectionType} [type=2] - Connection type.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void executeOnScriptThread(std::function<void()> function, const Qt::ConnectionType& type = Qt::QueuedConnection );
+
+    /*@jsdoc
+     * @function Script._requireResolve
+     * @param {string} module - Module.
+     * @param {string} [relativeTo=""] - Relative to.
+     * @returns {string} Result.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    // note: this is not meant to be called directly, but just to have QMetaObject take care of wiring it up in general;
+    //   then inside of init() we just have to do "Script.require.resolve = Script._requireResolve;"
+    Q_INVOKABLE QString _requireResolve(const QString& moduleId, const QString& relativeTo = QString());
+
+    QString logException(const ScriptValue& exception);
+    void timerFired();
+    void stopAllTimers();
+    void stopAllTimersForEntityScript(const EntityItemID& entityID);
+    void refreshFileScript(const EntityItemID& entityID);
+    void updateEntityScriptStatus(const EntityItemID& entityID, const EntityScriptStatus& status, const QString& errorInfo = QString());
+    void setEntityScriptDetails(const EntityItemID& entityID, const EntityScriptDetails& details);
+    void setParentURL(const QString& parentURL) { _parentURL = parentURL; }
+
+    QTimer* setupTimerWithInterval(const ScriptValue& function, int intervalMS, bool isSingleShot);
+    void stopTimer(QTimer* timer);
+
+    QHash<EntityItemID, RegisteredEventHandlers> _registeredHandlers;
+
+    /*@jsdoc
+     * @function Script.entityScriptContentAvailable
+     * @param {Uuid} entityID - Entity ID.
+     * @param {string} scriptOrURL - Path.
+     * @param {string} contents - Contents.
+     * @param {boolean} isURL - Is a URL.
+     * @param {boolean} success - Success.
+     * @param {string} status - Status.
+     * @deprecated This function is deprecated and will be removed.
+     */
+    Q_INVOKABLE void entityScriptContentAvailable(const EntityItemID& entityID, const QString& scriptOrURL, const QString& contents, bool isURL, bool success, const QString& status);
+
+    EntityItemID currentEntityIdentifier; // Contains the defining entity script entity id during execution, if any. Empty for interface script execution.
+    QUrl currentSandboxURL; // The toplevel url string for the entity script that loaded the code being executed, else empty.
+    void doWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, std::function<void()> operation);
+    void callWithEnvironment(const EntityItemID& entityID, const QUrl& sandboxURL, const ScriptValue& function, const ScriptValue& thisObject, const ScriptValueList& args);
+
+    Context _context;
+    Type _type;
+    ScriptEnginePointer _engine;
+    QString _scriptContents;
+    QString _parentURL;
+    std::atomic<bool> _isFinished { false };
+    std::atomic<bool> _isRunning { false };
+    std::atomic<bool> _isStopping { false };
+    bool _isInitialized { false };
+    QHash<QTimer*, CallbackData> _timerFunctionMap;
+    QSet<QUrl> _includedURLs;
+    mutable QReadWriteLock _entityScriptsLock { QReadWriteLock::Recursive };
+    QHash<EntityItemID, EntityScriptDetails> _entityScripts;
+    EntityScriptContentAvailableMap _contentAvailableQueue;
+
+    bool _isThreaded { false };
+    qint64 _lastUpdate;
+
+    QString _fileNameString;
+    Quat _quatLibrary;
+    Vec3 _vec3Library;
+    Mat4 _mat4Library;
+    ScriptUUID _uuidLibrary;
+    ConsoleScriptingInterface _consoleScriptingInterface;
+    std::atomic<bool> _isUserLoaded { false };
+    bool _isReloading { false };
+
+    std::atomic<bool> _quitWhenFinished;
+
+    AssetScriptingInterface* _assetScriptingInterface;
+
+    std::function<bool()> _emitScriptUpdates{ []() { return true; }  };
+
+    std::recursive_mutex _lock;
+
+    std::chrono::microseconds _totalTimerExecution { 0 };
+
+    static const QString _SETTINGS_ENABLE_EXTENDED_EXCEPTIONS;
+
+    Setting::Handle<bool> _enableExtendedJSExceptions { _SETTINGS_ENABLE_EXTENDED_EXCEPTIONS, true };
+
+    QWeakPointer<ScriptEngines> _scriptEngines;
+
+    friend ScriptManagerPointer newScriptManager(Context context, const QString& scriptContents, const QString& fileNameString);
+};
+
+ScriptManagerPointer newScriptManager(ScriptManager::Context context,
+                                      const QString& scriptContents,
+                                      const QString& fileNameString);
+ScriptManagerPointer scriptManagerFactory(ScriptManager::Context context,
+                                        const QString& scriptContents,
+                                        const QString& fileNameString);
+
+#endif // hifi_ScriptManager_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptProgram.h b/libraries/script-engine/src/ScriptProgram.h
new file mode 100644
index 00000000000..ae26abace66
--- /dev/null
+++ b/libraries/script-engine/src/ScriptProgram.h
@@ -0,0 +1,58 @@
+//
+//  ScriptProgram.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/2/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptProgram_h
+#define hifi_ScriptProgram_h
+
+#include <memory>
+
+class ScriptProgram;
+class ScriptSyntaxCheckResult;
+using ScriptProgramPointer = std::shared_ptr<ScriptProgram>;
+using ScriptSyntaxCheckResultPointer = std::shared_ptr<ScriptSyntaxCheckResult>;
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptProgram
+class ScriptProgram {
+public:
+    virtual ScriptSyntaxCheckResultPointer checkSyntax() const = 0;
+    virtual QString fileName() const = 0;
+    virtual QString sourceCode() const = 0;
+
+protected:
+    ~ScriptProgram() {}  // prevent explicit deletion of base class
+};
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptSyntaxCheckResult
+class ScriptSyntaxCheckResult {
+public:
+    enum State
+    {
+        Error = 0,
+        Intermediate = 1,
+        Valid = 2
+    };
+
+public:
+    virtual int errorColumnNumber() const = 0;
+    virtual int errorLineNumber() const = 0;
+    virtual QString errorMessage() const = 0;
+    virtual State state() const = 0;
+
+protected:
+    ~ScriptSyntaxCheckResult() {}  // prevent explicit deletion of base class
+};
+
+#endif // hifi_ScriptProgram_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptUUID.cpp b/libraries/script-engine/src/ScriptUUID.cpp
index f88803c87c3..b9661e31eda 100644
--- a/libraries/script-engine/src/ScriptUUID.cpp
+++ b/libraries/script-engine/src/ScriptUUID.cpp
@@ -17,6 +17,7 @@
 
 #include "ScriptEngineLogging.h"
 #include "ScriptEngine.h"
+#include "ScriptManager.h"
 
 QUuid ScriptUUID::fromString(const QString& s) {
     return QUuid(s);
@@ -42,7 +43,7 @@ void ScriptUUID::print(const QString& label, const QUuid& id) {
     QString message = QString("%1 %2").arg(qPrintable(label));
     message = message.arg(id.toString());
     qCDebug(scriptengine) << message;
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->print(message);
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->print(message);
     }
 }
diff --git a/libraries/script-engine/src/ScriptUUID.h b/libraries/script-engine/src/ScriptUUID.h
index 24edb91184b..7f30036d7a0 100644
--- a/libraries/script-engine/src/ScriptUUID.h
+++ b/libraries/script-engine/src/ScriptUUID.h
@@ -19,7 +19,8 @@
 
 #include <QUuid>
 #include <QObject>
-#include <QtScript/QScriptable>
+
+#include "Scriptable.h"
 
 /*@jsdoc
  * The <code>Uuid</code> API provides facilities for working with UUIDs.
@@ -36,7 +37,7 @@
  * @property {Uuid} NULL - The null UUID, <code>"{00000000-0000-0000-0000-000000000000}"</code>.
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Uuid.html">Uuid</a></code> scripting interface
-class ScriptUUID : public QObject, protected QScriptable {
+class ScriptUUID : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(QString NULL READ NULL_UUID CONSTANT) // String for use in scripts.
 
diff --git a/libraries/script-engine/src/ScriptValue.cpp b/libraries/script-engine/src/ScriptValue.cpp
new file mode 100644
index 00000000000..df9729e3ae9
--- /dev/null
+++ b/libraries/script-engine/src/ScriptValue.cpp
@@ -0,0 +1,236 @@
+//
+//  ScriptValue.cpp
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 9/2/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptValue.h"
+
+#include "ScriptEngineLogging.h"
+
+
+class ScriptValueProxyNull final : public ScriptValueProxy {
+public:
+    virtual void release() override;
+    virtual ScriptValueProxy* copy() const override;
+
+public:
+    virtual ScriptValue call(const ScriptValue& thisObject = ScriptValue(), const ScriptValueList& args = ScriptValueList()) override;
+    virtual ScriptValue call(const ScriptValue& thisObject, const ScriptValue& arguments) override;
+    virtual ScriptValue construct(const ScriptValueList& args = ScriptValueList()) override;
+    virtual ScriptValue construct(const ScriptValue& arguments) override;
+    virtual ScriptValue data() const override;
+    virtual ScriptEnginePointer engine() const override;
+    virtual bool equals(const ScriptValue& other) const override;
+    virtual bool isArray() const override;
+    virtual bool isBool() const override;
+    virtual bool isError() const override;
+    virtual bool isFunction() const override;
+    virtual bool isNumber() const override;
+    virtual bool isNull() const override;
+    virtual bool isObject() const override;
+    virtual bool isString() const override;
+    virtual bool isUndefined() const override;
+    virtual bool isValid() const override;
+    virtual bool isVariant() const override;
+    virtual ScriptValueIteratorPointer newIterator() const override;
+    virtual ScriptValue property(const QString& name,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const override;
+    virtual ScriptValue property(quint32 arrayIndex,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const override;
+    virtual void setData(const ScriptValue& val) override;
+    virtual void setProperty(const QString& name,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) override;
+    virtual void setProperty(quint32 arrayIndex,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) override;
+    virtual void setPrototype(const ScriptValue& prototype) override;
+    virtual bool strictlyEquals(const ScriptValue& other) const override;
+
+    virtual bool toBool() const override;
+    virtual qint32 toInt32() const override;
+    virtual double toInteger() const override;
+    virtual double toNumber() const override;
+    virtual QString toString() const override;
+    virtual quint16 toUInt16() const override;
+    virtual quint32 toUInt32() const override;
+    virtual QVariant toVariant() const override;
+    virtual QObject* toQObject() const override;
+};
+
+static ScriptValueProxyNull SCRIPT_VALUE_NULL;
+
+ScriptValue::ScriptValue() : _proxy(&SCRIPT_VALUE_NULL) {}
+
+void ScriptValueProxyNull::release() {
+    // do nothing, we're a singlet
+}
+
+ScriptValueProxy* ScriptValueProxyNull::copy() const {
+    // return ourselves, we're a singlet
+    return const_cast <ScriptValueProxyNull*>(this);
+}
+
+ScriptValue ScriptValueProxyNull::call(const ScriptValue& thisObject, const ScriptValueList& args) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::call made to empty value");
+    return ScriptValue();
+}
+
+ScriptValue ScriptValueProxyNull::call(const ScriptValue& thisObject, const ScriptValue& arguments) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::call made to empty value");
+    return ScriptValue();
+}
+
+ScriptValue ScriptValueProxyNull::construct(const ScriptValueList& args) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::construct called on empty value");
+    return ScriptValue();
+}
+
+ScriptValue ScriptValueProxyNull::construct(const ScriptValue& arguments) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::construct called on empty value");
+    return ScriptValue();
+}
+
+ScriptValue ScriptValueProxyNull::data() const {
+    return ScriptValue();
+}
+
+ScriptEnginePointer ScriptValueProxyNull::engine() const {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::engine called on empty value");
+    return ScriptEnginePointer();
+}
+
+bool ScriptValueProxyNull::equals(const ScriptValue& other) const {
+    return other.isUndefined();
+}
+
+bool ScriptValueProxyNull::isArray() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isBool() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isError() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isFunction() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isNumber() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isNull() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isObject() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isString() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isUndefined() const {
+    return true;
+}
+
+bool ScriptValueProxyNull::isValid() const {
+    return false;
+}
+
+bool ScriptValueProxyNull::isVariant() const {
+    return false;
+}
+
+ScriptValueIteratorPointer ScriptValueProxyNull::newIterator() const {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::newIterator called on empty value");
+    return ScriptValueIteratorPointer();
+}
+
+ScriptValue ScriptValueProxyNull::property(const QString& name, const ScriptValue::ResolveFlags& mode) const {
+    return ScriptValue();
+}
+
+ScriptValue ScriptValueProxyNull::property(quint32 arrayIndex, const ScriptValue::ResolveFlags& mode) const {
+    return ScriptValue();
+}
+
+void ScriptValueProxyNull::setData(const ScriptValue& val) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::setData called on empty value");
+}
+
+void ScriptValueProxyNull::setProperty(const QString& name,
+                         const ScriptValue& value, const ScriptValue::PropertyFlags& flags) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::setProperty called on empty value");
+}
+
+void ScriptValueProxyNull::setProperty(quint32 arrayIndex,
+                         const ScriptValue& value, const ScriptValue::PropertyFlags& flags) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::setProperty called on empty value");
+}
+
+void ScriptValueProxyNull::setPrototype(const ScriptValue& prototype) {
+    Q_ASSERT(false);
+    qCWarning(scriptengine_script, "ScriptValue::setPrototype called on empty value");
+}
+
+bool ScriptValueProxyNull::strictlyEquals(const ScriptValue& other) const {
+    return !other.isValid();
+}
+
+bool ScriptValueProxyNull::toBool() const {
+    return false;
+}
+
+qint32 ScriptValueProxyNull::toInt32() const {
+    return 0;
+}
+
+double ScriptValueProxyNull::toInteger() const {
+    return 0;
+}
+
+double ScriptValueProxyNull::toNumber() const {
+    return 0;
+}
+
+QString ScriptValueProxyNull::toString() const {
+    return QString();
+}
+
+quint16 ScriptValueProxyNull::toUInt16() const {
+    return 0;
+}
+
+quint32 ScriptValueProxyNull::toUInt32() const {
+    return 0;
+}
+
+QVariant ScriptValueProxyNull::toVariant() const {
+    return QVariant();
+}
+
+QObject* ScriptValueProxyNull::toQObject() const {
+    return nullptr;
+}
diff --git a/libraries/script-engine/src/ScriptValue.h b/libraries/script-engine/src/ScriptValue.h
new file mode 100644
index 00000000000..d5a057e0ad0
--- /dev/null
+++ b/libraries/script-engine/src/ScriptValue.h
@@ -0,0 +1,377 @@
+//
+//  ScriptValue.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 4/25/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptValue_h
+#define hifi_ScriptValue_h
+
+#include <memory>
+
+#include <QtCore/QObject>
+#include <QtCore/QFlags>
+#include <QtCore/QList>
+#include <QtCore/QString>
+#include <QtCore/QVariant>
+
+class ScriptEngine;
+class ScriptValue;
+class ScriptValueIterator;
+class ScriptValueProxy;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+using ScriptValueList = QList<ScriptValue>;
+using ScriptValueIteratorPointer = std::shared_ptr<ScriptValueIterator>;
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptValue
+class ScriptValue {
+public:
+    enum ResolveFlag
+    {
+        ResolveLocal = 0,
+        ResolvePrototype = 1,
+    };
+    using ResolveFlags = QFlags<ResolveFlag>;
+
+    enum PropertyFlag
+    {
+        ReadOnly = 0x00000001,
+        Undeletable = 0x00000002,
+        SkipInEnumeration = 0x00000004,
+        PropertyGetter = 0x00000008,
+        PropertySetter = 0x00000010,
+        KeepExistingFlags = 0x00000800,
+    };
+    Q_DECLARE_FLAGS(PropertyFlags, PropertyFlag);
+
+public:
+    ScriptValue();
+    inline ScriptValue(const ScriptValue& src);
+    inline ~ScriptValue();
+    inline ScriptValue(ScriptValueProxy* proxy) : _proxy(proxy) {}
+    inline ScriptValueProxy* ptr() const { return _proxy; }
+    inline ScriptValue& operator=(const ScriptValue& other);
+
+public:
+    inline ScriptValue call(const ScriptValue& thisObject = ScriptValue(),
+                                    const ScriptValueList& args = ScriptValueList()) const;
+    inline ScriptValue call(const ScriptValue& thisObject, const ScriptValue& arguments) const;
+    inline ScriptValue construct(const ScriptValueList& args = ScriptValueList()) const;
+    inline ScriptValue construct(const ScriptValue& arguments) const;
+    inline ScriptValue data() const;
+    inline ScriptEnginePointer engine() const;
+    inline bool equals(const ScriptValue& other) const;
+    inline bool isArray() const;
+    inline bool isBool() const;
+    inline bool isError() const;
+    inline bool isFunction() const;
+    inline bool isNumber() const;
+    inline bool isNull() const;
+    inline bool isObject() const;
+    inline bool isString() const;
+    inline bool isUndefined() const;
+    inline bool isValid() const;
+    inline bool isVariant() const;
+    inline ScriptValueIteratorPointer newIterator() const;
+    inline ScriptValue property(const QString& name, const ResolveFlags& mode = ResolvePrototype) const;
+    inline ScriptValue property(quint32 arrayIndex, const ResolveFlags& mode = ResolvePrototype) const;
+    inline void setData(const ScriptValue& val);
+    inline void setProperty(const QString& name,
+                             const ScriptValue& value,
+                             const PropertyFlags& flags = KeepExistingFlags);
+    inline void setProperty(quint32 arrayIndex,
+                             const ScriptValue& value,
+                             const PropertyFlags& flags = KeepExistingFlags);
+    template <typename TYP, class ScriptEnginePointer = ScriptEnginePointer>
+    inline void setProperty(const QString& name, const TYP& value,
+                             const PropertyFlags& flags = KeepExistingFlags);
+    template <typename TYP, class ScriptEnginePointer = ScriptEnginePointer>
+    inline void setProperty(quint32 arrayIndex, const TYP& value,
+                             const PropertyFlags& flags = KeepExistingFlags);
+    inline void setPrototype(const ScriptValue& prototype);
+    inline bool strictlyEquals(const ScriptValue& other) const;
+
+    inline bool toBool() const;
+    inline qint32 toInt32() const;
+    inline double toInteger() const;
+    inline double toNumber() const;
+    inline QString toString() const;
+    inline quint16 toUInt16() const;
+    inline quint32 toUInt32() const;
+    inline QVariant toVariant() const;
+    inline QObject* toQObject() const;
+
+protected:
+    ScriptValueProxy* _proxy;
+};
+Q_DECLARE_OPERATORS_FOR_FLAGS(ScriptValue::PropertyFlags);
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptValue
+class ScriptValueProxy {
+public:
+    virtual void release() = 0;
+    virtual ScriptValueProxy* copy() const = 0;
+
+public:
+    virtual ScriptValue call(const ScriptValue& thisObject = ScriptValue(),
+                             const ScriptValueList& args = ScriptValueList()) = 0;
+    virtual ScriptValue call(const ScriptValue& thisObject, const ScriptValue& arguments) = 0;
+    virtual ScriptValue construct(const ScriptValueList& args = ScriptValueList()) = 0;
+    virtual ScriptValue construct(const ScriptValue& arguments) = 0;
+    virtual ScriptValue data() const = 0;
+    virtual ScriptEnginePointer engine() const = 0;
+    virtual bool equals(const ScriptValue& other) const = 0;
+    virtual bool isArray() const = 0;
+    virtual bool isBool() const = 0;
+    virtual bool isError() const = 0;
+    virtual bool isFunction() const = 0;
+    virtual bool isNumber() const = 0;
+    virtual bool isNull() const = 0;
+    virtual bool isObject() const = 0;
+    virtual bool isString() const = 0;
+    virtual bool isUndefined() const = 0;
+    virtual bool isValid() const = 0;
+    virtual bool isVariant() const = 0;
+    virtual ScriptValueIteratorPointer newIterator() const = 0;
+    virtual ScriptValue property(const QString& name,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const = 0;
+    virtual ScriptValue property(quint32 arrayIndex,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const = 0;
+    virtual void setData(const ScriptValue& val) = 0;
+    virtual void setProperty(const QString& name,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) = 0;
+    virtual void setProperty(quint32 arrayIndex,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) = 0;
+    virtual void setPrototype(const ScriptValue& prototype) = 0;
+    virtual bool strictlyEquals(const ScriptValue& other) const = 0;
+
+    virtual bool toBool() const = 0;
+    virtual qint32 toInt32() const = 0;
+    virtual double toInteger() const = 0;
+    virtual double toNumber() const = 0;
+    virtual QString toString() const = 0;
+    virtual quint16 toUInt16() const = 0;
+    virtual quint32 toUInt32() const = 0;
+    virtual QVariant toVariant() const = 0;
+    virtual QObject* toQObject() const = 0;
+
+protected:
+    ~ScriptValueProxy() {}  // prevent explicit deletion of base class
+};
+
+// the second template parameter is used to defer evaluation of calls to the engine until ScriptEngine isn't forward-declared
+template <typename TYP, class ScriptEnginePointer>
+void ScriptValue::setProperty(const QString& name, const TYP& value, const PropertyFlags& flags) {
+    setProperty(name, static_cast<const ScriptEnginePointer&>(engine())->newValue(value), flags);
+}
+
+// the second template parameter is used to defer evaluation of calls to the engine until ScriptEngine isn't forward-declared
+template <typename TYP, class ScriptEnginePointer>
+void ScriptValue::setProperty(quint32 arrayIndex, const TYP& value, const PropertyFlags& flags) {
+    setProperty(arrayIndex, static_cast<const ScriptEnginePointer&>(engine())->newValue(value), flags);
+}
+
+ScriptValue::ScriptValue(const ScriptValue& src) : _proxy(src.ptr()->copy()) {
+    Q_ASSERT(_proxy != nullptr);
+}
+
+ScriptValue::~ScriptValue() {
+    Q_ASSERT(_proxy != nullptr);
+    _proxy->release();
+}
+
+ScriptValue& ScriptValue::operator=(const ScriptValue& other) {
+    Q_ASSERT(_proxy != nullptr);
+    _proxy->release();
+    _proxy = other.ptr()->copy();
+    return *this;
+}
+
+ScriptValue ScriptValue::call(const ScriptValue& thisObject, const ScriptValueList& args) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->call(thisObject, args);
+}
+
+ScriptValue ScriptValue::call(const ScriptValue& thisObject, const ScriptValue& arguments) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->call(thisObject, arguments);
+}
+
+ScriptValue ScriptValue::construct(const ScriptValueList& args) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->construct(args);
+}
+
+ScriptValue ScriptValue::construct(const ScriptValue& arguments) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->construct(arguments);
+}
+
+ScriptValue ScriptValue::data() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->data();
+}
+
+ScriptEnginePointer ScriptValue::engine() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->engine();
+}
+
+bool ScriptValue::equals(const ScriptValue& other) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->equals(other);
+}
+
+bool ScriptValue::isArray() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isArray();
+}
+
+bool ScriptValue::isBool() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isBool();
+}
+
+bool ScriptValue::isError() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isError();
+}
+
+bool ScriptValue::isFunction() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isFunction();
+}
+
+bool ScriptValue::isNumber() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isNumber();
+}
+
+bool ScriptValue::isNull() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isNull();
+}
+
+bool ScriptValue::isObject() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isObject();
+}
+
+bool ScriptValue::isString() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isString();
+}
+
+bool ScriptValue::isUndefined() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isUndefined();
+}
+
+bool ScriptValue::isValid() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isValid();
+}
+
+bool ScriptValue::isVariant() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->isVariant();
+}
+
+ScriptValueIteratorPointer ScriptValue::newIterator() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->newIterator();
+}
+
+ScriptValue ScriptValue::property(const QString& name, const ResolveFlags& mode) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->property(name, mode);
+}
+
+ScriptValue ScriptValue::property(quint32 arrayIndex, const ResolveFlags& mode) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->property(arrayIndex, mode);
+}
+
+void ScriptValue::setData(const ScriptValue& val) {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->setData(val);
+}
+
+void ScriptValue::setProperty(const QString& name, const ScriptValue& value, const PropertyFlags& flags) {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->setProperty(name, value, flags);
+}
+
+void ScriptValue::setProperty(quint32 arrayIndex, const ScriptValue& value, const PropertyFlags& flags) {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->setProperty(arrayIndex, value, flags);
+}
+
+void ScriptValue::setPrototype(const ScriptValue& prototype) {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->setPrototype(prototype);
+}
+
+bool ScriptValue::strictlyEquals(const ScriptValue& other) const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->strictlyEquals(other);
+}
+
+bool ScriptValue::toBool() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toBool();
+}
+
+qint32 ScriptValue::toInt32() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toInt32();
+}
+
+double ScriptValue::toInteger() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toInteger();
+}
+
+double ScriptValue::toNumber() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toNumber();
+}
+
+QString ScriptValue::toString() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toString();
+}
+
+quint16 ScriptValue::toUInt16() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toUInt16();
+}
+
+quint32 ScriptValue::toUInt32() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toUInt32();
+}
+
+QVariant ScriptValue::toVariant() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toVariant();
+}
+
+QObject* ScriptValue::toQObject() const {
+    Q_ASSERT(_proxy != nullptr);
+    return _proxy->toQObject();
+}
+
+#endif // hifi_ScriptValue_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptValueIterator.h b/libraries/script-engine/src/ScriptValueIterator.h
new file mode 100644
index 00000000000..657bef6fbbf
--- /dev/null
+++ b/libraries/script-engine/src/ScriptValueIterator.h
@@ -0,0 +1,42 @@
+//
+//  ScriptValueIterator.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/2/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptValueIterator_h
+#define hifi_ScriptValueIterator_h
+
+#include <memory>
+
+#include <QtCore/QString>
+
+#include "ScriptValue.h"
+
+class ScriptValueIterator;
+using ScriptValueIteratorPointer = std::shared_ptr<ScriptValueIterator>;
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptValueIterator
+class ScriptValueIterator {
+public:
+    virtual ScriptValue::PropertyFlags flags() const = 0;
+    virtual bool hasNext() const = 0;
+    virtual QString name() const = 0;
+    virtual void next() = 0;
+    virtual ScriptValue value() const = 0;
+
+protected:
+    ~ScriptValueIterator() {}  // prevent explicit deletion of base class
+};
+
+#endif  // hifi_ScriptValueIterator_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptValueUtils.cpp b/libraries/script-engine/src/ScriptValueUtils.cpp
new file mode 100644
index 00000000000..da54182a9dc
--- /dev/null
+++ b/libraries/script-engine/src/ScriptValueUtils.cpp
@@ -0,0 +1,938 @@
+//
+//  ScriptValueUtils.cpp
+//  libraries/shared/src
+//
+//  Created by Anthony Thibault on 4/15/16.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Utilities for working with QtScriptValues
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptValueUtils.h"
+
+#include <QtCore/QVariant>
+#include <QtGui/QColor>
+#include <QtCore/QRect>
+#include <QtCore/QUrl>
+#include <QtCore/QUuid>
+
+#include <AACube.h>
+#include <shared/MiniPromises.h>
+#include <RegisteredMetaTypes.h>
+#include <EntityItemID.h>
+
+#include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "ScriptValueIterator.h"
+
+bool isListOfStrings(const ScriptValue& arg) {
+    if (!arg.isArray()) {
+        return false;
+    }
+
+    auto lengthProperty = arg.property("length");
+    if (!lengthProperty.isNumber()) {
+        return false;
+    }
+
+    int length = lengthProperty.toInt32();
+    for (int i = 0; i < length; i++) {
+        if (!arg.property(i).isString()) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+void registerMetaTypes(ScriptEngine* engine) {
+    scriptRegisterMetaType(engine, vec2ToScriptValue, vec2FromScriptValue);
+    scriptRegisterMetaType(engine, vec3ToScriptValue, vec3FromScriptValue);
+    scriptRegisterMetaType(engine, u8vec3ToScriptValue, u8vec3FromScriptValue);
+    scriptRegisterMetaType(engine, vec4toScriptValue, vec4FromScriptValue);
+    scriptRegisterMetaType(engine, quatToScriptValue, quatFromScriptValue);
+    scriptRegisterMetaType(engine, mat4toScriptValue, mat4FromScriptValue);
+
+    scriptRegisterMetaType(engine, qVectorVec3ToScriptValue, qVectorVec3FromScriptValue);
+    scriptRegisterMetaType(engine, qVectorQuatToScriptValue, qVectorQuatFromScriptValue);
+    scriptRegisterMetaType(engine, qVectorBoolToScriptValue, qVectorBoolFromScriptValue);
+    scriptRegisterMetaType(engine, qVectorFloatToScriptValue, qVectorFloatFromScriptValue);
+    scriptRegisterMetaType(engine, qVectorIntToScriptValue, qVectorIntFromScriptValue);
+    scriptRegisterMetaType(engine, qVectorQUuidToScriptValue, qVectorQUuidFromScriptValue);
+
+    scriptRegisterMetaType(engine, qSizeFToScriptValue, qSizeFFromScriptValue);
+    scriptRegisterMetaType(engine, qRectToScriptValue, qRectFromScriptValue);
+    scriptRegisterMetaType(engine, qURLToScriptValue, qURLFromScriptValue);
+    scriptRegisterMetaType(engine, qColorToScriptValue, qColorFromScriptValue);
+
+    scriptRegisterMetaType(engine, pickRayToScriptValue, pickRayFromScriptValue);
+    scriptRegisterMetaType(engine, collisionToScriptValue, collisionFromScriptValue);
+    scriptRegisterMetaType(engine, quuidToScriptValue, quuidFromScriptValue);
+    scriptRegisterMetaType(engine, aaCubeToScriptValue, aaCubeFromScriptValue);
+
+    scriptRegisterMetaType(engine, stencilMaskModeToScriptValue, stencilMaskModeFromScriptValue);
+
+    scriptRegisterMetaType(engine, promiseToScriptValue, promiseFromScriptValue);
+
+    scriptRegisterSequenceMetaType<QVector<unsigned int>>(engine);
+}
+
+ScriptValue vec2ToScriptValue(ScriptEngine* engine, const glm::vec2& vec2) {
+    auto prototype = engine->globalObject().property("__hifi_vec2__");
+    if (!prototype.property("defined").toBool()) {
+        prototype = engine->evaluate(
+            "__hifi_vec2__ = Object.defineProperties({}, { "
+            "defined: { value: true },"
+            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "u: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "v: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } }"
+            "})");
+    }
+    ScriptValue value = engine->newObject();
+    value.setProperty("x", vec2.x);
+    value.setProperty("y", vec2.y);
+    value.setPrototype(prototype);
+    return value;
+}
+
+bool vec2FromScriptValue(const ScriptValue& object, glm::vec2& vec2) {
+    if (object.isNumber()) {
+        vec2 = glm::vec2(object.toVariant().toFloat());
+    } else if (object.isArray()) {
+        QVariantList list = object.toVariant().toList();
+        if (list.length() == 2) {
+            vec2.x = list[0].toFloat();
+            vec2.y = list[1].toFloat();
+        }
+    } else {
+        ScriptValue x = object.property("x");
+        if (!x.isValid()) {
+            x = object.property("u");
+        }
+
+        ScriptValue y = object.property("y");
+        if (!y.isValid()) {
+            y = object.property("v");
+        }
+
+        vec2.x = x.toVariant().toFloat();
+        vec2.y = y.toVariant().toFloat();
+    }
+    return true;
+}
+
+ScriptValue vec3ToScriptValue(ScriptEngine* engine, const glm::vec3& vec3) {
+    auto prototype = engine->globalObject().property("__hifi_vec3__");
+    if (!prototype.property("defined").toBool()) {
+        prototype = engine->evaluate(
+            "__hifi_vec3__ = Object.defineProperties({}, { "
+            "defined: { value: true },"
+            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "2: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
+            "r: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "g: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "b: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
+            "red: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "green: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "blue: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } }"
+            "})");
+    }
+    ScriptValue value = engine->newObject();
+    value.setProperty("x", vec3.x);
+    value.setProperty("y", vec3.y);
+    value.setProperty("z", vec3.z);
+    value.setPrototype(prototype);
+    return value;
+}
+
+ScriptValue vec3ColorToScriptValue(ScriptEngine* engine, const glm::vec3& vec3) {
+    auto prototype = engine->globalObject().property("__hifi_vec3_color__");
+    if (!prototype.property("defined").toBool()) {
+        prototype = engine->evaluate(
+            "__hifi_vec3_color__ = Object.defineProperties({}, { "
+            "defined: { value: true },"
+            "0: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "1: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "2: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
+            "r: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "g: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "b: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
+            "x: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "y: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "z: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } }"
+            "})");
+    }
+    ScriptValue value = engine->newObject();
+    value.setProperty("red", vec3.x);
+    value.setProperty("green", vec3.y);
+    value.setProperty("blue", vec3.z);
+    value.setPrototype(prototype);
+    return value;
+}
+
+bool vec3FromScriptValue(const ScriptValue& object, glm::vec3& vec3) {
+    if (object.isNumber()) {
+        vec3 = glm::vec3(object.toVariant().toFloat());
+    } else if (object.isString()) {
+        QColor qColor(object.toString());
+        if (qColor.isValid()) {
+            vec3.x = qColor.red();
+            vec3.y = qColor.green();
+            vec3.z = qColor.blue();
+        }
+    } else if (object.isArray()) {
+        QVariantList list = object.toVariant().toList();
+        if (list.length() == 3) {
+            vec3.x = list[0].toFloat();
+            vec3.y = list[1].toFloat();
+            vec3.z = list[2].toFloat();
+        }
+    } else {
+        ScriptValue x = object.property("x");
+        if (!x.isValid()) {
+            x = object.property("r");
+        }
+        if (!x.isValid()) {
+            x = object.property("red");
+        }
+
+        ScriptValue y = object.property("y");
+        if (!y.isValid()) {
+            y = object.property("g");
+        }
+        if (!y.isValid()) {
+            y = object.property("green");
+        }
+
+        ScriptValue z = object.property("z");
+        if (!z.isValid()) {
+            z = object.property("b");
+        }
+        if (!z.isValid()) {
+            z = object.property("blue");
+        }
+
+        vec3.x = x.toVariant().toFloat();
+        vec3.y = y.toVariant().toFloat();
+        vec3.z = z.toVariant().toFloat();
+    }
+    return true;
+}
+
+ScriptValue u8vec3ToScriptValue(ScriptEngine* engine, const glm::u8vec3& vec3) {
+    auto prototype = engine->globalObject().property("__hifi_u8vec3__");
+    if (!prototype.property("defined").toBool()) {
+        prototype = engine->evaluate(
+            "__hifi_u8vec3__ = Object.defineProperties({}, { "
+            "defined: { value: true },"
+            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "2: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
+            "r: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "g: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "b: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
+            "red: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
+            "green: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
+            "blue: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } }"
+            "})");
+    }
+    ScriptValue value = engine->newObject();
+    value.setProperty("x", vec3.x);
+    value.setProperty("y", vec3.y);
+    value.setProperty("z", vec3.z);
+    value.setPrototype(prototype);
+    return value;
+}
+
+ScriptValue u8vec3ColorToScriptValue(ScriptEngine* engine, const glm::u8vec3& vec3) {
+    auto prototype = engine->globalObject().property("__hifi_u8vec3_color__");
+    if (!prototype.property("defined").toBool()) {
+        prototype = engine->evaluate(
+            "__hifi_u8vec3_color__ = Object.defineProperties({}, { "
+            "defined: { value: true },"
+            "0: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "1: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "2: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
+            "r: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "g: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "b: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
+            "x: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
+            "y: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
+            "z: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } }"
+            "})");
+    }
+    ScriptValue value = engine->newObject();
+    value.setProperty("red", vec3.x);
+    value.setProperty("green", vec3.y);
+    value.setProperty("blue", vec3.z);
+    value.setPrototype(prototype);
+    return value;
+}
+
+bool u8vec3FromScriptValue(const ScriptValue& object, glm::u8vec3& vec3) {
+    if (object.isNumber()) {
+        vec3 = glm::vec3(object.toVariant().toUInt());
+    } else if (object.isString()) {
+        QColor qColor(object.toString());
+        if (qColor.isValid()) {
+            vec3.x = (uint8_t)qColor.red();
+            vec3.y = (uint8_t)qColor.green();
+            vec3.z = (uint8_t)qColor.blue();
+        }
+    } else if (object.isArray()) {
+        QVariantList list = object.toVariant().toList();
+        if (list.length() == 3) {
+            vec3.x = list[0].toUInt();
+            vec3.y = list[1].toUInt();
+            vec3.z = list[2].toUInt();
+        }
+    } else {
+        ScriptValue x = object.property("x");
+        if (!x.isValid()) {
+            x = object.property("r");
+        }
+        if (!x.isValid()) {
+            x = object.property("red");
+        }
+
+        ScriptValue y = object.property("y");
+        if (!y.isValid()) {
+            y = object.property("g");
+        }
+        if (!y.isValid()) {
+            y = object.property("green");
+        }
+
+        ScriptValue z = object.property("z");
+        if (!z.isValid()) {
+            z = object.property("b");
+        }
+        if (!z.isValid()) {
+            z = object.property("blue");
+        }
+
+        vec3.x = x.toVariant().toUInt();
+        vec3.y = y.toVariant().toUInt();
+        vec3.z = z.toVariant().toUInt();
+    }
+    return true;
+}
+
+ScriptValue vec4toScriptValue(ScriptEngine* engine, const glm::vec4& vec4) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("x", vec4.x);
+    obj.setProperty("y", vec4.y);
+    obj.setProperty("z", vec4.z);
+    obj.setProperty("w", vec4.w);
+    return obj;
+}
+
+bool vec4FromScriptValue(const ScriptValue& object, glm::vec4& vec4) {
+    vec4.x = object.property("x").toVariant().toFloat();
+    vec4.y = object.property("y").toVariant().toFloat();
+    vec4.z = object.property("z").toVariant().toFloat();
+    vec4.w = object.property("w").toVariant().toFloat();
+    return true;
+}
+
+ScriptValue mat4toScriptValue(ScriptEngine* engine, const glm::mat4& mat4) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("r0c0", mat4[0][0]);
+    obj.setProperty("r1c0", mat4[0][1]);
+    obj.setProperty("r2c0", mat4[0][2]);
+    obj.setProperty("r3c0", mat4[0][3]);
+    obj.setProperty("r0c1", mat4[1][0]);
+    obj.setProperty("r1c1", mat4[1][1]);
+    obj.setProperty("r2c1", mat4[1][2]);
+    obj.setProperty("r3c1", mat4[1][3]);
+    obj.setProperty("r0c2", mat4[2][0]);
+    obj.setProperty("r1c2", mat4[2][1]);
+    obj.setProperty("r2c2", mat4[2][2]);
+    obj.setProperty("r3c2", mat4[2][3]);
+    obj.setProperty("r0c3", mat4[3][0]);
+    obj.setProperty("r1c3", mat4[3][1]);
+    obj.setProperty("r2c3", mat4[3][2]);
+    obj.setProperty("r3c3", mat4[3][3]);
+    return obj;
+}
+
+bool mat4FromScriptValue(const ScriptValue& object, glm::mat4& mat4) {
+    mat4[0][0] = object.property("r0c0").toVariant().toFloat();
+    mat4[0][1] = object.property("r1c0").toVariant().toFloat();
+    mat4[0][2] = object.property("r2c0").toVariant().toFloat();
+    mat4[0][3] = object.property("r3c0").toVariant().toFloat();
+    mat4[1][0] = object.property("r0c1").toVariant().toFloat();
+    mat4[1][1] = object.property("r1c1").toVariant().toFloat();
+    mat4[1][2] = object.property("r2c1").toVariant().toFloat();
+    mat4[1][3] = object.property("r3c1").toVariant().toFloat();
+    mat4[2][0] = object.property("r0c2").toVariant().toFloat();
+    mat4[2][1] = object.property("r1c2").toVariant().toFloat();
+    mat4[2][2] = object.property("r2c2").toVariant().toFloat();
+    mat4[2][3] = object.property("r3c2").toVariant().toFloat();
+    mat4[3][0] = object.property("r0c3").toVariant().toFloat();
+    mat4[3][1] = object.property("r1c3").toVariant().toFloat();
+    mat4[3][2] = object.property("r2c3").toVariant().toFloat();
+    mat4[3][3] = object.property("r3c3").toVariant().toFloat();
+    return true;
+}
+
+ScriptValue qVectorVec3ColorToScriptValue(ScriptEngine* engine, const QVector<glm::vec3>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, vec3ColorToScriptValue(engine, vector.at(i)));
+    }
+    return array;
+}
+
+ScriptValue qVectorVec3ToScriptValue(ScriptEngine* engine, const QVector<glm::vec3>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, vec3ToScriptValue(engine, vector.at(i)));
+    }
+    return array;
+}
+
+QVector<glm::vec3> qVectorVec3FromScriptValue(const ScriptValue& array) {
+    QVector<glm::vec3> newVector;
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        glm::vec3 newVec3 = glm::vec3();
+        vec3FromScriptValue(array.property(i), newVec3);
+        newVector << newVec3;
+    }
+    return newVector;
+}
+
+bool qVectorVec3FromScriptValue(const ScriptValue& array, QVector<glm::vec3>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        glm::vec3 newVec3 = glm::vec3();
+        vec3FromScriptValue(array.property(i), newVec3);
+        vector << newVec3;
+    }
+    return true;
+}
+
+ScriptValue quatToScriptValue(ScriptEngine* engine, const glm::quat& quat) {
+    ScriptValue obj = engine->newObject();
+    if (quat.x != quat.x || quat.y != quat.y || quat.z != quat.z || quat.w != quat.w) {
+        // if quat contains a NaN don't try to convert it
+        return obj;
+    }
+    obj.setProperty("x", quat.x);
+    obj.setProperty("y", quat.y);
+    obj.setProperty("z", quat.z);
+    obj.setProperty("w", quat.w);
+    return obj;
+}
+
+bool quatFromScriptValue(const ScriptValue& object, glm::quat& quat) {
+    quat.x = object.property("x").toVariant().toFloat();
+    quat.y = object.property("y").toVariant().toFloat();
+    quat.z = object.property("z").toVariant().toFloat();
+    quat.w = object.property("w").toVariant().toFloat();
+
+    // enforce normalized quaternion
+    float length = glm::length(quat);
+    if (length > FLT_EPSILON) {
+        quat /= length;
+    } else {
+        quat = glm::quat();
+    }
+    return true;
+}
+
+ScriptValue qVectorQuatToScriptValue(ScriptEngine* engine, const QVector<glm::quat>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, quatToScriptValue(engine, vector.at(i)));
+    }
+    return array;
+}
+
+ScriptValue qVectorBoolToScriptValue(ScriptEngine* engine, const QVector<bool>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, vector.at(i));
+    }
+    return array;
+}
+
+QVector<float> qVectorFloatFromScriptValue(const ScriptValue& array) {
+    if (!array.isArray()) {
+        return QVector<float>();
+    }
+    QVector<float> newVector;
+    int length = array.property("length").toInteger();
+    newVector.reserve(length);
+    for (int i = 0; i < length; i++) {
+        if (array.property(i).isNumber()) {
+            newVector << array.property(i).toNumber();
+        }
+    }
+
+    return newVector;
+}
+
+ScriptValue qVectorQUuidToScriptValue(ScriptEngine* engine, const QVector<QUuid>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, quuidToScriptValue(engine, vector.at(i)));
+    }
+    return array;
+}
+
+bool qVectorQUuidFromScriptValue(const ScriptValue& array, QVector<QUuid>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        vector << array.property(i).toVariant().toUuid();
+    }
+    return true;
+}
+
+QVector<QUuid> qVectorQUuidFromScriptValue(const ScriptValue& array) {
+    if (!array.isArray()) {
+        return QVector<QUuid>();
+    }
+    QVector<QUuid> newVector;
+    int length = array.property("length").toInteger();
+    newVector.reserve(length);
+    for (int i = 0; i < length; i++) {
+        QString uuidAsString = array.property(i).toString();
+        QUuid fromString(uuidAsString);
+        newVector << fromString;
+    }
+    return newVector;
+}
+
+ScriptValue qVectorFloatToScriptValue(ScriptEngine* engine, const QVector<float>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        float num = vector.at(i);
+        array.setProperty(i, engine->newValue(num));
+    }
+    return array;
+}
+
+ScriptValue qVectorIntToScriptValue(ScriptEngine* engine, const QVector<uint32_t>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        int num = vector.at(i);
+        array.setProperty(i, engine->newValue(num));
+    }
+    return array;
+}
+
+bool qVectorFloatFromScriptValue(const ScriptValue& array, QVector<float>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        vector << array.property(i).toVariant().toFloat();
+    }
+    return true;
+}
+
+bool qVectorIntFromScriptValue(const ScriptValue& array, QVector<uint32_t>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        vector << array.property(i).toVariant().toInt();
+    }
+    return true;
+}
+
+QVector<glm::quat> qVectorQuatFromScriptValue(const ScriptValue& array) {
+    QVector<glm::quat> newVector;
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        glm::quat newQuat = glm::quat();
+        quatFromScriptValue(array.property(i), newQuat);
+        newVector << newQuat;
+    }
+    return newVector;
+}
+
+bool qVectorQuatFromScriptValue(const ScriptValue& array, QVector<glm::quat>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        glm::quat newQuat = glm::quat();
+        quatFromScriptValue(array.property(i), newQuat);
+        vector << newQuat;
+    }
+    return true;
+}
+
+QVector<bool> qVectorBoolFromScriptValue(const ScriptValue& array) {
+    QVector<bool> newVector;
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        newVector << array.property(i).toBool();
+    }
+    return newVector;
+}
+
+bool qVectorBoolFromScriptValue(const ScriptValue& array, QVector<bool>& vector) {
+    int length = array.property("length").toInteger();
+
+    for (int i = 0; i < length; i++) {
+        vector << array.property(i).toBool();
+    }
+    return true;
+}
+
+ScriptValue qRectToScriptValue(ScriptEngine* engine, const QRect& rect) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("x", rect.x());
+    obj.setProperty("y", rect.y());
+    obj.setProperty("width", rect.width());
+    obj.setProperty("height", rect.height());
+    return obj;
+}
+
+bool qRectFromScriptValue(const ScriptValue& object, QRect& rect) {
+    rect.setX(object.property("x").toVariant().toInt());
+    rect.setY(object.property("y").toVariant().toInt());
+    rect.setWidth(object.property("width").toVariant().toInt());
+    rect.setHeight(object.property("height").toVariant().toInt());
+    return true;
+}
+
+ScriptValue qRectFToScriptValue(ScriptEngine* engine, const QRectF& rect) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("x", rect.x());
+    obj.setProperty("y", rect.y());
+    obj.setProperty("width", rect.width());
+    obj.setProperty("height", rect.height());
+    return obj;
+}
+
+bool qRectFFromScriptValue(const ScriptValue& object, QRectF& rect) {
+    rect.setX(object.property("x").toVariant().toFloat());
+    rect.setY(object.property("y").toVariant().toFloat());
+    rect.setWidth(object.property("width").toVariant().toFloat());
+    rect.setHeight(object.property("height").toVariant().toFloat());
+    return true;
+}
+
+ScriptValue qColorToScriptValue(ScriptEngine* engine, const QColor& color) {
+    ScriptValue object = engine->newObject();
+    object.setProperty("red", color.red());
+    object.setProperty("green", color.green());
+    object.setProperty("blue", color.blue());
+    object.setProperty("alpha", color.alpha());
+    return object;
+}
+
+/*@jsdoc
+ * An axis-aligned cube, defined as the bottom right near (minimum axes values) corner of the cube plus the dimension of its 
+ * sides.
+ * @typedef {object} AACube
+ * @property {number} x - X coordinate of the brn corner of the cube.
+ * @property {number} y - Y coordinate of the brn corner of the cube.
+ * @property {number} z - Z coordinate of the brn corner of the cube.
+ * @property {number} scale - The dimensions of each side of the cube.
+ */
+ScriptValue aaCubeToScriptValue(ScriptEngine* engine, const AACube& aaCube) {
+    ScriptValue obj = engine->newObject();
+    const glm::vec3& corner = aaCube.getCorner();
+    obj.setProperty("x", corner.x);
+    obj.setProperty("y", corner.y);
+    obj.setProperty("z", corner.z);
+    obj.setProperty("scale", aaCube.getScale());
+    return obj;
+}
+
+bool aaCubeFromScriptValue(const ScriptValue& object, AACube& aaCube) {
+    glm::vec3 corner;
+    corner.x = object.property("x").toVariant().toFloat();
+    corner.y = object.property("y").toVariant().toFloat();
+    corner.z = object.property("z").toVariant().toFloat();
+    float scale = object.property("scale").toVariant().toFloat();
+
+    aaCube.setBox(corner, scale);
+    return true;
+}
+
+bool qColorFromScriptValue(const ScriptValue& object, QColor& color) {
+    if (object.isNumber()) {
+        color.setRgb(object.toUInt32());
+
+    } else if (object.isString()) {
+        color.setNamedColor(object.toString());
+
+    } else {
+        ScriptValue alphaValue = object.property("alpha");
+        color.setRgb(object.property("red").toInt32(), object.property("green").toInt32(), object.property("blue").toInt32(),
+                     alphaValue.isNumber() ? alphaValue.toInt32() : 255);
+    }
+    return true;
+}
+
+ScriptValue qURLToScriptValue(ScriptEngine* engine, const QUrl& url) {
+    return engine->newValue(url.toString());
+}
+
+bool qURLFromScriptValue(const ScriptValue& object, QUrl& url) {
+    url = object.toString();
+    return true;
+}
+
+ScriptValue pickRayToScriptValue(ScriptEngine* engine, const PickRay& pickRay) {
+    ScriptValue obj = engine->newObject();
+    ScriptValue origin = vec3ToScriptValue(engine, pickRay.origin);
+    obj.setProperty("origin", origin);
+    ScriptValue direction = vec3ToScriptValue(engine, pickRay.direction);
+    obj.setProperty("direction", direction);
+    return obj;
+}
+
+bool pickRayFromScriptValue(const ScriptValue& object, PickRay& pickRay) {
+    ScriptValue originValue = object.property("origin");
+    if (originValue.isValid()) {
+        auto x = originValue.property("x");
+        auto y = originValue.property("y");
+        auto z = originValue.property("z");
+        if (x.isValid() && y.isValid() && z.isValid()) {
+            pickRay.origin.x = x.toVariant().toFloat();
+            pickRay.origin.y = y.toVariant().toFloat();
+            pickRay.origin.z = z.toVariant().toFloat();
+        }
+    }
+    ScriptValue directionValue = object.property("direction");
+    if (directionValue.isValid()) {
+        auto x = directionValue.property("x");
+        auto y = directionValue.property("y");
+        auto z = directionValue.property("z");
+        if (x.isValid() && y.isValid() && z.isValid()) {
+            pickRay.direction.x = x.toVariant().toFloat();
+            pickRay.direction.y = y.toVariant().toFloat();
+            pickRay.direction.z = z.toVariant().toFloat();
+        }
+    }
+    return true;
+}
+
+/*@jsdoc
+ * Details of a collision between avatars and entities.
+ * @typedef {object} Collision
+ * @property {ContactEventType} type - The contact type of the collision event.
+ * @property {Uuid} idA - The ID of one of the avatars or entities in the collision.
+ * @property {Uuid} idB - The ID of the other of the avatars or entities in the collision.
+ * @property {Vec3} penetration - The amount of penetration between the two items.
+ * @property {Vec3} contactPoint - The point of contact.
+ * @property {Vec3} velocityChange - The change in relative velocity of the two items, in m/s.
+ */
+ScriptValue collisionToScriptValue(ScriptEngine* engine, const Collision& collision) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("type", collision.type);
+    obj.setProperty("idA", quuidToScriptValue(engine, collision.idA));
+    obj.setProperty("idB", quuidToScriptValue(engine, collision.idB));
+    obj.setProperty("penetration", vec3ToScriptValue(engine, collision.penetration));
+    obj.setProperty("contactPoint", vec3ToScriptValue(engine, collision.contactPoint));
+    obj.setProperty("velocityChange", vec3ToScriptValue(engine, collision.velocityChange));
+    return obj;
+}
+
+bool collisionFromScriptValue(const ScriptValue& object, Collision& collision) {
+    // TODO: implement this when we know what it means to accept collision events from JS
+    return false;
+}
+
+ScriptValue quuidToScriptValue(ScriptEngine* engine, const QUuid& uuid) {
+    if (uuid.isNull()) {
+        return engine->nullValue();
+    }
+    ScriptValue obj(engine->newValue(uuid.toString()));
+    return obj;
+}
+
+bool quuidFromScriptValue(const ScriptValue& object, QUuid& uuid) {
+    if (object.isNull()) {
+        uuid = QUuid();
+        return true;
+    }
+    QString uuidAsString = object.toVariant().toString();
+    QUuid fromString(uuidAsString);
+    uuid = fromString;
+    return true;
+}
+
+/*@jsdoc
+ * A 2D size value.
+ * @typedef {object} Size
+ * @property {number} height - The height value.
+ * @property {number} width - The width value.
+ */
+ScriptValue qSizeFToScriptValue(ScriptEngine* engine, const QSizeF& qSizeF) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("width", qSizeF.width());
+    obj.setProperty("height", qSizeF.height());
+    return obj;
+}
+
+bool qSizeFFromScriptValue(const ScriptValue& object, QSizeF& qSizeF) {
+    qSizeF.setWidth(object.property("width").toVariant().toFloat());
+    qSizeF.setHeight(object.property("height").toVariant().toFloat());
+    return true;
+}
+
+/*@jsdoc
+ * The details of an animation that is playing.
+ * @typedef {object} Avatar.AnimationDetails
+ * @property {string} role - <em>Not used.</em>
+ * @property {string} url - The URL to the animation file. Animation files need to be in glTF or FBX format but only need to 
+ *     contain the avatar skeleton and animation data. glTF models may be in JSON or binary format (".gltf" or ".glb" URLs 
+ *     respectively).
+ *     <p><strong>Warning:</strong> glTF animations currently do not always animate correctly.</p>
+ * @property {number} fps - The frames per second(FPS) rate for the animation playback. 30 FPS is normal speed.
+ * @property {number} priority - <em>Not used.</em>
+ * @property {boolean} loop - <code>true</code> if the animation should loop, <code>false</code> if it shouldn't.
+ * @property {boolean} hold - <em>Not used.</em>
+ * @property {number} firstFrame - The frame the animation should start at.
+ * @property {number} lastFrame - The frame the animation should stop at.
+ * @property {boolean} running - <em>Not used.</em>
+ * @property {number} currentFrame - The current frame being played.
+ * @property {boolean} startAutomatically - <em>Not used.</em>
+ * @property {boolean} allowTranslation - <em>Not used.</em>
+ */
+ScriptValue animationDetailsToScriptValue(ScriptEngine* engine, const AnimationDetails& details) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("role", details.role);
+    obj.setProperty("url", details.url.toString());
+    obj.setProperty("fps", details.fps);
+    obj.setProperty("priority", details.priority);
+    obj.setProperty("loop", details.loop);
+    obj.setProperty("hold", details.hold);
+    obj.setProperty("startAutomatically", details.startAutomatically);
+    obj.setProperty("firstFrame", details.firstFrame);
+    obj.setProperty("lastFrame", details.lastFrame);
+    obj.setProperty("running", details.running);
+    obj.setProperty("currentFrame", details.currentFrame);
+    obj.setProperty("allowTranslation", details.allowTranslation);
+    return obj;
+}
+
+bool animationDetailsFromScriptValue(const ScriptValue& object, AnimationDetails& details) {
+    // nothing for now...
+    return false;
+}
+
+ScriptValue meshToScriptValue(ScriptEngine* engine, MeshProxy* const& in) {
+    return engine->newQObject(in, ScriptEngine::QtOwnership);
+}
+
+bool meshFromScriptValue(const ScriptValue& value, MeshProxy*& out) {
+    out = qobject_cast<MeshProxy*>(value.toQObject());
+    return true;
+}
+
+ScriptValue meshesToScriptValue(ScriptEngine* engine, const MeshProxyList& in) {
+    // ScriptValueList result;
+    ScriptValue result = engine->newArray();
+    int i = 0;
+    foreach (MeshProxy* const meshProxy, in) { result.setProperty(i++, meshToScriptValue(engine, meshProxy)); }
+    return result;
+}
+
+bool meshesFromScriptValue(const ScriptValue& value, MeshProxyList& out) {
+    ScriptValueIteratorPointer itr(value.newIterator());
+
+    qDebug() << "in meshesFromScriptValue, value.length =" << value.property("length").toInt32();
+
+    while (itr->hasNext()) {
+        itr->next();
+        MeshProxy* meshProxy = scriptvalue_cast<MeshProxyList::value_type>(itr->value());
+        if (meshProxy) {
+            out.append(meshProxy);
+        } else {
+            qDebug() << "null meshProxy";
+        }
+    }
+    return true;
+}
+
+/*@jsdoc
+ * A triangle in a mesh.
+ * @typedef {object} MeshFace
+ * @property {number[]} vertices - The indexes of the three vertices that make up the face.
+ */
+ScriptValue meshFaceToScriptValue(ScriptEngine* engine, const MeshFace& meshFace) {
+    ScriptValue obj = engine->newObject();
+    obj.setProperty("vertices", qVectorIntToScriptValue(engine, meshFace.vertexIndices));
+    return obj;
+}
+
+bool meshFaceFromScriptValue(const ScriptValue& object, MeshFace& meshFaceResult) {
+    return qVectorIntFromScriptValue(object.property("vertices"), meshFaceResult.vertexIndices);
+}
+
+ScriptValue qVectorMeshFaceToScriptValue(ScriptEngine* engine, const QVector<MeshFace>& vector) {
+    ScriptValue array = engine->newArray();
+    for (int i = 0; i < vector.size(); i++) {
+        array.setProperty(i, meshFaceToScriptValue(engine, vector.at(i)));
+    }
+    return array;
+}
+
+bool qVectorMeshFaceFromScriptValue(const ScriptValue& array, QVector<MeshFace>& result) {
+    int length = array.property("length").toInteger();
+    result.clear();
+
+    for (int i = 0; i < length; i++) {
+        MeshFace meshFace = MeshFace();
+        meshFaceFromScriptValue(array.property(i), meshFace);
+        result << meshFace;
+    }
+    return true;
+}
+
+ScriptValue stencilMaskModeToScriptValue(ScriptEngine* engine, const StencilMaskMode& stencilMode) {
+    return engine->newValue((int)stencilMode);
+}
+
+bool stencilMaskModeFromScriptValue(const ScriptValue& object, StencilMaskMode& stencilMode) {
+    stencilMode = StencilMaskMode(object.toVariant().toInt());
+    return true;
+}
+
+bool promiseFromScriptValue(const ScriptValue& object, std::shared_ptr<MiniPromise>& promise) {
+    Q_ASSERT(false);
+    return false;
+}
+ScriptValue promiseToScriptValue(ScriptEngine* engine, const std::shared_ptr<MiniPromise>& promise) {
+    return engine->newQObject(promise.get());
+}
+
+ScriptValue EntityItemIDtoScriptValue(ScriptEngine* engine, const EntityItemID& id) {
+    return quuidToScriptValue(engine, id);
+}
+
+bool EntityItemIDfromScriptValue(const ScriptValue& object, EntityItemID& id) {
+    return quuidFromScriptValue(object, id);
+}
+
+QVector<EntityItemID> qVectorEntityItemIDFromScriptValue(const ScriptValue& array) {
+    if (!array.isArray()) {
+        return QVector<EntityItemID>();
+    }
+    QVector<EntityItemID> newVector;
+    int length = array.property("length").toInteger();
+    newVector.reserve(length);
+    for (int i = 0; i < length; i++) {
+        QString uuidAsString = array.property(i).toString();
+        EntityItemID fromString(uuidAsString);
+        newVector << fromString;
+    }
+    return newVector;
+}
diff --git a/libraries/script-engine/src/ScriptValueUtils.h b/libraries/script-engine/src/ScriptValueUtils.h
new file mode 100644
index 00000000000..9773a0e58b8
--- /dev/null
+++ b/libraries/script-engine/src/ScriptValueUtils.h
@@ -0,0 +1,272 @@
+//
+//  ScriptValueUtils.h
+//  libraries/shared/src
+//
+//  Created by Anthony Thibault on 4/15/16.
+//  Copyright 2016 High Fidelity, Inc.
+//
+//  Utilities for working with QtScriptValues
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptValueUtils_h
+#define hifi_ScriptValueUtils_h
+
+#include <QtCore/QVector>
+
+#include <glm/glm.hpp>
+#include <glm/gtc/quaternion.hpp>
+
+#include "ScriptValue.h"
+
+bool isListOfStrings(const ScriptValue& value);
+
+
+void registerMetaTypes(ScriptEngine* engine);
+
+// Mat4
+/*@jsdoc
+ * A 4 x 4 matrix, typically containing a scale, rotation, and translation transform. See also the {@link Mat4(0)|Mat4} object.
+ *
+ * @typedef {object} Mat4
+ * @property {number} r0c0 - Row 0, column 0 value.
+ * @property {number} r1c0 - Row 1, column 0 value.
+ * @property {number} r2c0 - Row 2, column 0 value.
+ * @property {number} r3c0 - Row 3, column 0 value.
+ * @property {number} r0c1 - Row 0, column 1 value.
+ * @property {number} r1c1 - Row 1, column 1 value.
+ * @property {number} r2c1 - Row 2, column 1 value.
+ * @property {number} r3c1 - Row 3, column 1 value.
+ * @property {number} r0c2 - Row 0, column 2 value.
+ * @property {number} r1c2 - Row 1, column 2 value.
+ * @property {number} r2c2 - Row 2, column 2 value.
+ * @property {number} r3c2 - Row 3, column 2 value.
+ * @property {number} r0c3 - Row 0, column 3 value.
+ * @property {number} r1c3 - Row 1, column 3 value.
+ * @property {number} r2c3 - Row 2, column 3 value.
+ * @property {number} r3c3 - Row 3, column 3 value.
+ */
+ScriptValue mat4toScriptValue(ScriptEngine* engine, const glm::mat4& mat4);
+bool mat4FromScriptValue(const ScriptValue& object, glm::mat4& mat4);
+
+/*@jsdoc
+* A 2-dimensional vector.
+*
+* @typedef {object} Vec2
+* @property {number} x - X-coordinate of the vector. Synonyms: <code>u</code>.
+* @property {number} y - Y-coordinate of the vector. Synonyms: <code>v</code>.
+* @example <caption>Vec2s can be set in multiple ways and modified with their aliases, but still stringify in the same way</caption>
+* Entities.editEntity(<id>, { materialMappingPos: { x: 0.1, y: 0.2 }});          // { x: 0.1, y: 0.2 }
+* Entities.editEntity(<id>, { materialMappingPos: { u: 0.3, v: 0.4 }});          // { x: 0.3, y: 0.4 }
+* Entities.editEntity(<id>, { materialMappingPos: [0.5, 0.6] });                 // { x: 0.5, y: 0.6 }
+* Entities.editEntity(<id>, { materialMappingPos: 0.7 });                        // { x: 0.7, y: 0.7 }
+* var color = Entities.getEntityProperties(<id>).materialMappingPos;             // { x: 0.7, y: 0.7 }
+* color.v = 0.8;                                                                 // { x: 0.7, y: 0.8 }
+*/
+ScriptValue vec2ToScriptValue(ScriptEngine* engine, const glm::vec2& vec2);
+bool vec2FromScriptValue(const ScriptValue& object, glm::vec2& vec2);
+
+/*@jsdoc
+* A 3-dimensional vector. See also the {@link Vec3(0)|Vec3} object.
+*
+* @typedef {object} Vec3
+* @property {number} x - X-coordinate of the vector. Synonyms: <code>r</code>, <code>red</code>.
+* @property {number} y - Y-coordinate of the vector. Synonyms: <code>g</code>, <code>green</code>.
+* @property {number} z - Z-coordinate of the vector. Synonyms: <code>b</code>, <code>blue</code>.
+* @example <caption>Vec3 values can be set in multiple ways and modified with their aliases, but still stringify in the same 
+*     way.</caption>
+* Entities.editEntity(<id>, { position: { x: 1, y: 2, z: 3 }});                 // { x: 1, y: 2, z: 3 }
+* Entities.editEntity(<id>, { position: { r: 4, g: 5, b: 6 }});                 // { x: 4, y: 5, z: 6 }
+* Entities.editEntity(<id>, { position: { red: 7, green: 8, blue: 9 }});        // { x: 7, y: 8, z: 9 }
+* Entities.editEntity(<id>, { position: [10, 11, 12] });                        // { x: 10, y: 11, z: 12 }
+* Entities.editEntity(<id>, { position: 13 });                                  // { x: 13, y: 13, z: 13 }
+* var position = Entities.getEntityProperties(<id>).position;                   // { x: 13, y: 13, z: 13 }
+* position.g = 14;                                                              // { x: 13, y: 14, z: 13 }
+* position.blue = 15;                                                           // { x: 13, y: 14, z: 15 }
+* Entities.editEntity(<id>, { position: "red"});                                // { x: 255, y: 0, z: 0 }
+* Entities.editEntity(<id>, { position: "#00FF00"});                            // { x: 0, y: 255, z: 0 }
+*/
+ScriptValue vec3ToScriptValue(ScriptEngine* engine, const glm::vec3& vec3);
+ScriptValue vec3ColorToScriptValue(ScriptEngine* engine, const glm::vec3& vec3);
+bool vec3FromScriptValue(const ScriptValue& object, glm::vec3& vec3);
+
+/*@jsdoc
+ * A color vector. See also the {@link Vec3(0)|Vec3} object.
+ *
+ * @typedef {object} Color
+ * @property {number} red - Red component value. Integer in the range <code>0</code> - <code>255</code>.  Synonyms: <code>r</code>, <code>x</code>.
+ * @property {number} green - Green component value. Integer in the range <code>0</code> - <code>255</code>.  Synonyms: <code>g</code>, <code>y</code>.
+ * @property {number} blue - Blue component value. Integer in the range <code>0</code> - <code>255</code>.  Synonyms: <code>b</code>, <code>z</code>.
+ * @example <caption>Colors can be set in multiple ways and modified with their aliases, but still stringify in the same way</caption>
+ * Entities.editEntity(<id>, { color: { x: 1, y: 2, z: 3 }});                 // { red: 1, green: 2, blue: 3 }
+ * Entities.editEntity(<id>, { color: { r: 4, g: 5, b: 6 }});                 // { red: 4, green: 5, blue: 6 }
+ * Entities.editEntity(<id>, { color: { red: 7, green: 8, blue: 9 }});        // { red: 7, green: 8, blue: 9 }
+ * Entities.editEntity(<id>, { color: [10, 11, 12] });                        // { red: 10, green: 11, blue: 12 }
+ * Entities.editEntity(<id>, { color: 13 });                                  // { red: 13, green: 13, blue: 13 }
+ * var color = Entities.getEntityProperties(<id>).color;                      // { red: 13, green: 13, blue: 13 }
+ * color.g = 14;                                                              // { red: 13, green: 14, blue: 13 }
+ * color.blue = 15;                                                           // { red: 13, green: 14, blue: 15 }
+ * Entities.editEntity(<id>, { color: "red"});                                // { red: 255, green: 0, blue: 0 }
+ * Entities.editEntity(<id>, { color: "#00FF00"});                            // { red: 0, green: 255, blue: 0 }
+ */
+/*@jsdoc
+ * A color vector with real values. Values may also be <code>null</code>. See also the {@link Vec3(0)|Vec3} object.
+ *
+ * @typedef {object} ColorFloat
+ * @property {number} red - Red component value. Real in the range <code>0</code> - <code>255</code>.  Synonyms: <code>r</code>, <code>x</code>.
+ * @property {number} green - Green component value. Real in the range <code>0</code> - <code>255</code>.  Synonyms: <code>g</code>, <code>y</code>.
+ * @property {number} blue - Blue component value. Real in the range <code>0</code> - <code>255</code>.  Synonyms: <code>b</code>, <code>z</code>.
+ * @example <caption>ColorFloats can be set in multiple ways and modified with their aliases, but still stringify in the same way</caption>
+ * Entities.editEntity(<id>, { color: { x: 1, y: 2, z: 3 }});                 // { red: 1, green: 2, blue: 3 }
+ * Entities.editEntity(<id>, { color: { r: 4, g: 5, b: 6 }});                 // { red: 4, green: 5, blue: 6 }
+ * Entities.editEntity(<id>, { color: { red: 7, green: 8, blue: 9 }});        // { red: 7, green: 8, blue: 9 }
+ * Entities.editEntity(<id>, { color: [10, 11, 12] });                        // { red: 10, green: 11, blue: 12 }
+ * Entities.editEntity(<id>, { color: 13 });                                  // { red: 13, green: 13, blue: 13 }
+ * var color = Entities.getEntityProperties(<id>).color;                      // { red: 13, green: 13, blue: 13 }
+ * color.g = 14;                                                              // { red: 13, green: 14, blue: 13 }
+ * color.blue = 15;                                                           // { red: 13, green: 14, blue: 15 }
+ * Entities.editEntity(<id>, { color: "red"});                                // { red: 255, green: 0, blue: 0 }
+ * Entities.editEntity(<id>, { color: "#00FF00"});                            // { red: 0, green: 255, blue: 0 }
+ */
+ScriptValue u8vec3ToScriptValue(ScriptEngine* engine, const glm::u8vec3& vec3);
+ScriptValue u8vec3ColorToScriptValue(ScriptEngine* engine, const glm::u8vec3& vec3);
+bool u8vec3FromScriptValue(const ScriptValue& object, glm::u8vec3& vec3);
+
+/*@jsdoc
+ * A 4-dimensional vector.
+ *
+ * @typedef {object} Vec4
+ * @property {number} x - X-coordinate of the vector.
+ * @property {number} y - Y-coordinate of the vector.
+ * @property {number} z - Z-coordinate of the vector.
+ * @property {number} w - W-coordinate of the vector.
+ */
+ScriptValue vec4toScriptValue(ScriptEngine* engine, const glm::vec4& vec4);
+bool vec4FromScriptValue(const ScriptValue& object, glm::vec4& vec4);
+
+// Quaternions
+ScriptValue quatToScriptValue(ScriptEngine* engine, const glm::quat& quat);
+bool quatFromScriptValue(const ScriptValue& object, glm::quat& quat);
+
+/*@jsdoc
+ * Defines a rectangular portion of an image or screen, or similar.
+ * @typedef {object} Rect
+ * @property {number} x - Left, x-coordinate value.
+ * @property {number} y - Top, y-coordinate value.
+ * @property {number} width - Width of the rectangle.
+ * @property {number} height - Height of the rectangle.
+ */
+class QRect;
+ScriptValue qRectToScriptValue(ScriptEngine* engine, const QRect& rect);
+bool qRectFromScriptValue(const ScriptValue& object, QRect& rect);
+
+class QRectF;
+ScriptValue qRectFToScriptValue(ScriptEngine* engine, const QRectF& rect);
+bool qRectFFromScriptValue(const ScriptValue& object, QRectF& rect);
+
+// QColor
+class QColor;
+ScriptValue qColorToScriptValue(ScriptEngine* engine, const QColor& color);
+bool qColorFromScriptValue(const ScriptValue& object, QColor& color);
+
+class QUrl;
+ScriptValue qURLToScriptValue(ScriptEngine* engine, const QUrl& url);
+bool qURLFromScriptValue(const ScriptValue& object, QUrl& url);
+
+// vector<vec3>
+Q_DECLARE_METATYPE(QVector<glm::vec3>)
+ScriptValue qVectorVec3ToScriptValue(ScriptEngine* engine, const QVector<glm::vec3>& vector);
+ScriptValue qVectorVec3ColorToScriptValue(ScriptEngine* engine, const QVector<glm::vec3>& vector);
+bool qVectorVec3FromScriptValue(const ScriptValue& array, QVector<glm::vec3>& vector);
+QVector<glm::vec3> qVectorVec3FromScriptValue(const ScriptValue& array);
+
+// vector<quat>
+Q_DECLARE_METATYPE(QVector<glm::quat>)
+ScriptValue qVectorQuatToScriptValue(ScriptEngine* engine, const QVector<glm::quat>& vector);
+bool qVectorQuatFromScriptValue(const ScriptValue& array, QVector<glm::quat>& vector);
+QVector<glm::quat> qVectorQuatFromScriptValue(const ScriptValue& array);
+
+// vector<bool>
+ScriptValue qVectorBoolToScriptValue(ScriptEngine* engine, const QVector<bool>& vector);
+bool qVectorBoolFromScriptValue(const ScriptValue& array, QVector<bool>& vector);
+QVector<bool> qVectorBoolFromScriptValue(const ScriptValue& array);
+
+// vector<float>
+ScriptValue qVectorFloatToScriptValue(ScriptEngine* engine, const QVector<float>& vector);
+bool qVectorFloatFromScriptValue(const ScriptValue& array, QVector<float>& vector);
+QVector<float> qVectorFloatFromScriptValue(const ScriptValue& array);
+
+// vector<uint32_t>
+ScriptValue qVectorIntToScriptValue(ScriptEngine* engine, const QVector<uint32_t>& vector);
+bool qVectorIntFromScriptValue(const ScriptValue& array, QVector<uint32_t>& vector);
+
+ScriptValue qVectorQUuidToScriptValue(ScriptEngine* engine, const QVector<QUuid>& vector);
+bool qVectorQUuidFromScriptValue(const ScriptValue& array, QVector<QUuid>& vector);
+QVector<QUuid> qVectorQUuidFromScriptValue(const ScriptValue& array);
+
+class AACube;
+ScriptValue aaCubeToScriptValue(ScriptEngine* engine, const AACube& aaCube);
+bool aaCubeFromScriptValue(const ScriptValue& object, AACube& aaCube);
+
+class PickRay;
+ScriptValue pickRayToScriptValue(ScriptEngine* engine, const PickRay& pickRay);
+bool pickRayFromScriptValue(const ScriptValue& object, PickRay& pickRay);
+
+class Collision;
+ScriptValue collisionToScriptValue(ScriptEngine* engine, const Collision& collision);
+bool collisionFromScriptValue(const ScriptValue& object, Collision& collision);
+
+/*@jsdoc
+ * UUIDs (Universally Unique IDentifiers) are used to uniquely identify entities, avatars, and the like. They are represented 
+ * in JavaScript as strings in the format, <code>"{nnnnnnnn-nnnn-nnnn-nnnn-nnnnnnnnnnnn}"</code>, where the "n"s are
+ * hexadecimal digits.
+ * @typedef {string} Uuid
+ */
+//Q_DECLARE_METATYPE(QUuid) // don't need to do this for QUuid since it's already a meta type
+ScriptValue quuidToScriptValue(ScriptEngine* engine, const QUuid& uuid);
+bool quuidFromScriptValue(const ScriptValue& object, QUuid& uuid);
+
+//Q_DECLARE_METATYPE(QSizeF) // Don't need to to this becase it's arleady a meta type
+class QSizeF;
+ScriptValue qSizeFToScriptValue(ScriptEngine* engine, const QSizeF& qSizeF);
+bool qSizeFFromScriptValue(const ScriptValue& object, QSizeF& qSizeF);
+
+class AnimationDetails;
+ScriptValue animationDetailsToScriptValue(ScriptEngine* engine, const AnimationDetails& event);
+bool animationDetailsFromScriptValue(const ScriptValue& object, AnimationDetails& event);
+
+class MeshProxy;
+ScriptValue meshToScriptValue(ScriptEngine* engine, MeshProxy* const& in);
+bool meshFromScriptValue(const ScriptValue& value, MeshProxy*& out);
+
+class MeshProxyList;
+ScriptValue meshesToScriptValue(ScriptEngine* engine, const MeshProxyList& in);
+bool meshesFromScriptValue(const ScriptValue& value, MeshProxyList& out);
+
+class MeshFace;
+ScriptValue meshFaceToScriptValue(ScriptEngine* engine, const MeshFace& meshFace);
+bool meshFaceFromScriptValue(const ScriptValue& object, MeshFace& meshFaceResult);
+ScriptValue qVectorMeshFaceToScriptValue(ScriptEngine* engine, const QVector<MeshFace>& vector);
+bool qVectorMeshFaceFromScriptValue(const ScriptValue& array, QVector<MeshFace>& result);
+
+enum class StencilMaskMode;
+ScriptValue stencilMaskModeToScriptValue(ScriptEngine* engine, const StencilMaskMode& stencilMode);
+bool stencilMaskModeFromScriptValue(const ScriptValue& object, StencilMaskMode& stencilMode);
+
+class MiniPromise;
+bool promiseFromScriptValue(const ScriptValue& object, std::shared_ptr<MiniPromise>& promise);
+ScriptValue promiseToScriptValue(ScriptEngine* engine, const std::shared_ptr<MiniPromise>& promise);
+
+class EntityItemID;
+ScriptValue EntityItemIDtoScriptValue(ScriptEngine* engine, const EntityItemID& properties);
+bool EntityItemIDfromScriptValue(const ScriptValue& object, EntityItemID& properties);
+QVector<EntityItemID> qVectorEntityItemIDFromScriptValue(const ScriptValue& array);
+
+#endif  // #define hifi_ScriptValueUtils_h
+
+/// @}
diff --git a/libraries/script-engine/src/Scriptable.cpp b/libraries/script-engine/src/Scriptable.cpp
new file mode 100644
index 00000000000..07860ce6df1
--- /dev/null
+++ b/libraries/script-engine/src/Scriptable.cpp
@@ -0,0 +1,22 @@
+//
+//  Scriptable.cpp
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/22/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "Scriptable.h"
+
+static thread_local ScriptContext* scriptContextStore;
+
+ScriptContext* Scriptable::context() {
+    return scriptContextStore;
+}
+
+void Scriptable::setContext(ScriptContext* context) {
+    scriptContextStore = context;
+}
diff --git a/libraries/script-engine/src/Scriptable.h b/libraries/script-engine/src/Scriptable.h
new file mode 100644
index 00000000000..d2ca04ac69e
--- /dev/null
+++ b/libraries/script-engine/src/Scriptable.h
@@ -0,0 +1,60 @@
+//
+//  Scriptable.h
+//  libraries/script-engine/src
+//
+//  Created by Heather Anderson on 5/1/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_Scriptable_h
+#define hifi_Scriptable_h
+
+#include <memory>
+
+#include "ScriptContext.h"
+#include "ScriptValue.h"
+
+class ScriptEngine;
+using ScriptEnginePointer = std::shared_ptr<ScriptEngine>;
+
+/// [ScriptInterface] Provides an engine-independent interface for QScriptable
+class Scriptable {
+public:
+    static inline ScriptEnginePointer engine();
+    static ScriptContext* context();
+    static inline ScriptValue thisObject();
+    static inline int argumentCount();
+    static inline ScriptValue argument(int index);
+
+    static void setContext(ScriptContext* context);
+};
+
+ScriptEnginePointer Scriptable::engine() {
+    ScriptContext* scriptContext = context();
+    return scriptContext ? scriptContext->engine() : nullptr;
+}
+
+ScriptValue Scriptable::thisObject() {
+    ScriptContext* scriptContext = context();
+    return scriptContext ? scriptContext->thisObject() : ScriptValue();
+}
+
+int Scriptable::argumentCount() {
+    ScriptContext* scriptContext = context();
+    return scriptContext ? scriptContext->argumentCount() : 0;
+}
+
+ScriptValue Scriptable::argument(int index) {
+    ScriptContext* scriptContext = context();
+    return scriptContext ? scriptContext->argument(index) : ScriptValue();
+}
+
+#endif // hifi_Scriptable_h
+
+/// @}
diff --git a/libraries/script-engine/src/ScriptsModel.h b/libraries/script-engine/src/ScriptsModel.h
index 2c90a73d2d8..74289420914 100644
--- a/libraries/script-engine/src/ScriptsModel.h
+++ b/libraries/script-engine/src/ScriptsModel.h
@@ -144,10 +144,10 @@ class ScriptsModel : public QAbstractItemModel {
     // No JSDoc because the particulars of the parent class is provided in the @class description.
     int columnCount(const QModelIndex& parent = QModelIndex()) const override;
 
-    // Not exposed in the API because no conversion between TreeNodeBase and QScriptValue is provided.
+    // Not exposed in the API because no conversion between TreeNodeBase and ScriptValue is provided.
     TreeNodeBase* getTreeNodeFromIndex(const QModelIndex& index) const;
 
-    // Not exposed in the API because no conversion between TreeNodeBase and QScriptValue is provided.
+    // Not exposed in the API because no conversion between TreeNodeBase and ScriptValue is provided.
     QList<TreeNodeBase*> getFolderNodes(TreeNodeFolder* parent) const;
 
     enum Role {
diff --git a/libraries/script-engine/src/SpatialEvent.cpp b/libraries/script-engine/src/SpatialEvent.cpp
index 8520c0c485b..d663fae306b 100644
--- a/libraries/script-engine/src/SpatialEvent.cpp
+++ b/libraries/script-engine/src/SpatialEvent.cpp
@@ -12,6 +12,9 @@
 #include "SpatialEvent.h"
 
 #include <RegisteredMetaTypes.h>
+#include "ScriptEngine.h"
+#include "ScriptValueUtils.h"
+#include "ScriptValue.h"
 
 SpatialEvent::SpatialEvent() :
     locTranslation(0.0f),
@@ -30,17 +33,18 @@ SpatialEvent::SpatialEvent(const SpatialEvent& event) {
 }
 
 
-QScriptValue SpatialEvent::toScriptValue(QScriptEngine* engine, const SpatialEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue SpatialEvent::toScriptValue(ScriptEngine* engine, const SpatialEvent& event) {
+    ScriptValue obj = engine->newObject();
     
     obj.setProperty("locTranslation", vec3ToScriptValue(engine, event.locTranslation) );
     obj.setProperty("locRotation", quatToScriptValue(engine, event.locRotation) );
-    obj.setProperty("absTranslation", vec3ToScriptValue(engine, event.absTranslation) );
-    obj.setProperty("absRotation", quatToScriptValue(engine, event.absRotation) );
+    obj.setProperty("absTranslation", vec3ToScriptValue(engine, event.absTranslation));
+    obj.setProperty("absRotation", quatToScriptValue(engine, event.absRotation));
     
     return obj;
 }
 
-void SpatialEvent::fromScriptValue(const QScriptValue& object,SpatialEvent& event) {
+bool SpatialEvent::fromScriptValue(const ScriptValue& object, SpatialEvent& event) {
     // nothing for now...
+    return false;
 }
diff --git a/libraries/script-engine/src/SpatialEvent.h b/libraries/script-engine/src/SpatialEvent.h
index 1ea31f1ed32..bfd9142b932 100644
--- a/libraries/script-engine/src/SpatialEvent.h
+++ b/libraries/script-engine/src/SpatialEvent.h
@@ -18,7 +18,9 @@
 #include <glm/glm.hpp>
 #include <glm/gtc/quaternion.hpp>
 
-#include <qscriptengine.h>
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// [unused] Represents a spatial event to the scripting engine
 class SpatialEvent {
@@ -26,8 +28,8 @@ class SpatialEvent {
     SpatialEvent();
     SpatialEvent(const SpatialEvent& other);
     
-    static QScriptValue toScriptValue(QScriptEngine* engine, const SpatialEvent& event);
-    static void fromScriptValue(const QScriptValue& object, SpatialEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const SpatialEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, SpatialEvent& event);
     
     glm::vec3 locTranslation;
     glm::quat locRotation;
diff --git a/libraries/script-engine/src/TouchEvent.cpp b/libraries/script-engine/src/TouchEvent.cpp
index 9e9f8bd34a1..d65b585b0ae 100644
--- a/libraries/script-engine/src/TouchEvent.cpp
+++ b/libraries/script-engine/src/TouchEvent.cpp
@@ -11,12 +11,12 @@
 
 #include "TouchEvent.h"
 
-#include <qscriptengine.h>
-#include <qscriptvalue.h>
-
 #include <NumericalConstants.h>
 
 #include "RegisteredMetaTypes.h"
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
+#include "ScriptValueUtils.h"
 
 TouchEvent::TouchEvent() :
     x(0.0f),
@@ -204,8 +204,8 @@ void TouchEvent::calculateMetaAttributes(const TouchEvent& other) {
  *     print(JSON.stringify(event));
  * });
  */
-QScriptValue TouchEvent::toScriptValue(QScriptEngine* engine, const TouchEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue TouchEvent::toScriptValue(ScriptEngine* engine, const TouchEvent& event) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("x", event.x);
     obj.setProperty("y", event.y);
     obj.setProperty("isPressed", event.isPressed);
@@ -218,10 +218,10 @@ QScriptValue TouchEvent::toScriptValue(QScriptEngine* engine, const TouchEvent&
     obj.setProperty("isAlt", event.isAlt);
     obj.setProperty("touchPoints", event.touchPoints);
 
-    QScriptValue pointsObj = engine->newArray();
+    ScriptValue pointsObj = engine->newArray();
     int index = 0;
     foreach (glm::vec2 point, event.points) {
-        QScriptValue thisPoint = vec2ToScriptValue(engine, point);
+        ScriptValue thisPoint = vec2ToScriptValue(engine, point);
         pointsObj.setProperty(index, thisPoint);
         index++;
     }
@@ -232,7 +232,7 @@ QScriptValue TouchEvent::toScriptValue(QScriptEngine* engine, const TouchEvent&
 
     obj.setProperty("angle", event.angle);
     obj.setProperty("deltaAngle", event.deltaAngle);
-    QScriptValue anglesObj = engine->newArray();
+    ScriptValue anglesObj = engine->newArray();
     index = 0;
     foreach (float angle, event.angles) {
         anglesObj.setProperty(index, angle);
@@ -245,6 +245,7 @@ QScriptValue TouchEvent::toScriptValue(QScriptEngine* engine, const TouchEvent&
     return obj;
 }
 
-void TouchEvent::fromScriptValue(const QScriptValue& object, TouchEvent& event) {
+bool TouchEvent::fromScriptValue(const ScriptValue& object, TouchEvent& event) {
     // nothing for now...
+    return false;
 }
diff --git a/libraries/script-engine/src/TouchEvent.h b/libraries/script-engine/src/TouchEvent.h
index d084514ff6d..81d093f4e1e 100644
--- a/libraries/script-engine/src/TouchEvent.h
+++ b/libraries/script-engine/src/TouchEvent.h
@@ -20,8 +20,9 @@
 #include <QVector>
 #include <QTouchEvent>
 
-class QScriptValue;
-class QScriptEngine;
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a display or device event to the scripting engine. Exposed as <code><a href="https://apidocs.vircadia.dev/global.html#TouchEvent">TouchEvent</a></code>
 class TouchEvent {
@@ -30,8 +31,8 @@ class TouchEvent {
     TouchEvent(const QTouchEvent& event);
     TouchEvent(const QTouchEvent& event, const TouchEvent& other);
     
-    static QScriptValue toScriptValue(QScriptEngine* engine, const TouchEvent& event);
-    static void fromScriptValue(const QScriptValue& object, TouchEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const TouchEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, TouchEvent& event);
     
     float x;
     float y;
diff --git a/libraries/shared/src/VariantMapToScriptValue.cpp b/libraries/script-engine/src/VariantMapToScriptValue.cpp
similarity index 69%
rename from libraries/shared/src/VariantMapToScriptValue.cpp
rename to libraries/script-engine/src/VariantMapToScriptValue.cpp
index 156a438bd74..a1a50ed207d 100644
--- a/libraries/shared/src/VariantMapToScriptValue.cpp
+++ b/libraries/script-engine/src/VariantMapToScriptValue.cpp
@@ -15,20 +15,20 @@
 
 #include "SharedLogging.h"
 
-QScriptValue variantToScriptValue(QVariant& qValue, QScriptEngine& scriptEngine) {
+ScriptValue variantToScriptValue(QVariant& qValue, ScriptEngine& scriptEngine) {
     switch(qValue.type()) {
         case QVariant::Bool:
-            return qValue.toBool();
+            return scriptEngine.newValue(qValue.toBool());
             break;
         case QVariant::Int:
-            return qValue.toInt();
+            return scriptEngine.newValue(qValue.toInt());
             break;
         case QVariant::Double:
-            return qValue.toDouble();
+            return scriptEngine.newValue(qValue.toDouble());
             break;
         case QVariant::String:
         case QVariant::Url:
-            return qValue.toString();
+            return scriptEngine.newValue(qValue.toString());
             break;
         case QVariant::Map: {
             QVariantMap childMap = qValue.toMap();
@@ -42,18 +42,18 @@ QScriptValue variantToScriptValue(QVariant& qValue, QScriptEngine& scriptEngine)
         }
         default:
             if (qValue.canConvert<float>()) {
-                return qValue.toFloat();
+                return scriptEngine.newValue(qValue.toFloat());
             }
             //qCDebug(shared) << "unhandled QScript type" << qValue.type();
             break;
     }
 
-    return QScriptValue();
+    return ScriptValue();
 }
 
 
-QScriptValue variantMapToScriptValue(QVariantMap& variantMap, QScriptEngine& scriptEngine) {
-    QScriptValue scriptValue = scriptEngine.newObject();
+ScriptValue variantMapToScriptValue(QVariantMap& variantMap, ScriptEngine& scriptEngine) {
+    ScriptValue scriptValue = scriptEngine.newObject();
 
     for (QVariantMap::const_iterator iter = variantMap.begin(); iter != variantMap.end(); ++iter) {
         QString key = iter.key();
@@ -65,9 +65,9 @@ QScriptValue variantMapToScriptValue(QVariantMap& variantMap, QScriptEngine& scr
 }
 
 
-QScriptValue variantListToScriptValue(QVariantList& variantList, QScriptEngine& scriptEngine) {
+ScriptValue variantListToScriptValue(QVariantList& variantList, ScriptEngine& scriptEngine) {
 
-    QScriptValue scriptValue = scriptEngine.newArray();
+    ScriptValue scriptValue = scriptEngine.newArray();
 
     for (int i = 0; i < variantList.size(); i++) {
         scriptValue.setProperty(i, variantToScriptValue(variantList[i], scriptEngine));
diff --git a/libraries/script-engine/src/VariantMapToScriptValue.h b/libraries/script-engine/src/VariantMapToScriptValue.h
new file mode 100644
index 00000000000..956f7c2f152
--- /dev/null
+++ b/libraries/script-engine/src/VariantMapToScriptValue.h
@@ -0,0 +1,23 @@
+//
+//  VariantMapToScriptValue.h
+//  libraries/shared/src/
+//
+//  Created by Brad Hefta-Gaub on 12/6/13.
+//  Copyright 2013 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#include <QVariant>
+#include "ScriptValue.h"
+#include "ScriptEngine.h"
+
+ScriptValue variantToScriptValue(QVariant& qValue, ScriptEngine& scriptEngine);
+ScriptValue variantMapToScriptValue(QVariantMap& variantMap, ScriptEngine& scriptEngine);
+ScriptValue variantListToScriptValue(QVariantList& variantList, ScriptEngine& scriptEngine);
+
+/// @}
diff --git a/libraries/script-engine/src/Vec3.cpp b/libraries/script-engine/src/Vec3.cpp
index 2d3d4454c34..84df545bd2c 100644
--- a/libraries/script-engine/src/Vec3.cpp
+++ b/libraries/script-engine/src/Vec3.cpp
@@ -21,6 +21,7 @@
 #include "NumericalConstants.h"
 #include "ScriptEngine.h"
 #include "ScriptEngineLogging.h"
+#include "ScriptManager.h"
 
 
 float Vec3::orientedAngle(const glm::vec3& v1, const glm::vec3& v2, const glm::vec3& v3) {
@@ -32,8 +33,8 @@ void Vec3::print(const QString& label, const glm::vec3& v) {
     QString message = QString("%1 %2").arg(qPrintable(label));
     message = message.arg(glm::to_string(glm::dvec3(v)).c_str());
     qCDebug(scriptengine) << message;
-    if (ScriptEngine* scriptEngine = qobject_cast<ScriptEngine*>(engine())) {
-        scriptEngine->print(message);
+    if (ScriptManager* scriptManager = engine()->manager()) {
+        scriptManager->print(message);
     }
 }
 
diff --git a/libraries/script-engine/src/Vec3.h b/libraries/script-engine/src/Vec3.h
index 3c357ae6fc8..c1eecde45a2 100644
--- a/libraries/script-engine/src/Vec3.h
+++ b/libraries/script-engine/src/Vec3.h
@@ -20,9 +20,9 @@
 
 #include <QtCore/QObject>
 #include <QtCore/QString>
-#include <QtScript/QScriptable>
 
 #include "GLMHelpers.h"
+#include "Scriptable.h"
 
 /*@jsdoc
  * The <code>Vec3</code> API provides facilities for generating and manipulating 3-dimensional vectors. Vircadia uses a 
@@ -75,7 +75,7 @@
  *     <code>UNIT_NEG_Z</code>. <em>Read-only.</em>
  */
 /// Provides the <code><a href="https://apidocs.vircadia.dev/Vec3.html">Vec3</a></code> scripting interface
-class Vec3 : public QObject, protected QScriptable {
+class Vec3 : public QObject, protected Scriptable {
     Q_OBJECT
     Q_PROPERTY(glm::vec3 UNIT_X READ UNIT_X CONSTANT)
     Q_PROPERTY(glm::vec3 UNIT_Y READ UNIT_Y CONSTANT)
diff --git a/libraries/script-engine/src/WebSocketClass.cpp b/libraries/script-engine/src/WebSocketClass.cpp
index a001e2b2c27..fbe2b7fc063 100644
--- a/libraries/script-engine/src/WebSocketClass.cpp
+++ b/libraries/script-engine/src/WebSocketClass.cpp
@@ -14,11 +14,13 @@
 
 #include "WebSocketClass.h"
 
+#include "ScriptContext.h"
 #include "ScriptEngine.h"
-
+#include "ScriptEngineCast.h"
 #include "ScriptEngineLogging.h"
+#include "ScriptValue.h"
 
-WebSocketClass::WebSocketClass(QScriptEngine* engine, QString url) :
+WebSocketClass::WebSocketClass(ScriptEngine* engine, QString url) :
     _webSocket(new QWebSocket()),
     _engine(engine)
 {
@@ -26,7 +28,7 @@ WebSocketClass::WebSocketClass(QScriptEngine* engine, QString url) :
     _webSocket->open(url);
 }
 
-WebSocketClass::WebSocketClass(QScriptEngine* engine, QWebSocket* qWebSocket) :
+WebSocketClass::WebSocketClass(ScriptEngine* engine, QWebSocket* qWebSocket) :
     _webSocket(qWebSocket),
     _engine(engine)
 {
@@ -43,21 +45,21 @@ void WebSocketClass::initialize() {
     _binaryType = QStringLiteral("arraybuffer");
 }
 
-QScriptValue WebSocketClass::constructor(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue WebSocketClass::constructor(ScriptContext* context, ScriptEngine* engine) {
     QString url;
     if (context->argumentCount() > 0) {
         url = context->argument(0).toString();
     }
-    return engine->newQObject(new WebSocketClass(engine, url), QScriptEngine::ScriptOwnership);
+    return engine->newQObject(new WebSocketClass(engine, url), ScriptEngine::ScriptOwnership);
 }
 
 WebSocketClass::~WebSocketClass() {
     _webSocket->deleteLater();
 }
 
-void WebSocketClass::send(QScriptValue message) {
+void WebSocketClass::send(const ScriptValue& message) {
     if (message.isObject()) {
-        QByteArray ba = qscriptvalue_cast<QByteArray>(message);
+        QByteArray ba = scriptvalue_cast<QByteArray>(message);
         _webSocket->sendBinaryMessage(ba);
     } else {
         _webSocket->sendTextMessage(message.toString());
@@ -91,13 +93,13 @@ void WebSocketClass::close(QWebSocketProtocol::CloseCode closeCode, QString reas
 void WebSocketClass::handleOnClose() {
     bool hasError = (_webSocket->error() != QAbstractSocket::UnknownSocketError);
     if (_onCloseEvent.isFunction()) {
-        QScriptValueList args;
-        QScriptValue arg = _engine->newObject();
+        ScriptValueList args;
+        ScriptValue arg = _engine->newObject();
         arg.setProperty("code", hasError ? QWebSocketProtocol::CloseCodeAbnormalDisconnection : _webSocket->closeCode());
         arg.setProperty("reason", _webSocket->closeReason());
         arg.setProperty("wasClean", !hasError);
         args << arg;
-        _onCloseEvent.call(QScriptValue(), args);
+        _onCloseEvent.call(ScriptValue(), args);
     }
 }
 
@@ -170,30 +172,25 @@ void WebSocketClass::handleOnError(QAbstractSocket::SocketError error) {
  */
 void WebSocketClass::handleOnMessage(const QString& message) {
     if (_onMessageEvent.isFunction()) {
-        QScriptValueList args;
-        QScriptValue arg = _engine->newObject();
+        ScriptValueList args;
+        ScriptValue arg = _engine->newObject();
         arg.setProperty("data", message);
         args << arg;
-        _onMessageEvent.call(QScriptValue(), args);
+        _onMessageEvent.call(ScriptValue(), args);
     }
 }
 
 void WebSocketClass::handleOnBinaryMessage(const QByteArray& message) {
     if (_onMessageEvent.isFunction()) {
-        QScriptValueList args;
-        QScriptValue arg = _engine->newObject();
-        QScriptValue data = _engine->newVariant(QVariant::fromValue(message));
-        QScriptValue ctor = _engine->globalObject().property("ArrayBuffer");
-        auto array = qscriptvalue_cast<ArrayBufferClass*>(ctor.data());
-        QScriptValue arrayBuffer;
-        if (!array) {
+        ScriptValueList args;
+        ScriptValue arg = _engine->newObject();
+        ScriptValue arrayBuffer = _engine->newArrayBuffer(message);
+        if (arrayBuffer.isUndefined()) {
             qCWarning(scriptengine) << "WebSocketClass::handleOnBinaryMessage !ArrayBuffer";
-        } else {
-            arrayBuffer = _engine->newObject(array, data);
         }
         arg.setProperty("data", arrayBuffer);
         args << arg;
-        _onMessageEvent.call(QScriptValue(), args);
+        _onMessageEvent.call(ScriptValue(), args);
     }
 }
 
@@ -207,26 +204,29 @@ void WebSocketClass::handleOnOpen() {
     }
 }
 
-QScriptValue qWSCloseCodeToScriptValue(QScriptEngine* engine, const QWebSocketProtocol::CloseCode &closeCode) {
-    return closeCode;
+ScriptValue qWSCloseCodeToScriptValue(ScriptEngine* engine, const QWebSocketProtocol::CloseCode &closeCode) {
+    return engine->newValue(closeCode);
 }
 
-void qWSCloseCodeFromScriptValue(const QScriptValue &object, QWebSocketProtocol::CloseCode &closeCode) {
+bool qWSCloseCodeFromScriptValue(const ScriptValue &object, QWebSocketProtocol::CloseCode &closeCode) {
     closeCode = (QWebSocketProtocol::CloseCode)object.toUInt16();
+    return true;
 }
 
-QScriptValue webSocketToScriptValue(QScriptEngine* engine, WebSocketClass* const &in) {
-    return engine->newQObject(in, QScriptEngine::ScriptOwnership);
+ScriptValue webSocketToScriptValue(ScriptEngine* engine, WebSocketClass* const &in) {
+    return engine->newQObject(in, ScriptEngine::ScriptOwnership);
 }
 
-void webSocketFromScriptValue(const QScriptValue &object, WebSocketClass* &out) {
+bool webSocketFromScriptValue(const ScriptValue &object, WebSocketClass* &out) {
     out = qobject_cast<WebSocketClass*>(object.toQObject());
+    return true;
 }
 
-QScriptValue wscReadyStateToScriptValue(QScriptEngine* engine, const WebSocketClass::ReadyState& readyState) {
-    return readyState;
+ScriptValue wscReadyStateToScriptValue(ScriptEngine* engine, const WebSocketClass::ReadyState& readyState) {
+    return engine->newValue(readyState);
 }
 
-void wscReadyStateFromScriptValue(const QScriptValue& object, WebSocketClass::ReadyState& readyState) {
+bool wscReadyStateFromScriptValue(const ScriptValue& object, WebSocketClass::ReadyState& readyState) {
     readyState = (WebSocketClass::ReadyState)object.toUInt16();
+    return true;
 }
diff --git a/libraries/script-engine/src/WebSocketClass.h b/libraries/script-engine/src/WebSocketClass.h
index 457c955dc8f..f0b37579e1a 100644
--- a/libraries/script-engine/src/WebSocketClass.h
+++ b/libraries/script-engine/src/WebSocketClass.h
@@ -16,9 +16,13 @@
 #define hifi_WebSocketClass_h
 
 #include <QObject>
-#include <QScriptEngine>
 #include <QWebSocket>
 
+#include "ScriptValue.h"
+
+class ScriptContext;
+class ScriptEngine;
+
 /*@jsdoc
  * Provides a bi-directional, event-driven communication session between the script and another WebSocket connection. It is a 
  * near-complete implementation of the WebSocket API described in the Mozilla docs: 
@@ -88,10 +92,10 @@ class WebSocketClass : public QObject {
         Q_PROPERTY(ulong bufferedAmount READ getBufferedAmount)
         Q_PROPERTY(QString extensions READ getExtensions)
 
-        Q_PROPERTY(QScriptValue onclose READ getOnClose WRITE setOnClose)
-        Q_PROPERTY(QScriptValue onerror READ getOnError WRITE setOnError)
-        Q_PROPERTY(QScriptValue onmessage READ getOnMessage WRITE setOnMessage)
-        Q_PROPERTY(QScriptValue onopen READ getOnOpen WRITE setOnOpen)
+        Q_PROPERTY(ScriptValue onclose READ getOnClose WRITE setOnClose)
+        Q_PROPERTY(ScriptValue onerror READ getOnError WRITE setOnError)
+        Q_PROPERTY(ScriptValue onmessage READ getOnMessage WRITE setOnMessage)
+        Q_PROPERTY(ScriptValue onopen READ getOnOpen WRITE setOnOpen)
 
         Q_PROPERTY(QString protocol READ getProtocol)
         Q_PROPERTY(WebSocketClass::ReadyState readyState READ getReadyState)
@@ -103,11 +107,11 @@ class WebSocketClass : public QObject {
         Q_PROPERTY(WebSocketClass::ReadyState CLOSED READ getClosed CONSTANT)
 
 public:
-    WebSocketClass(QScriptEngine* engine, QString url);
-    WebSocketClass(QScriptEngine* engine, QWebSocket* qWebSocket);
+    WebSocketClass(ScriptEngine* engine, QString url);
+    WebSocketClass(ScriptEngine* engine, QWebSocket* qWebSocket);
     ~WebSocketClass();
 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine);
 
     /*@jsdoc
      * The state of a WebSocket connection.
@@ -168,17 +172,17 @@ class WebSocketClass : public QObject {
         }
     }
 
-    void setOnClose(QScriptValue eventFunction) { _onCloseEvent = eventFunction; }
-    QScriptValue getOnClose() { return _onCloseEvent; }
+    void setOnClose(const ScriptValue& eventFunction) { _onCloseEvent = eventFunction; }
+    ScriptValue getOnClose() { return _onCloseEvent; }
 
-    void setOnError(QScriptValue eventFunction) { _onErrorEvent = eventFunction; }
-    QScriptValue getOnError() { return _onErrorEvent; }
+    void setOnError(const ScriptValue& eventFunction) { _onErrorEvent = eventFunction; }
+    ScriptValue getOnError() { return _onErrorEvent; }
 
-    void setOnMessage(QScriptValue eventFunction) { _onMessageEvent = eventFunction; }
-    QScriptValue getOnMessage() { return _onMessageEvent; }
+    void setOnMessage(const ScriptValue& eventFunction) { _onMessageEvent = eventFunction; }
+    ScriptValue getOnMessage() { return _onMessageEvent; }
 
-    void setOnOpen(QScriptValue eventFunction) { _onOpenEvent = eventFunction; }
-    QScriptValue getOnOpen() { return _onOpenEvent; }
+    void setOnOpen(const ScriptValue& eventFunction) { _onOpenEvent = eventFunction; }
+    ScriptValue getOnOpen() { return _onOpenEvent; }
 
 public slots:
 
@@ -187,7 +191,7 @@ public slots:
      * @function WebSocket.send
      * @param {string|object} message - The message to send. If an object, it is converted to a string.
      */
-    void send(QScriptValue message);
+    void send(const ScriptValue& message);
 
     /*@jsdoc
      * Closes the connection.
@@ -225,12 +229,12 @@ public slots:
 
 private:
     QWebSocket* _webSocket;
-    QScriptEngine* _engine;
+    ScriptEngine* _engine;
 
-    QScriptValue _onCloseEvent;
-    QScriptValue _onErrorEvent;
-    QScriptValue _onMessageEvent;
-    QScriptValue _onOpenEvent;
+    ScriptValue _onCloseEvent;
+    ScriptValue _onErrorEvent;
+    ScriptValue _onMessageEvent;
+    ScriptValue _onOpenEvent;
 
     QString _binaryType;
 
@@ -248,14 +252,14 @@ private slots:
 Q_DECLARE_METATYPE(QWebSocketProtocol::CloseCode);
 Q_DECLARE_METATYPE(WebSocketClass::ReadyState);
 
-QScriptValue qWSCloseCodeToScriptValue(QScriptEngine* engine, const QWebSocketProtocol::CloseCode& closeCode);
-void qWSCloseCodeFromScriptValue(const QScriptValue& object, QWebSocketProtocol::CloseCode& closeCode);
+ScriptValue qWSCloseCodeToScriptValue(ScriptEngine* engine, const QWebSocketProtocol::CloseCode& closeCode);
+bool qWSCloseCodeFromScriptValue(const ScriptValue& object, QWebSocketProtocol::CloseCode& closeCode);
 
-QScriptValue webSocketToScriptValue(QScriptEngine* engine, WebSocketClass* const &in);
-void webSocketFromScriptValue(const QScriptValue &object, WebSocketClass* &out);
+ScriptValue webSocketToScriptValue(ScriptEngine* engine, WebSocketClass* const &in);
+bool webSocketFromScriptValue(const ScriptValue& object, WebSocketClass*& out);
 
-QScriptValue wscReadyStateToScriptValue(QScriptEngine* engine, const WebSocketClass::ReadyState& readyState);
-void wscReadyStateFromScriptValue(const QScriptValue& object, WebSocketClass::ReadyState& readyState);
+ScriptValue wscReadyStateToScriptValue(ScriptEngine* engine, const WebSocketClass::ReadyState& readyState);
+bool wscReadyStateFromScriptValue(const ScriptValue& object, WebSocketClass::ReadyState& readyState);
 
 #endif // hifi_WebSocketClass_h
 
diff --git a/libraries/script-engine/src/WebSocketServerClass.cpp b/libraries/script-engine/src/WebSocketServerClass.cpp
index 860170a3f98..304219952cb 100644
--- a/libraries/script-engine/src/WebSocketServerClass.cpp
+++ b/libraries/script-engine/src/WebSocketServerClass.cpp
@@ -13,9 +13,11 @@
 
 #include "WebSocketServerClass.h"
 
+#include "ScriptContext.h"
 #include "ScriptEngine.h"
+#include "ScriptValue.h"
 
-WebSocketServerClass::WebSocketServerClass(QScriptEngine* engine, const QString& serverName, const quint16 port) :
+WebSocketServerClass::WebSocketServerClass(ScriptEngine* engine, const QString& serverName, const quint16 port) :
     _webSocketServer(serverName, QWebSocketServer::SslMode::NonSecureMode),
     _engine(engine)
 {
@@ -24,24 +26,24 @@ WebSocketServerClass::WebSocketServerClass(QScriptEngine* engine, const QString&
     }
 }
 
-QScriptValue WebSocketServerClass::constructor(QScriptContext* context, QScriptEngine* engine) {
+ScriptValue WebSocketServerClass::constructor(ScriptContext* context, ScriptEngine* engine) {
     // the serverName is used in handshakes
     QString serverName = QStringLiteral("HighFidelity - Scripted WebSocket Listener");
     // port 0 will auto-assign a free port
     quint16 port = 0;
-    QScriptValue callee = context->callee();
+    ScriptValue callee = context->callee();
     if (context->argumentCount() > 0) {
-        QScriptValue options = context->argument(0);
-        QScriptValue portOption = options.property(QStringLiteral("port"));
+        ScriptValue options = context->argument(0);
+        ScriptValue portOption = options.property(QStringLiteral("port"));
         if (portOption.isValid() && portOption.isNumber()) {
             port = portOption.toNumber();
         }
-        QScriptValue serverNameOption = options.property(QStringLiteral("serverName"));
+        ScriptValue serverNameOption = options.property(QStringLiteral("serverName"));
         if (serverNameOption.isValid() && serverNameOption.isString()) {
             serverName = serverNameOption.toString();
         }
     }
-    return engine->newQObject(new WebSocketServerClass(engine, serverName, port), QScriptEngine::ScriptOwnership);
+    return engine->newQObject(new WebSocketServerClass(engine, serverName, port), ScriptEngine::ScriptOwnership);
 }
 
 WebSocketServerClass::~WebSocketServerClass() {
diff --git a/libraries/script-engine/src/WebSocketServerClass.h b/libraries/script-engine/src/WebSocketServerClass.h
index 7cf03d7b41d..2ff2b98a953 100644
--- a/libraries/script-engine/src/WebSocketServerClass.h
+++ b/libraries/script-engine/src/WebSocketServerClass.h
@@ -16,10 +16,14 @@
 #define hifi_WebSocketServerClass_h
 
 #include <QObject>
-#include <QScriptEngine>
 #include <QWebSocketServer>
 #include "WebSocketClass.h"
 
+#include "ScriptValue.h"
+
+class ScriptContext;
+class ScriptEngine;
+
 /*@jsdoc
  * Manages {@link WebSocket}s in server entity and assignment client scripts.
  *
@@ -84,14 +88,14 @@ class WebSocketServerClass : public QObject {
     Q_PROPERTY(bool listening READ isListening)
 
 public:
-    WebSocketServerClass(QScriptEngine* engine, const QString& serverName, const quint16 port);
+    WebSocketServerClass(ScriptEngine* engine, const QString& serverName, const quint16 port);
     ~WebSocketServerClass();
 
     QString getURL() { return _webSocketServer.serverUrl().toDisplayString(); }
     quint16 getPort() { return _webSocketServer.serverPort(); }
     bool isListening() { return _webSocketServer.isListening(); }
 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine);
 
 public slots:
 
@@ -103,7 +107,7 @@ public slots:
 
 private:
     QWebSocketServer _webSocketServer;
-    QScriptEngine* _engine;
+    ScriptEngine* _engine;
     QList<WebSocketClass*> _clients;
 
 private slots:
diff --git a/libraries/script-engine/src/WheelEvent.cpp b/libraries/script-engine/src/WheelEvent.cpp
index 565c2ddb501..e22e04d078b 100644
--- a/libraries/script-engine/src/WheelEvent.cpp
+++ b/libraries/script-engine/src/WheelEvent.cpp
@@ -11,8 +11,8 @@
 
 #include "WheelEvent.h"
 
-#include <QScriptEngine>
-#include <QScriptValue>
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
 
 WheelEvent::WheelEvent() :
     x(0.0f),
@@ -81,8 +81,8 @@ WheelEvent::WheelEvent(const QWheelEvent& event) {
  *     print(JSON.stringify(event));
  * });
  */
-QScriptValue WheelEvent::toScriptValue(QScriptEngine* engine, const WheelEvent& event) {
-    QScriptValue obj = engine->newObject();
+ScriptValue WheelEvent::toScriptValue(ScriptEngine* engine, const WheelEvent& event) {
+    ScriptValue obj = engine->newObject();
     obj.setProperty("x", event.x);
     obj.setProperty("y", event.y);
     obj.setProperty("delta", event.delta);
@@ -97,6 +97,7 @@ QScriptValue WheelEvent::toScriptValue(QScriptEngine* engine, const WheelEvent&
     return obj;
 }
 
-void WheelEvent::fromScriptValue(const QScriptValue& object, WheelEvent& event) {
+bool WheelEvent::fromScriptValue(const ScriptValue& object, WheelEvent& event) {
     // nothing for now...
+    return false;
 }
diff --git a/libraries/script-engine/src/WheelEvent.h b/libraries/script-engine/src/WheelEvent.h
index a2b14ac29df..35a3dc3c04a 100644
--- a/libraries/script-engine/src/WheelEvent.h
+++ b/libraries/script-engine/src/WheelEvent.h
@@ -18,8 +18,9 @@
 #include <QString>
 #include <QWheelEvent>
 
-class QScriptValue;
-class QScriptEngine;
+#include "ScriptValue.h"
+
+class ScriptEngine;
 
 /// Represents a mouse wheel event to the scripting engine. Exposed as <code><a href="https://apidocs.vircadia.dev/global.html#WheelEvent">WheelEvent</a></code>
 class WheelEvent {
@@ -27,8 +28,8 @@ class WheelEvent {
     WheelEvent();
     WheelEvent(const QWheelEvent& event);
     
-    static QScriptValue toScriptValue(QScriptEngine* engine, const WheelEvent& event);
-    static void fromScriptValue(const QScriptValue& object, WheelEvent& event);
+    static ScriptValue toScriptValue(ScriptEngine* engine, const WheelEvent& event);
+    static bool fromScriptValue(const ScriptValue& object, WheelEvent& event);
     
     int x;
     int y;
diff --git a/libraries/script-engine/src/XMLHttpRequestClass.cpp b/libraries/script-engine/src/XMLHttpRequestClass.cpp
index e8acba83666..fbac5120345 100644
--- a/libraries/script-engine/src/XMLHttpRequestClass.cpp
+++ b/libraries/script-engine/src/XMLHttpRequestClass.cpp
@@ -23,12 +23,17 @@
 #include <MetaverseAPI.h>
 
 #include "ResourceRequestObserver.h"
+#include "ScriptContext.h"
 #include "ScriptEngine.h"
+#include "ScriptEngineCast.h"
+#include "ScriptValue.h"
 
 Q_DECLARE_METATYPE(QByteArray*)
 
-XMLHttpRequestClass::XMLHttpRequestClass(QScriptEngine* engine) :
+XMLHttpRequestClass::XMLHttpRequestClass(ScriptEngine* engine) :
     _engine(engine),
+    _onTimeout(engine->nullValue()),
+    _onReadyStateChange(engine->nullValue()),
     _timer(this) {
 
     _request.setAttribute(QNetworkRequest::FollowRedirectsAttribute, true);
@@ -39,15 +44,15 @@ XMLHttpRequestClass::~XMLHttpRequestClass() {
     if (_reply) { _reply->deleteLater(); }
 }
 
-QScriptValue XMLHttpRequestClass::constructor(QScriptContext* context, QScriptEngine* engine) {
-    return engine->newQObject(new XMLHttpRequestClass(engine), QScriptEngine::ScriptOwnership);
+ScriptValue XMLHttpRequestClass::constructor(ScriptContext* context, ScriptEngine* engine) {
+    return engine->newQObject(new XMLHttpRequestClass(engine), ScriptEngine::ScriptOwnership);
 }
 
-QScriptValue XMLHttpRequestClass::getStatus() const {
+ScriptValue XMLHttpRequestClass::getStatus() const {
     if (_reply) {
-        return QScriptValue(_reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt());
+        return _engine->newValue(_reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt());
     } 
-    return QScriptValue(0);
+    return ScriptValue(_engine->newValue(0));
 }
 
 QString XMLHttpRequestClass::getStatusText() const {
@@ -87,7 +92,7 @@ void XMLHttpRequestClass::requestDownloadProgress(qint64 bytesReceived, qint64 b
     }
 }
 
-QScriptValue XMLHttpRequestClass::getAllResponseHeaders() const {
+ScriptValue XMLHttpRequestClass::getAllResponseHeaders() const {
     if (_reply) {
         QList<QNetworkReply::RawHeaderPair> headerList = _reply->rawHeaderPairs();
         QByteArray headers;
@@ -97,16 +102,16 @@ QScriptValue XMLHttpRequestClass::getAllResponseHeaders() const {
             headers.append(headerList[i].second);
             headers.append("\n");
         }
-        return QString(headers.data());
+        return _engine->newValue(QString(headers.data()));
     }
-    return QScriptValue("");
+    return _engine->newValue("");
 }
 
-QScriptValue XMLHttpRequestClass::getResponseHeader(const QString& name) const {
+ScriptValue XMLHttpRequestClass::getResponseHeader(const QString& name) const {
     if (_reply && _reply->hasRawHeader(name.toLatin1())) {
-        return QScriptValue(QString(_reply->rawHeader(name.toLatin1())));
+        return _engine->newValue(QString(_reply->rawHeader(name.toLatin1())));
     }
-    return QScriptValue::NullValue;
+    return _engine->nullValue();
 }
 
 /*@jsdoc
@@ -117,7 +122,7 @@ void XMLHttpRequestClass::setReadyState(ReadyState readyState) {
     if (readyState != _readyState) {
         _readyState = readyState;
         if (_onReadyStateChange.isFunction()) {
-            _onReadyStateChange.call(QScriptValue::NullValue);
+            _onReadyStateChange.call(_onReadyStateChange.engine()->nullValue());
         }
     }
 }
@@ -153,15 +158,15 @@ void XMLHttpRequestClass::open(const QString& method, const QString& url, bool a
 }
 
 void XMLHttpRequestClass::send() {
-    send(QScriptValue::NullValue);
+    send(_engine->nullValue());
 }
 
-void XMLHttpRequestClass::send(const QScriptValue& data) {
+void XMLHttpRequestClass::send(const ScriptValue& data) {
     if (_readyState == OPENED && !_reply) {
 
         if (!data.isNull()) {
             if (data.isObject()) {
-                _sendData = qscriptvalue_cast<QByteArray>(data);
+                _sendData = scriptvalue_cast<QByteArray>(data);
             } else {
                 _sendData = data.toString().toUtf8();
             }
@@ -194,7 +199,7 @@ void XMLHttpRequestClass::doSend() {
  */
 void XMLHttpRequestClass::requestTimeout() {
     if (_onTimeout.isFunction()) {
-        _onTimeout.call(QScriptValue::NullValue);
+        _onTimeout.call(_engine->nullValue());
     }
     abortRequest();
     _errorCode = QNetworkReply::TimeoutError;
@@ -217,13 +222,12 @@ void XMLHttpRequestClass::requestFinished() {
             _responseData = _engine->evaluate("(" + QString(_rawResponseData.data()) + ")");
             if (_responseData.isError()) {
                 _engine->clearExceptions();
-                _responseData = QScriptValue::NullValue;
+                _responseData = _engine->nullValue();
             }
         } else if (_responseType == "arraybuffer") {
-            QScriptValue data = _engine->newVariant(QVariant::fromValue(_rawResponseData));
-            _responseData = _engine->newObject(reinterpret_cast<ScriptEngine*>(_engine)->getArrayBufferClass(), data);
+            _responseData = _engine->newArrayBuffer(_rawResponseData);
         } else {
-            _responseData = QScriptValue(QString(_rawResponseData.data()));
+            _responseData = _engine->newValue(QString(_rawResponseData.data()));
         }
     }
 
diff --git a/libraries/script-engine/src/XMLHttpRequestClass.h b/libraries/script-engine/src/XMLHttpRequestClass.h
index 013f888be82..7e38a2155bd 100644
--- a/libraries/script-engine/src/XMLHttpRequestClass.h
+++ b/libraries/script-engine/src/XMLHttpRequestClass.h
@@ -19,11 +19,13 @@
 #include <QNetworkReply>
 #include <QNetworkRequest>
 #include <QObject>
-#include <QScriptContext>
-#include <QScriptEngine>
-#include <QScriptValue>
 #include <QTimer>
 
+#include "ScriptEngine.h"
+#include "ScriptValue.h"
+
+class ScriptContext;
+
 /*
 XMlHttpRequest object
 XMlHttpRequest.objectName string
@@ -54,7 +56,7 @@ XMlHttpRequest.open(QString,QString,bool,QString) function
 XMlHttpRequest.open(QString,QString,bool) function
 XMlHttpRequest.open(QString,QString) function
 XMlHttpRequest.send() function
-XMlHttpRequest.send(QScriptValue) function
+XMlHttpRequest.send(ScriptValue) function
 XMlHttpRequest.getAllResponseHeaders() function
 XMlHttpRequest.getResponseHeader(QString) function
 */
@@ -155,13 +157,13 @@ XMlHttpRequest.getResponseHeader(QString) function
 /// Provides the <code><a href="https://apidocs.vircadia.dev/XMLHttpRequest.html">XMLHttpRequest</a></code> scripting interface
 class XMLHttpRequestClass : public QObject {
     Q_OBJECT
-    Q_PROPERTY(QScriptValue response READ getResponse)
-    Q_PROPERTY(QScriptValue responseText READ getResponseText)
+    Q_PROPERTY(ScriptValue response READ getResponse)
+    Q_PROPERTY(ScriptValue responseText READ getResponseText)
     Q_PROPERTY(QString responseType READ getResponseType WRITE setResponseType)
-    Q_PROPERTY(QScriptValue status READ getStatus)
+    Q_PROPERTY(ScriptValue status READ getStatus)
     Q_PROPERTY(QString statusText READ getStatusText)
-    Q_PROPERTY(QScriptValue readyState READ getReadyState)
-    Q_PROPERTY(QScriptValue errorCode READ getError)
+    Q_PROPERTY(ScriptValue readyState READ getReadyState)
+    Q_PROPERTY(ScriptValue errorCode READ getError)
     Q_PROPERTY(int timeout READ getTimeout WRITE setTimeout)
 
     Q_PROPERTY(int UNSENT READ getUnsent)
@@ -171,10 +173,10 @@ class XMLHttpRequestClass : public QObject {
     Q_PROPERTY(int DONE READ getDone)
 
     // Callbacks
-    Q_PROPERTY(QScriptValue ontimeout READ getOnTimeout WRITE setOnTimeout)
-    Q_PROPERTY(QScriptValue onreadystatechange READ getOnReadyStateChange WRITE setOnReadyStateChange)
+    Q_PROPERTY(ScriptValue ontimeout READ getOnTimeout WRITE setOnTimeout)
+    Q_PROPERTY(ScriptValue onreadystatechange READ getOnReadyStateChange WRITE setOnReadyStateChange)
 public:
-    XMLHttpRequestClass(QScriptEngine* engine);
+    XMLHttpRequestClass(ScriptEngine* engine);
     ~XMLHttpRequestClass();
 
     static const int MAXIMUM_REDIRECTS = 5;
@@ -212,23 +214,23 @@ class XMLHttpRequestClass : public QObject {
     int getLoading() const { return LOADING; };
     int getDone() const { return DONE; };
 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine);
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine);
 
     int getTimeout() const { return _timeout; }
     void setTimeout(int timeout) { _timeout = timeout; }
-    QScriptValue getResponse() const { return _responseData; }
-    QScriptValue getResponseText() const { return QScriptValue(QString(_rawResponseData.data())); }
+    ScriptValue getResponse() const { return _responseData; }
+    ScriptValue getResponseText() const { return _engine->newValue(QString(_rawResponseData.data())); }
     QString getResponseType() const { return _responseType; }
     void setResponseType(const QString& responseType) { _responseType = responseType; }
-    QScriptValue getReadyState() const { return QScriptValue(_readyState); }
-    QScriptValue getError() const { return QScriptValue(_errorCode); }
-    QScriptValue getStatus() const;
+    ScriptValue getReadyState() const { return _engine->newValue(_readyState); }
+    ScriptValue getError() const { return _engine->newValue(_errorCode); }
+    ScriptValue getStatus() const;
     QString getStatusText() const;
 
-    QScriptValue getOnTimeout() const { return _onTimeout; }
-    void setOnTimeout(QScriptValue function) { _onTimeout = function; }
-    QScriptValue getOnReadyStateChange() const { return _onReadyStateChange; }
-    void setOnReadyStateChange(QScriptValue function) { _onReadyStateChange = function; }
+    ScriptValue getOnTimeout() const { return _onTimeout; }
+    void setOnTimeout(const ScriptValue& function) { _onTimeout = function; }
+    ScriptValue getOnReadyStateChange() const { return _onReadyStateChange; }
+    void setOnReadyStateChange(const ScriptValue& function) { _onReadyStateChange = function; }
 
 public slots:
 
@@ -267,14 +269,14 @@ public slots:
      * @param {*} [data] - The data to send.
      */
     void send();
-    void send(const QScriptValue& data);
+    void send(const ScriptValue& data);
 
     /*@jsdoc
      * Gets the response headers.
      * @function XMLHttpRequest.getAllResponseHeaders
      * @returns {string} The response headers, separated by <code>"\n"</code> characters.
      */
-    QScriptValue getAllResponseHeaders() const;
+    ScriptValue getAllResponseHeaders() const;
 
     /*@jsdoc
      * Gets a response header.
@@ -282,7 +284,7 @@ public slots:
      * @param {string} name - 
      * @returns {string} The response header.
      */
-    QScriptValue getResponseHeader(const QString& name) const;
+    ScriptValue getResponseHeader(const QString& name) const;
 
 signals:
 
@@ -300,7 +302,7 @@ public slots:
     void disconnectFromReply(QNetworkReply* reply);
     void abortRequest();
 
-    QScriptEngine* _engine { nullptr };
+    ScriptEngine* _engine { nullptr };
     bool _async { true };
     QUrl _url;
     QString _method;
@@ -309,9 +311,9 @@ public slots:
     QNetworkReply* _reply { nullptr };
     QByteArray _sendData;
     QByteArray _rawResponseData;
-    QScriptValue _responseData;
-    QScriptValue _onTimeout { QScriptValue::NullValue };
-    QScriptValue _onReadyStateChange { QScriptValue::NullValue };
+    ScriptValue _responseData;
+    ScriptValue _onTimeout;
+    ScriptValue _onReadyStateChange;
     ReadyState _readyState { XMLHttpRequestClass::UNSENT };
 
     /*@jsdoc
diff --git a/libraries/script-engine/src/ArrayBufferClass.cpp b/libraries/script-engine/src/qtscript/ArrayBufferClass.cpp
similarity index 94%
rename from libraries/script-engine/src/ArrayBufferClass.cpp
rename to libraries/script-engine/src/qtscript/ArrayBufferClass.cpp
index 6734114932f..ef4b3567440 100644
--- a/libraries/script-engine/src/ArrayBufferClass.cpp
+++ b/libraries/script-engine/src/qtscript/ArrayBufferClass.cpp
@@ -15,7 +15,7 @@
 
 #include "ArrayBufferPrototype.h"
 #include "DataViewClass.h"
-#include "ScriptEngine.h"
+#include "ScriptEngineQtScript.h"
 #include "TypedArrays.h"
 
 
@@ -23,12 +23,9 @@ static const QString CLASS_NAME = "ArrayBuffer";
 
 // FIXME: Q_DECLARE_METATYPE is global and really belongs in a shared header file, not per .cpp like this
 // (see DataViewClass.cpp, etc. which would also have to be updated to resolve)
-Q_DECLARE_METATYPE(QScriptClass*)
 Q_DECLARE_METATYPE(QByteArray*)
-int qScriptClassPointerMetaTypeId = qRegisterMetaType<QScriptClass*>();
-int qByteArrayPointerMetaTypeId = qRegisterMetaType<QByteArray*>();
 
-ArrayBufferClass::ArrayBufferClass(ScriptEngine* scriptEngine) :
+ArrayBufferClass::ArrayBufferClass(ScriptEngineQtScript* scriptEngine) :
 QObject(scriptEngine),
 QScriptClass(scriptEngine) {
     qScriptRegisterMetaType<QByteArray>(engine(), toScriptValue, fromScriptValue);
@@ -87,8 +84,9 @@ QScriptValue ArrayBufferClass::newInstance(qint32 size) {
 }
 
 QScriptValue ArrayBufferClass::newInstance(const QByteArray& ba) {
-    QScriptValue data = engine()->newVariant(QVariant::fromValue(ba));
-    return engine()->newObject(this, data);
+    QScriptEngine* eng = engine();
+    QScriptValue data = eng->newVariant(QVariant::fromValue(ba));
+    return eng->newObject(this, data);
 }
 
 QScriptValue ArrayBufferClass::construct(QScriptContext* context, QScriptEngine* engine) {
diff --git a/libraries/script-engine/src/ArrayBufferClass.h b/libraries/script-engine/src/qtscript/ArrayBufferClass.h
similarity index 85%
rename from libraries/script-engine/src/ArrayBufferClass.h
rename to libraries/script-engine/src/qtscript/ArrayBufferClass.h
index 6438272f5b7..c9efce1ad49 100644
--- a/libraries/script-engine/src/ArrayBufferClass.h
+++ b/libraries/script-engine/src/qtscript/ArrayBufferClass.h
@@ -15,7 +15,7 @@
 #ifndef hifi_ArrayBufferClass_h
 #define hifi_ArrayBufferClass_h
 
-#include <QScriptClass>
+#include <QtScript/QScriptClass>
 #include <QtCore/QObject>
 #include <QtScript/QScriptClass>
 #include <QtScript/QScriptContext>
@@ -24,13 +24,13 @@
 #include <QtScript/QScriptValue>
 #include <QtCore/QDateTime>
 
-class ScriptEngine;
+class ScriptEngineQtScript;
 
-/// Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></code> scripting class
+/// [QtScript] Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></code> scripting class
 class ArrayBufferClass : public QObject, public QScriptClass {
     Q_OBJECT
 public:
-    ArrayBufferClass(ScriptEngine* scriptEngine);
+    ArrayBufferClass(ScriptEngineQtScript* scriptEngine);
     QScriptValue newInstance(qint32 size);
     QScriptValue newInstance(const QByteArray& ba);
 
diff --git a/libraries/script-engine/src/ArrayBufferPrototype.cpp b/libraries/script-engine/src/qtscript/ArrayBufferPrototype.cpp
similarity index 97%
rename from libraries/script-engine/src/ArrayBufferPrototype.cpp
rename to libraries/script-engine/src/qtscript/ArrayBufferPrototype.cpp
index d75482aa2e6..ad5a68ec796 100644
--- a/libraries/script-engine/src/ArrayBufferPrototype.cpp
+++ b/libraries/script-engine/src/qtscript/ArrayBufferPrototype.cpp
@@ -13,10 +13,9 @@
 
 #include <glm/glm.hpp>
 
-#include <QBuffer>
-#include <QImage>
-
-#include "ArrayBufferClass.h"
+#include <QtCore/QBuffer>
+#include <QtGui/QImage>
+#include <QtScript/QScriptEngine>
 
 static const int QCOMPRESS_HEADER_POSITION = 0;
 static const int QCOMPRESS_HEADER_SIZE = 4;
diff --git a/libraries/script-engine/src/ArrayBufferPrototype.h b/libraries/script-engine/src/qtscript/ArrayBufferPrototype.h
similarity index 81%
rename from libraries/script-engine/src/ArrayBufferPrototype.h
rename to libraries/script-engine/src/qtscript/ArrayBufferPrototype.h
index 324f3176609..1fc5948f6bd 100644
--- a/libraries/script-engine/src/ArrayBufferPrototype.h
+++ b/libraries/script-engine/src/qtscript/ArrayBufferPrototype.h
@@ -18,7 +18,7 @@
 #include <QtCore/QObject>
 #include <QtScript/QScriptable>
 
-/// The javascript functions associated with an <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></code> instance prototype
+/// [QtScript] The javascript functions associated with an <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/ArrayBuffer">ArrayBuffer</a></code> instance prototype
 class ArrayBufferPrototype : public QObject, public QScriptable {
     Q_OBJECT
 public:
diff --git a/libraries/script-engine/src/ArrayBufferViewClass.cpp b/libraries/script-engine/src/qtscript/ArrayBufferViewClass.cpp
similarity index 89%
rename from libraries/script-engine/src/ArrayBufferViewClass.cpp
rename to libraries/script-engine/src/qtscript/ArrayBufferViewClass.cpp
index cf776ed8340..f58cbeb9433 100644
--- a/libraries/script-engine/src/ArrayBufferViewClass.cpp
+++ b/libraries/script-engine/src/qtscript/ArrayBufferViewClass.cpp
@@ -10,13 +10,15 @@
 //
 
 #include "ArrayBufferViewClass.h"
+#include "ScriptEngineQtScript.h"
 
 Q_DECLARE_METATYPE(QByteArray*)
 
-ArrayBufferViewClass::ArrayBufferViewClass(ScriptEngine* scriptEngine) :
-QObject(scriptEngine),
-QScriptClass(scriptEngine),
-_scriptEngine(scriptEngine) {
+ArrayBufferViewClass::ArrayBufferViewClass(ScriptEngineQtScript* scriptEngine) :
+    QObject(scriptEngine),
+    QScriptClass(scriptEngine),
+    _scriptEngine(scriptEngine)
+{
     // Save string handles for quick lookup
     _bufferName = engine()->toStringHandle(BUFFER_PROPERTY_NAME.toLatin1());
     _byteOffsetName = engine()->toStringHandle(BYTE_OFFSET_PROPERTY_NAME.toLatin1());
diff --git a/libraries/script-engine/src/ArrayBufferViewClass.h b/libraries/script-engine/src/qtscript/ArrayBufferViewClass.h
similarity index 83%
rename from libraries/script-engine/src/ArrayBufferViewClass.h
rename to libraries/script-engine/src/qtscript/ArrayBufferViewClass.h
index 173f6073342..e5c40d8e440 100644
--- a/libraries/script-engine/src/ArrayBufferViewClass.h
+++ b/libraries/script-engine/src/qtscript/ArrayBufferViewClass.h
@@ -15,7 +15,7 @@
 #ifndef hifi_ArrayBufferViewClass_h
 #define hifi_ArrayBufferViewClass_h
 
-#include <QScriptClass>
+#include <QtScript/QScriptClass>
 #include <QtCore/QObject>
 #include <QtScript/QScriptClass>
 #include <QtScript/QScriptContext>
@@ -23,19 +23,19 @@
 #include <QtScript/QScriptString>
 #include <QtScript/QScriptValue>
 
-#include "ScriptEngine.h"
+class ScriptEngineQtScript;
 
 static const QString BUFFER_PROPERTY_NAME = "buffer";
 static const QString BYTE_OFFSET_PROPERTY_NAME = "byteOffset";
 static const QString BYTE_LENGTH_PROPERTY_NAME = "byteLength";
 
-/// The base class containing common code for ArrayBuffer views
+/// [QtScript] The base class containing common code for ArrayBuffer views
 class ArrayBufferViewClass : public QObject, public QScriptClass {
     Q_OBJECT
 public:
-    ArrayBufferViewClass(ScriptEngine* scriptEngine);
+    ArrayBufferViewClass(ScriptEngineQtScript* scriptEngine);
 
-    ScriptEngine* getScriptEngine() { return _scriptEngine; }
+    ScriptEngineQtScript* getScriptEngine() { return _scriptEngine; }
 
     virtual QueryFlags queryProperty(const QScriptValue& object,
                                      const QScriptString& name,
@@ -50,7 +50,7 @@ class ArrayBufferViewClass : public QObject, public QScriptClass {
     QScriptString _byteOffsetName;
     QScriptString _byteLengthName;
 
-    ScriptEngine* _scriptEngine;
+    ScriptEngineQtScript* _scriptEngine;
 };
 
 #endif // hifi_ArrayBufferViewClass_h
diff --git a/libraries/script-engine/src/DataViewClass.cpp b/libraries/script-engine/src/qtscript/DataViewClass.cpp
similarity index 97%
rename from libraries/script-engine/src/DataViewClass.cpp
rename to libraries/script-engine/src/qtscript/DataViewClass.cpp
index 3cc5443973a..7d466ea42c5 100644
--- a/libraries/script-engine/src/DataViewClass.cpp
+++ b/libraries/script-engine/src/qtscript/DataViewClass.cpp
@@ -17,7 +17,7 @@ Q_DECLARE_METATYPE(QByteArray*)
 
 static const QString DATA_VIEW_NAME = "DataView";
 
-DataViewClass::DataViewClass(ScriptEngine* scriptEngine) : ArrayBufferViewClass(scriptEngine) {
+DataViewClass::DataViewClass(ScriptEngineQtScript* scriptEngine) : ArrayBufferViewClass(scriptEngine) {
     QScriptValue global = engine()->globalObject();
     
     // Save string handles for quick lookup
diff --git a/libraries/script-engine/src/DataViewClass.h b/libraries/script-engine/src/qtscript/DataViewClass.h
similarity index 78%
rename from libraries/script-engine/src/DataViewClass.h
rename to libraries/script-engine/src/qtscript/DataViewClass.h
index 179aad87d17..8b587bbd06a 100644
--- a/libraries/script-engine/src/DataViewClass.h
+++ b/libraries/script-engine/src/qtscript/DataViewClass.h
@@ -17,11 +17,11 @@
 
 #include "ArrayBufferViewClass.h"
 
-/// Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></code> scripting class
+/// [QtScript] Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></code> scripting class
 class DataViewClass : public ArrayBufferViewClass {
     Q_OBJECT
 public:
-    DataViewClass(ScriptEngine* scriptEngine);
+    DataViewClass(ScriptEngineQtScript* scriptEngine);
     QScriptValue newInstance(QScriptValue buffer, quint32 byteOffset, quint32 byteLength);
 
     QString name() const override;
diff --git a/libraries/script-engine/src/DataViewPrototype.cpp b/libraries/script-engine/src/qtscript/DataViewPrototype.cpp
similarity index 98%
rename from libraries/script-engine/src/DataViewPrototype.cpp
rename to libraries/script-engine/src/qtscript/DataViewPrototype.cpp
index ef757a5cb4d..7770e3bce50 100644
--- a/libraries/script-engine/src/DataViewPrototype.cpp
+++ b/libraries/script-engine/src/qtscript/DataViewPrototype.cpp
@@ -12,10 +12,15 @@
 #include "DataViewPrototype.h"
 
 #include <QDebug>
+#include <QtCore/QDataStream>
+#include <QtScript/QScriptEngine>
+#include <QtScript/QScriptValue>
 
 #include <glm/glm.hpp>
 
-#include "DataViewClass.h"
+#include <SharedUtil.h>
+
+#include "ArrayBufferViewClass.h"
 
 Q_DECLARE_METATYPE(QByteArray*)
 
diff --git a/libraries/script-engine/src/DataViewPrototype.h b/libraries/script-engine/src/qtscript/DataViewPrototype.h
similarity index 93%
rename from libraries/script-engine/src/DataViewPrototype.h
rename to libraries/script-engine/src/qtscript/DataViewPrototype.h
index b4d9462e8f6..3f395516c13 100644
--- a/libraries/script-engine/src/DataViewPrototype.h
+++ b/libraries/script-engine/src/qtscript/DataViewPrototype.h
@@ -18,7 +18,7 @@
 #include <QtCore/QObject>
 #include <QtScript/QScriptable>
 
-/// The javascript functions associated with a <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></code> instance prototype
+/// [QtScript] The javascript functions associated with a <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView">DataView</a></code> instance prototype
 class DataViewPrototype : public QObject, public QScriptable {
     Q_OBJECT
 public:
diff --git a/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.cpp b/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.cpp
new file mode 100644
index 00000000000..72f6ea41b13
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.cpp
@@ -0,0 +1,92 @@
+//
+//  ScriptContextQtWrapper.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 5/22/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptContextQtWrapper.h"
+
+#include <QtScript/QScriptContext>
+
+#include "ScriptEngineQtScript.h"
+#include "ScriptValueQtWrapper.h"
+
+ScriptContextQtWrapper* ScriptContextQtWrapper::unwrap(ScriptContext* val) {
+    if (!val) {
+        return nullptr;
+    }
+
+    return dynamic_cast<ScriptContextQtWrapper*>(val);
+}
+
+int ScriptContextQtWrapper::argumentCount() const {
+    return _context->argumentCount();
+}
+
+ScriptValue ScriptContextQtWrapper::argument(int index) const {
+    QScriptValue result = _context->argument(index);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+QStringList ScriptContextQtWrapper::backtrace() const {
+    return _context->backtrace();
+}
+
+ScriptValue ScriptContextQtWrapper::callee() const {
+    QScriptValue result = _context->callee();
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptEnginePointer ScriptContextQtWrapper::engine() const {
+    return _engine->shared_from_this();
+}
+
+ScriptFunctionContextPointer ScriptContextQtWrapper::functionContext() const {
+    return std::make_shared<ScriptFunctionContextQtWrapper>(_context);
+}
+
+ScriptContextPointer ScriptContextQtWrapper::parentContext() const {
+    QScriptContext* result = _context->parentContext();
+    return result ? std::make_shared<ScriptContextQtWrapper>(_engine, result) : ScriptContextPointer();
+}
+
+ScriptValue ScriptContextQtWrapper::thisObject() const {
+    QScriptValue result = _context->thisObject();
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptContextQtWrapper::throwError(const QString& text) {
+    QScriptValue result = _context->throwError(text);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptContextQtWrapper::throwValue(const ScriptValue& value) {
+    ScriptValueQtWrapper* unwrapped = ScriptValueQtWrapper::unwrap(value);
+    if (!unwrapped) {
+        return _engine->undefinedValue();
+    }
+    QScriptValue result = _context->throwValue(unwrapped->toQtValue());
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+
+QString ScriptFunctionContextQtWrapper::fileName() const {
+    return _value.fileName();
+}
+
+QString ScriptFunctionContextQtWrapper::functionName() const {
+    return _value.functionName();
+}
+
+ScriptFunctionContext::FunctionType ScriptFunctionContextQtWrapper::functionType() const {
+    return static_cast<ScriptFunctionContext::FunctionType>(_value.functionType());
+}
+
+int ScriptFunctionContextQtWrapper::lineNumber() const {
+    return _value.lineNumber();
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.h b/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.h
new file mode 100644
index 00000000000..bbf9f0465cf
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptContextQtWrapper.h
@@ -0,0 +1,67 @@
+//
+//  ScriptContextQtWrapper.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 5/22/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptContextQtWrapper_h
+#define hifi_ScriptContextQtWrapper_h
+
+#include <QtCore/QString>
+#include <QtScript/QScriptContextInfo>
+
+#include "../ScriptContext.h"
+#include "../ScriptValue.h"
+
+class QScriptContext;
+class ScriptEngineQtScript;
+
+/// [QtScript] Implements ScriptContext for QtScript and translates calls for QScriptContextInfo
+class ScriptContextQtWrapper final : public ScriptContext {
+public: // construction
+    inline ScriptContextQtWrapper(ScriptEngineQtScript* engine, QScriptContext* context) : _context(context) , _engine(engine) {}
+    static ScriptContextQtWrapper* unwrap(ScriptContext* val);
+    inline QScriptContext* toQtValue() const { return _context; }
+
+public: // ScriptContext implementation
+    virtual int argumentCount() const override;
+    virtual ScriptValue argument(int index) const override;
+    virtual QStringList backtrace() const override;
+    virtual ScriptValue callee() const override;
+    virtual ScriptEnginePointer engine() const override;
+    virtual ScriptFunctionContextPointer functionContext() const override;
+    virtual ScriptContextPointer parentContext() const override;
+    virtual ScriptValue thisObject() const override;
+    virtual ScriptValue throwError(const QString& text) override;
+    virtual ScriptValue throwValue(const ScriptValue& value) override;
+
+private: // storage
+    QScriptContext* _context;
+    ScriptEngineQtScript* _engine;
+};
+
+class ScriptFunctionContextQtWrapper final : public ScriptFunctionContext {
+public:  // construction
+    inline ScriptFunctionContextQtWrapper(QScriptContext* context) : _value(context) {}
+
+public:  // ScriptFunctionContext implementation
+    virtual QString fileName() const override;
+    virtual QString functionName() const override;
+    virtual FunctionType functionType() const override;
+    virtual int lineNumber() const override;
+
+private: // storage
+    QScriptContextInfo _value;
+};
+
+#endif  // hifi_ScriptContextQtWrapper_h
+
+/// @}
diff --git a/libraries/script-engine/src/qtscript/ScriptEngineQtScript.cpp b/libraries/script-engine/src/qtscript/ScriptEngineQtScript.cpp
new file mode 100644
index 00000000000..7b4a39f9428
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptEngineQtScript.cpp
@@ -0,0 +1,919 @@
+//
+//  ScriptEngineQtScript.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Brad Hefta-Gaub on 12/14/13.
+//  Copyright 2013 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptEngineQtScript.h"
+
+#include <chrono>
+#include <thread>
+
+#include <QtCore/QCoreApplication>
+#include <QtCore/QEventLoop>
+#include <QtCore/QFileInfo>
+#include <QtCore/QTimer>
+#include <QtCore/QThread>
+#include <QtCore/QRegularExpression>
+
+#include <QtCore/QFuture>
+#include <QtConcurrent/QtConcurrentRun>
+
+#include <QtWidgets/QMainWindow>
+#include <QtWidgets/QApplication>
+#include <QtWidgets/QMenuBar>
+#include <QtWidgets/QMenu>
+
+#include <QtNetwork/QNetworkRequest>
+#include <QtNetwork/QNetworkReply>
+
+#include <QtScript/QScriptContextInfo>
+#include <QtScript/QScriptValue>
+#include <QtScript/QScriptValueIterator>
+
+#include <QtScriptTools/QScriptEngineDebugger>
+
+#include <shared/LocalFileAccessGate.h>
+#include <shared/QtHelpers.h>
+#include <shared/AbstractLoggerInterface.h>
+
+#include <Profile.h>
+
+#include "../ScriptEngineLogging.h"
+#include "../ScriptProgram.h"
+#include "../ScriptValue.h"
+
+#include "ScriptContextQtWrapper.h"
+#include "ScriptObjectQtProxy.h"
+#include "ScriptProgramQtWrapper.h"
+#include "ScriptValueQtWrapper.h"
+
+static const int MAX_DEBUG_VALUE_LENGTH { 80 };
+
+bool ScriptEngineQtScript::IS_THREADSAFE_INVOCATION(const QThread* thread, const QString& method) {
+    const QThread* currentThread = QThread::currentThread();
+    if (currentThread == thread) {
+        return true;
+    }
+    qCCritical(scriptengine) << QString("Scripting::%1 @ %2 -- ignoring thread-unsafe call from %3")
+                              .arg(method)
+                              .arg(thread ? thread->objectName() : "(!thread)")
+                              .arg(QThread::currentThread()->objectName());
+    qCDebug(scriptengine) << "(please resolve on the calling side by using invokeMethod, executeOnScriptThread, etc.)";
+    Q_ASSERT(false);
+    return false;
+}
+
+// engine-aware JS Error copier and factory
+QScriptValue ScriptEngineQtScript::makeError(const QScriptValue& _other, const QString& type) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return QScriptEngine::nullValue();
+    }
+    auto other = _other;
+    if (other.isString()) {
+        other = QScriptEngine::newObject();
+        other.setProperty("message", _other.toString());
+    }
+    auto proto = QScriptEngine::globalObject().property(type);
+    if (!proto.isFunction()) {
+        proto = QScriptEngine::globalObject().property(other.prototype().property("constructor").property("name").toString());
+    }
+    if (!proto.isFunction()) {
+#ifdef DEBUG_JS_EXCEPTIONS
+        qCDebug(shared) << "BaseScriptEngine::makeError -- couldn't find constructor for" << type << " -- using Error instead";
+#endif
+        proto = QScriptEngine::globalObject().property("Error");
+    }
+    if (other.engine() != this) {
+        // JS Objects are parented to a specific script engine instance
+        // -- this effectively ~clones it locally by routing through a QVariant and back
+        other = QScriptEngine::toScriptValue(other.toVariant());
+    }
+    // ~ var err = new Error(other.message)
+    auto err = proto.construct(QScriptValueList({ other.property("message") }));
+
+    // transfer over any existing properties
+    QScriptValueIterator it(other);
+    while (it.hasNext()) {
+        it.next();
+        err.setProperty(it.name(), it.value());
+    }
+    return err;
+}
+
+ScriptValue ScriptEngineQtScript::makeError(const ScriptValue& _other, const QString& type) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return nullValue();
+    }
+    ScriptValueQtWrapper* unwrapped = ScriptValueQtWrapper::unwrap(_other);
+    QScriptValue other;
+    if (_other.isString()) {
+        other = QScriptEngine::newObject();
+        other.setProperty("message", _other.toString());
+    } else if (unwrapped) {
+        other = unwrapped->toQtValue();
+    } else {
+        other = QScriptEngine::newVariant(_other.toVariant());
+    }
+    QScriptValue result = makeError(other, type);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+// check syntax and when there are issues returns an actual "SyntaxError" with the details
+ScriptValue ScriptEngineQtScript::lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return nullValue();
+    }
+    const auto syntaxCheck = checkSyntax(sourceCode);
+    if (syntaxCheck.state() != QScriptSyntaxCheckResult::Valid) {
+        auto err = QScriptEngine::globalObject().property("SyntaxError").construct(QScriptValueList({ syntaxCheck.errorMessage() }));
+        err.setProperty("fileName", fileName);
+        err.setProperty("lineNumber", syntaxCheck.errorLineNumber());
+        err.setProperty("expressionBeginOffset", syntaxCheck.errorColumnNumber());
+        err.setProperty("stack", currentContext()->backtrace().join(ScriptManager::SCRIPT_BACKTRACE_SEP));
+        {
+            const auto error = syntaxCheck.errorMessage();
+            const auto line = QString::number(syntaxCheck.errorLineNumber());
+            const auto column = QString::number(syntaxCheck.errorColumnNumber());
+            // for compatibility with legacy reporting
+            const auto message = QString("[SyntaxError] %1 in %2:%3(%4)").arg(error, fileName, line, column);
+            err.setProperty("formatted", message);
+        }
+        return ScriptValue(new ScriptValueQtWrapper(this, std::move(err)));
+    }
+    return undefinedValue();
+}
+
+// this pulls from the best available information to create a detailed snapshot of the current exception
+ScriptValue ScriptEngineQtScript::cloneUncaughtException(const QString& extraDetail) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return nullValue();
+    }
+    if (!hasUncaughtException()) {
+        return nullValue();
+    }
+    auto exception = uncaughtException();
+    // ensure the error object is engine-local
+    auto err = makeError(exception);
+
+    // not sure why Qt does't offer uncaughtExceptionFileName -- but the line number
+    // on its own is often useless/wrong if arbitrarily married to a filename.
+    // when the error object already has this info, it seems to be the most reliable
+    auto fileName = exception.property("fileName").toString();
+    auto lineNumber = exception.property("lineNumber").toInt32();
+
+    // the backtrace, on the other hand, seems most reliable taken from uncaughtExceptionBacktrace
+    auto backtrace = uncaughtExceptionBacktrace();
+    if (backtrace.isEmpty()) {
+        // fallback to the error object
+        backtrace = exception.property("stack").toString().split(ScriptManager::SCRIPT_BACKTRACE_SEP);
+    }
+    // the ad hoc "detail" property can be used now to embed additional clues
+    auto detail = exception.property("detail").toString();
+    if (detail.isEmpty()) {
+        detail = extraDetail;
+    } else if (!extraDetail.isEmpty()) {
+        detail += "(" + extraDetail + ")";
+    }
+    if (lineNumber <= 0) {
+        lineNumber = uncaughtExceptionLineNumber();
+    }
+    if (fileName.isEmpty()) {
+        // climb the stack frames looking for something useful to display
+        for (auto c = QScriptEngine::currentContext(); c && fileName.isEmpty(); c = c->parentContext()) {
+            QScriptContextInfo info{ c };
+            if (!info.fileName().isEmpty()) {
+                // take fileName:lineNumber as a pair
+                fileName = info.fileName();
+                lineNumber = info.lineNumber();
+                if (backtrace.isEmpty()) {
+                    backtrace = c->backtrace();
+                }
+                break;
+            }
+        }
+    }
+    err.setProperty("fileName", fileName);
+    err.setProperty("lineNumber", lineNumber);
+    err.setProperty("detail", detail);
+    err.setProperty("stack", backtrace.join(ScriptManager::SCRIPT_BACKTRACE_SEP));
+
+#ifdef DEBUG_JS_EXCEPTIONS
+    err.setProperty("_fileName", exception.property("fileName").toString());
+    err.setProperty("_stack", uncaughtExceptionBacktrace().join(SCRIPT_BACKTRACE_SEP));
+    err.setProperty("_lineNumber", uncaughtExceptionLineNumber());
+#endif
+    return err;
+}
+
+bool ScriptEngineQtScript::raiseException(const QScriptValue& exception) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return false;
+    }
+    if (QScriptEngine::currentContext()) {
+        // we have an active context / JS stack frame so throw the exception per usual
+        QScriptEngine::currentContext()->throwValue(makeError(exception));
+        return true;
+    } else if (_scriptManager) {
+        // we are within a pure C++ stack frame (ie: being called directly by other C++ code)
+        // in this case no context information is available so just emit the exception for reporting
+        QScriptValue thrown = makeError(exception);
+        emit _scriptManager->unhandledException(ScriptValue(new ScriptValueQtWrapper(this, std::move(thrown))));
+    }
+    return false;
+}
+
+bool ScriptEngineQtScript::maybeEmitUncaughtException(const QString& debugHint) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return false;
+    }
+    if (!isEvaluating() && hasUncaughtException() && _scriptManager) {
+        emit _scriptManager->unhandledException(cloneUncaughtException(debugHint));
+        clearExceptions();
+        return true;
+    }
+    return false;
+}
+
+// Lambda
+QScriptValue ScriptEngineQtScript::newLambdaFunction(std::function<QScriptValue(QScriptContext*, ScriptEngineQtScript*)> operation,
+                                                 const QScriptValue& data,
+                                                 const QScriptEngine::ValueOwnership& ownership) {
+    auto lambda = new Lambda(this, operation, data);
+    auto object = QScriptEngine::newQObject(lambda, ownership);
+    auto call = object.property("call");
+    call.setPrototype(object);  // context->callee().prototype() === Lambda QObject
+    call.setData(data);         // context->callee().data() will === data param
+    return call;
+}
+QString Lambda::toString() const {
+    return QString("[Lambda%1]").arg(data.isValid() ? " " + data.toString() : data.toString());
+}
+
+Lambda::~Lambda() {
+#ifdef DEBUG_JS_LAMBDA_FUNCS
+    qDebug() << "~Lambda"
+             << "this" << this;
+#endif
+}
+
+Lambda::Lambda(ScriptEngineQtScript* engine,
+               std::function<QScriptValue(QScriptContext*, ScriptEngineQtScript*)> operation,
+               QScriptValue data) :
+    engine(engine),
+    operation(operation), data(data) {
+#ifdef DEBUG_JS_LAMBDA_FUNCS
+    qDebug() << "Lambda" << data.toString();
+#endif
+}
+QScriptValue Lambda::call() {
+    if (!engine->IS_THREADSAFE_INVOCATION(__FUNCTION__)) {
+        return static_cast<QScriptEngine*>(engine)->nullValue();
+    }
+    return operation(static_cast<QScriptEngine*>(engine)->currentContext(), engine);
+}
+
+#ifdef DEBUG_JS
+void ScriptEngineQtScript::_debugDump(const QString& header, const QScriptValue& object, const QString& footer) {
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return;
+    }
+    if (!header.isEmpty()) {
+        qCDebug(shared) << header;
+    }
+    if (!object.isObject()) {
+        qCDebug(shared) << "(!isObject)" << object.toVariant().toString() << object.toString();
+        return;
+    }
+    QScriptValueIterator it(object);
+    while (it.hasNext()) {
+        it.next();
+        qCDebug(shared) << it.name() << ":" << it.value().toString();
+    }
+    if (!footer.isEmpty()) {
+        qCDebug(shared) << footer;
+    }
+}
+#endif
+
+ScriptEngineQtScript::ScriptEngineQtScript(ScriptManager* scriptManager) :
+    QScriptEngine(),
+    _scriptManager(scriptManager),
+    _arrayBufferClass(new ArrayBufferClass(this))
+{
+    registerSystemTypes();
+
+    if (_scriptManager) {
+        connect(this, &QScriptEngine::signalHandlerException, this, [this](const QScriptValue& exception) {
+            if (hasUncaughtException()) {
+                // the engine's uncaughtException() seems to produce much better stack traces here
+                emit _scriptManager->unhandledException(cloneUncaughtException("signalHandlerException"));
+                clearExceptions();
+            } else {
+                // ... but may not always be available -- so if needed we fallback to the passed exception
+                QScriptValue thrown = makeError(exception);
+                emit _scriptManager->unhandledException(ScriptValue(new ScriptValueQtWrapper(this, std::move(thrown))));
+            }
+        }, Qt::DirectConnection);
+        moveToThread(scriptManager->thread());
+    }
+
+    QScriptValue null = QScriptEngine::nullValue();
+    _nullValue = ScriptValue(new ScriptValueQtWrapper(this, std::move(null)));
+
+    QScriptValue undefined = QScriptEngine::undefinedValue();
+    _undefinedValue = ScriptValue(new ScriptValueQtWrapper(this, std::move(undefined)));
+
+    QScriptEngine::setProcessEventsInterval(MSECS_PER_SECOND);
+}
+
+void ScriptEngineQtScript::registerEnum(const QString& enumName, QMetaEnum newEnum) {
+    if (!newEnum.isValid()) {
+        qCCritical(scriptengine) << "registerEnum called on invalid enum with name " << enumName;
+        return;
+    }
+
+    for (int i = 0; i < newEnum.keyCount(); i++) {
+        const char* keyName = newEnum.key(i);
+        QString fullName = enumName + "." + keyName;
+        registerValue(fullName, newEnum.keyToValue(keyName));
+    }
+}
+
+void ScriptEngineQtScript::registerValue(const QString& valueName, QScriptValue value) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerValue() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]";
+#endif
+        QMetaObject::invokeMethod(this, "registerValue",
+                                  Q_ARG(const QString&, valueName),
+                                  Q_ARG(QScriptValue, value));
+        return;
+    }
+
+    QStringList pathToValue = valueName.split(".");
+    int partsToGo = pathToValue.length();
+    QScriptValue partObject = QScriptEngine::globalObject();
+
+    for (const auto& pathPart : pathToValue) {
+        partsToGo--;
+        if (!partObject.property(pathPart).isValid()) {
+            if (partsToGo > 0) {
+                //QObject *object = new QObject;
+                QScriptValue partValue = QScriptEngine::newArray();  //newQObject(object, QScriptEngine::ScriptOwnership);
+                partObject.setProperty(pathPart, partValue);
+            } else {
+                partObject.setProperty(pathPart, value);
+            }
+        }
+        partObject = partObject.property(pathPart);
+    }
+}
+
+void ScriptEngineQtScript::registerGlobalObject(const QString& name, QObject* object) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerGlobalObject() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "]  name:" << name;
+#endif
+        QMetaObject::invokeMethod(this, "registerGlobalObject",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(QObject*, object));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerGlobalObject() called on thread [" << QThread::currentThread() << "] name:" << name;
+#endif
+
+    if (!QScriptEngine::globalObject().property(name).isValid()) {
+        if (object) {
+            QScriptValue value = ScriptObjectQtProxy::newQObject(this, object, ScriptEngine::QtOwnership);
+            QScriptEngine::globalObject().setProperty(name, value);
+        } else {
+            QScriptEngine::globalObject().setProperty(name, QScriptValue());
+        }
+    }
+}
+
+void ScriptEngineQtScript::registerFunction(const QString& name, QScriptEngine::FunctionSignature functionSignature, int numArguments) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] name:" << name;
+#endif
+        QMetaObject::invokeMethod(this, "registerFunction",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(QScriptEngine::FunctionSignature, functionSignature),
+                                  Q_ARG(int, numArguments));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerFunction() called on thread [" << QThread::currentThread() << "] name:" << name;
+#endif
+
+    QScriptValue scriptFun = QScriptEngine::newFunction(functionSignature, numArguments);
+    QScriptEngine::globalObject().setProperty(name, scriptFun);
+}
+
+void ScriptEngineQtScript::registerFunction(const QString& name, ScriptEngine::FunctionSignature functionSignature, int numArguments) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] name:" << name;
+#endif
+        QMetaObject::invokeMethod(this, "registerFunction",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(ScriptEngine::FunctionSignature, functionSignature),
+                                  Q_ARG(int, numArguments));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerFunction() called on thread [" << QThread::currentThread() << "] name:" << name;
+#endif
+
+    auto scriptFun = newFunction(functionSignature, numArguments);
+    globalObject().setProperty(name, scriptFun);
+}
+
+void ScriptEngineQtScript::registerFunction(const QString& parent, const QString& name, QScriptEngine::FunctionSignature functionSignature, int numArguments) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] parent:" << parent << "name:" << name;
+#endif
+        QMetaObject::invokeMethod(this, "registerFunction",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(QScriptEngine::FunctionSignature, functionSignature),
+                                  Q_ARG(int, numArguments));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerFunction() called on thread [" << QThread::currentThread() << "] parent:" << parent << "name:" << name;
+#endif
+
+    QScriptValue object = QScriptEngine::globalObject().property(parent);
+    if (object.isValid()) {
+        QScriptValue scriptFun = QScriptEngine::newFunction(functionSignature, numArguments);
+        object.setProperty(name, scriptFun);
+    }
+}
+
+void ScriptEngineQtScript::registerFunction(const QString& parent, const QString& name, ScriptEngine::FunctionSignature functionSignature, int numArguments) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerFunction() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] parent:" << parent << "name:" << name;
+#endif
+        QMetaObject::invokeMethod(this, "registerFunction",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(ScriptEngine::FunctionSignature, functionSignature),
+                                  Q_ARG(int, numArguments));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerFunction() called on thread [" << QThread::currentThread() << "] parent:" << parent << "name:" << name;
+#endif
+
+    auto object = globalObject().property(parent);
+    if (object.isValid()) {
+        auto scriptFun = newFunction(functionSignature, numArguments);
+        object.setProperty(name, scriptFun);
+    }
+}
+
+void ScriptEngineQtScript::registerGetterSetter(const QString& name, QScriptEngine::FunctionSignature getter,
+                                        QScriptEngine::FunctionSignature setter, const QString& parent) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerGetterSetter() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+            " name:" << name << "parent:" << parent;
+#endif
+        QMetaObject::invokeMethod(this, "registerGetterSetter",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(QScriptEngine::FunctionSignature, getter),
+                                  Q_ARG(QScriptEngine::FunctionSignature, setter),
+                                  Q_ARG(const QString&, parent));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerGetterSetter() called on thread [" << QThread::currentThread() << "] name:" << name << "parent:" << parent;
+#endif
+
+    QScriptValue setterFunction = QScriptEngine::newFunction(setter, 1);
+    QScriptValue getterFunction = QScriptEngine::newFunction(getter);
+
+    if (!parent.isNull() && !parent.isEmpty()) {
+        QScriptValue object = QScriptEngine::globalObject().property(parent);
+        if (object.isValid()) {
+            object.setProperty(name, setterFunction, QScriptValue::PropertySetter);
+            object.setProperty(name, getterFunction, QScriptValue::PropertyGetter);
+        }
+    } else {
+        QScriptEngine::globalObject().setProperty(name, setterFunction, QScriptValue::PropertySetter);
+        QScriptEngine::globalObject().setProperty(name, getterFunction, QScriptValue::PropertyGetter);
+    }
+}
+
+void ScriptEngineQtScript::registerGetterSetter(const QString& name, ScriptEngine::FunctionSignature getter,
+                                        ScriptEngine::FunctionSignature setter, const QString& parent) {
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::registerGetterSetter() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+            " name:" << name << "parent:" << parent;
+#endif
+        QMetaObject::invokeMethod(this, "registerGetterSetter",
+                                  Q_ARG(const QString&, name),
+                                  Q_ARG(ScriptEngine::FunctionSignature, getter),
+                                  Q_ARG(ScriptEngine::FunctionSignature, setter),
+                                  Q_ARG(const QString&, parent));
+        return;
+    }
+#ifdef THREAD_DEBUGGING
+    qCDebug(scriptengine) << "ScriptEngineQtScript::registerGetterSetter() called on thread [" << QThread::currentThread() << "] name:" << name << "parent:" << parent;
+#endif
+
+    auto setterFunction = newFunction(setter, 1);
+    auto getterFunction = newFunction(getter);
+
+    if (!parent.isNull() && !parent.isEmpty()) {
+        auto object = globalObject().property(parent);
+        if (object.isValid()) {
+            object.setProperty(name, setterFunction, ScriptValue::PropertySetter);
+            object.setProperty(name, getterFunction, ScriptValue::PropertyGetter);
+        }
+    } else {
+        globalObject().setProperty(name, setterFunction, ScriptValue::PropertySetter);
+        globalObject().setProperty(name, getterFunction, ScriptValue::PropertyGetter);
+    }
+}
+
+ScriptValue ScriptEngineQtScript::evaluateInClosure(const ScriptValue& _closure,
+                                                           const ScriptProgramPointer& _program) {
+    PROFILE_RANGE(script, "evaluateInClosure");
+    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
+        return nullValue();
+    }
+    ScriptProgramQtWrapper* unwrappedProgram = ScriptProgramQtWrapper::unwrap(_program);
+    if (unwrappedProgram == nullptr) {
+        return nullValue();
+    }
+    const QScriptProgram& program = unwrappedProgram->toQtValue();
+
+    const auto fileName = program.fileName();
+    const auto shortName = QUrl(fileName).fileName();
+
+    ScriptValueQtWrapper* unwrappedClosure = ScriptValueQtWrapper::unwrap(_closure);
+    if (unwrappedClosure == nullptr) {
+        return nullValue();
+    }
+    const QScriptValue& closure = unwrappedClosure->toQtValue();
+
+    QScriptValue oldGlobal;
+    auto global = closure.property("global");
+    if (global.isObject()) {
+#ifdef DEBUG_JS
+        qCDebug(shared) << " setting global = closure.global" << shortName;
+#endif
+        oldGlobal = QScriptEngine::globalObject();
+        setGlobalObject(global);
+    }
+
+    auto context = pushContext();
+
+    auto thiz = closure.property("this");
+    if (thiz.isObject()) {
+#ifdef DEBUG_JS
+        qCDebug(shared) << " setting this = closure.this" << shortName;
+#endif
+        context->setThisObject(thiz);
+    }
+
+    context->pushScope(closure);
+#ifdef DEBUG_JS
+    qCDebug(shared) << QString("[%1] evaluateInClosure %2").arg(isEvaluating()).arg(shortName);
+#endif
+    ScriptValue result;
+    {
+        auto qResult = QScriptEngine::evaluate(program);
+
+        if (hasUncaughtException()) {
+            auto err = cloneUncaughtException(__FUNCTION__);
+#ifdef DEBUG_JS_EXCEPTIONS
+            qCWarning(shared) << __FUNCTION__ << "---------- hasCaught:" << err.toString() << result.toString();
+            err.setProperty("_result", result);
+#endif
+            result = err;
+        } else {
+            result = ScriptValue(new ScriptValueQtWrapper(this, std::move(qResult)));
+        }
+    }
+#ifdef DEBUG_JS
+    qCDebug(shared) << QString("[%1] //evaluateInClosure %2").arg(isEvaluating()).arg(shortName);
+#endif
+    popContext();
+
+    if (oldGlobal.isValid()) {
+#ifdef DEBUG_JS
+        qCDebug(shared) << " restoring global" << shortName;
+#endif
+        setGlobalObject(oldGlobal);
+    }
+
+    return result;
+}
+
+ScriptValue ScriptEngineQtScript::evaluate(const QString& sourceCode, const QString& fileName) {
+    if (_scriptManager && _scriptManager->isStopped()) {
+        return undefinedValue(); // bail early
+    }
+
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+        ScriptValue result;
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::evaluate() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+            "sourceCode:" << sourceCode << " fileName:" << fileName;
+#endif
+        BLOCKING_INVOKE_METHOD(this, "evaluate",
+                                  Q_RETURN_ARG(ScriptValue, result),
+                                  Q_ARG(const QString&, sourceCode),
+                                  Q_ARG(const QString&, fileName));
+        return result;
+    }
+
+    // Check syntax
+    auto syntaxError = lintScript(sourceCode, fileName);
+    if (syntaxError.isError()) {
+        if (!isEvaluating()) {
+            syntaxError.setProperty("detail", "evaluate");
+        }
+        raiseException(syntaxError);
+        maybeEmitUncaughtException("lint");
+        return syntaxError;
+    }
+    QScriptProgram program { sourceCode, fileName, 1 };
+    if (program.isNull()) {
+        // can this happen?
+        auto err = makeError(newValue("could not create QScriptProgram for " + fileName));
+        raiseException(err);
+        maybeEmitUncaughtException("compile");
+        return err;
+    }
+
+    QScriptValue result = QScriptEngine::evaluate(program);
+    maybeEmitUncaughtException("evaluate");
+    
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+Q_INVOKABLE ScriptValue ScriptEngineQtScript::evaluate(const ScriptProgramPointer& program) {
+    if (_scriptManager && _scriptManager->isStopped()) {
+        return undefinedValue(); // bail early
+    }
+
+    if (QThread::currentThread() != QScriptEngine::thread()) {
+        ScriptValue result;
+#ifdef THREAD_DEBUGGING
+        qCDebug(scriptengine) << "*** WARNING *** ScriptEngineQtScript::evaluate() called on wrong thread [" << QThread::currentThread() << "], invoking on correct thread [" << thread() << "] "
+            "sourceCode:" << sourceCode << " fileName:" << fileName;
+#endif
+        BLOCKING_INVOKE_METHOD(this, "evaluate",
+                                  Q_RETURN_ARG(ScriptValue, result),
+                                  Q_ARG(const ScriptProgramPointer&, program));
+        return result;
+    }
+
+    ScriptProgramQtWrapper* unwrapped = ScriptProgramQtWrapper::unwrap(program);
+    if (!unwrapped) {
+        auto err = makeError(newValue("could not unwrap program"));
+        raiseException(err);
+        maybeEmitUncaughtException("compile");
+        return err;
+    }
+
+    const QScriptProgram& qProgram = unwrapped->toQtValue();
+    if (qProgram.isNull()) {
+        // can this happen?
+        auto err = makeError(newValue("requested program is empty"));
+        raiseException(err);
+        maybeEmitUncaughtException("compile");
+        return err;
+    }
+
+    QScriptValue result = QScriptEngine::evaluate(qProgram);
+    maybeEmitUncaughtException("evaluate");
+
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+
+void ScriptEngineQtScript::updateMemoryCost(const qint64& deltaSize) {
+    if (deltaSize > 0) {
+        // We've patched qt to fix https://highfidelity.atlassian.net/browse/BUGZ-46 on mac and windows only.
+#if defined(Q_OS_WIN) || defined(Q_OS_MAC)
+        reportAdditionalMemoryCost(deltaSize);
+#endif
+    }
+}
+
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// ScriptEngine implementation
+
+ScriptValue ScriptEngineQtScript::globalObject() const {
+    QScriptValue global = QScriptEngine::globalObject(); // can't cache the value as it may change
+    return ScriptValue(new ScriptValueQtWrapper(const_cast<ScriptEngineQtScript*>(this), std::move(global)));
+}
+
+ScriptManager* ScriptEngineQtScript::manager() const {
+    return _scriptManager;
+}
+
+ScriptValue ScriptEngineQtScript::newArray(uint length) {
+    QScriptValue result = QScriptEngine::newArray(length);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newArrayBuffer(const QByteArray& message) {
+    QScriptValue data = QScriptEngine::newVariant(QVariant::fromValue(message));
+    QScriptValue ctor = QScriptEngine::globalObject().property("ArrayBuffer");
+    auto array = qscriptvalue_cast<ArrayBufferClass*>(ctor.data());
+    if (!array) {
+        return undefinedValue();
+    }
+    QScriptValue result = QScriptEngine::newObject(array, data);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newObject() {
+    QScriptValue result = QScriptEngine::newObject();
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptProgramPointer ScriptEngineQtScript::newProgram(const QString& sourceCode, const QString& fileName) {
+    QScriptProgram result(sourceCode, fileName);
+    return std::make_shared<ScriptProgramQtWrapper>(this, result);
+}
+
+ScriptValue ScriptEngineQtScript::newQObject(QObject* object,
+                                                    ScriptEngine::ValueOwnership ownership,
+                                                    const ScriptEngine::QObjectWrapOptions& options) {
+    QScriptValue result = ScriptObjectQtProxy::newQObject(this, object, ownership, options);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(bool value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(int value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(uint value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(double value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(const QString& value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(const QLatin1String& value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newValue(const char* value) {
+    QScriptValue result(this, value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::newVariant(const QVariant& value) {
+    QScriptValue result = castVariantToValue(value);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+ScriptValue ScriptEngineQtScript::nullValue() {
+    return _nullValue;
+}
+
+ScriptValue ScriptEngineQtScript::undefinedValue() {
+    return _undefinedValue;
+}
+
+void ScriptEngineQtScript::abortEvaluation() {
+    QScriptEngine::abortEvaluation();
+}
+
+void ScriptEngineQtScript::clearExceptions() {
+    QScriptEngine::clearExceptions();
+}
+
+ScriptContext* ScriptEngineQtScript::currentContext() const {
+    QScriptContext* localCtx = QScriptEngine::currentContext();
+    if (!localCtx) {
+        return nullptr;
+    }
+    if (!_currContext || _currContext->toQtValue() != localCtx) {
+        _currContext = std::make_shared<ScriptContextQtWrapper>(const_cast<ScriptEngineQtScript*>(this), localCtx);
+    }
+    return _currContext.get();
+}
+
+bool ScriptEngineQtScript::hasUncaughtException() const {
+    return QScriptEngine::hasUncaughtException();
+}
+
+bool ScriptEngineQtScript::isEvaluating() const {
+    return QScriptEngine::isEvaluating();
+}
+
+ScriptValue ScriptEngineQtScript::newFunction(ScriptEngine::FunctionSignature fun, int length) {
+    auto innerFunc = [](QScriptContext* _context, QScriptEngine* _engine) -> QScriptValue {
+        auto callee = _context->callee();
+        QVariant funAddr = callee.property("_func").toVariant();
+        ScriptEngine::FunctionSignature fun = reinterpret_cast<ScriptEngine::FunctionSignature>(funAddr.toULongLong());
+        ScriptEngineQtScript* engine = static_cast<ScriptEngineQtScript*>(_engine);
+        ScriptContextQtWrapper context(engine, _context);
+        ScriptValue result = fun(&context, engine);
+        ScriptValueQtWrapper* unwrapped = ScriptValueQtWrapper::unwrap(result);
+        return unwrapped ? unwrapped->toQtValue() : QScriptValue();
+    };
+
+    QScriptValue result = QScriptEngine::newFunction(innerFunc, length);
+    auto funAddr = QScriptEngine::newVariant(QVariant(reinterpret_cast<qulonglong>(fun)));
+    result.setProperty("_func", funAddr, QScriptValue::PropertyFlags(QScriptValue::ReadOnly + QScriptValue::Undeletable + QScriptValue::SkipInEnumeration));
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(result)));
+}
+
+void ScriptEngineQtScript::setObjectName(const QString& name) {
+    QScriptEngine::setObjectName(name);
+}
+
+bool ScriptEngineQtScript::setProperty(const char* name, const QVariant& value) {
+    return QScriptEngine::setProperty(name, value);
+}
+
+void ScriptEngineQtScript::setProcessEventsInterval(int interval) {
+    QScriptEngine::setProcessEventsInterval(interval);
+}
+
+QThread* ScriptEngineQtScript::thread() const {
+    return QScriptEngine::thread();
+}
+
+void ScriptEngineQtScript::setThread(QThread* thread) {
+    moveToThread(thread);
+}
+
+ScriptValue ScriptEngineQtScript::uncaughtException() const {
+    QScriptValue result = QScriptEngine::uncaughtException();
+    return ScriptValue(new ScriptValueQtWrapper(const_cast<ScriptEngineQtScript*>(this), std::move(result)));
+}
+
+QStringList ScriptEngineQtScript::uncaughtExceptionBacktrace() const {
+    return QScriptEngine::uncaughtExceptionBacktrace();
+}
+
+int ScriptEngineQtScript::uncaughtExceptionLineNumber() const {
+    return QScriptEngine::uncaughtExceptionLineNumber();
+}
+
+bool ScriptEngineQtScript::raiseException(const ScriptValue& exception) {
+    ScriptValueQtWrapper* unwrapped = ScriptValueQtWrapper::unwrap(exception);
+    QScriptValue qException = unwrapped ? unwrapped->toQtValue() : QScriptEngine::newVariant(exception.toVariant());
+    return raiseException(qException);
+}
+
+ScriptValue ScriptEngineQtScript::create(int type, const void* ptr) {
+    QVariant variant(type, ptr);
+    QScriptValue scriptValue = castVariantToValue(variant);
+    return ScriptValue(new ScriptValueQtWrapper(this, std::move(scriptValue)));
+}
+
+QVariant ScriptEngineQtScript::convert(const ScriptValue& value, int typeId) {
+    ScriptValueQtWrapper* unwrapped = ScriptValueQtWrapper::unwrap(value);
+    if (unwrapped == nullptr) {
+        return QVariant();
+    }
+
+    QVariant var;
+    if (!castValueToVariant(unwrapped->toQtValue(), var, typeId)) {
+        return QVariant();
+    }
+
+    int destType = var.userType();
+    if (destType != typeId) {
+        var.convert(typeId);  // if conversion fails then var is set to QVariant()
+    }
+
+    return var;
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptEngineQtScript.h b/libraries/script-engine/src/qtscript/ScriptEngineQtScript.h
new file mode 100644
index 00000000000..dcc87207c80
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptEngineQtScript.h
@@ -0,0 +1,215 @@
+//
+//  ScriptEngineQtScript.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Brad Hefta-Gaub on 12/14/13.
+//  Copyright 2013 High Fidelity, Inc.
+//  Copyright 2020 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptEngineQtScript_h
+#define hifi_ScriptEngineQtScript_h
+
+#include <memory>
+
+#include <QtCore/QByteArray>
+#include <QtCore/QHash>
+#include <QtCore/QMetaEnum>
+#include <QtCore/QMutex>
+#include <QtCore/QObject>
+#include <QtCore/QPointer>
+#include <QtCore/QSharedPointer>
+#include <QtCore/QString>
+
+#include <QtScript/QScriptEngine>
+
+#include "../ScriptEngine.h"
+#include "../ScriptManager.h"
+
+#include "ArrayBufferClass.h"
+
+class ScriptContextQtWrapper;
+class ScriptEngineQtScript;
+class ScriptManager;
+class ScriptObjectQtProxy;
+using ScriptContextQtPointer = std::shared_ptr<ScriptContextQtWrapper>;
+
+Q_DECLARE_METATYPE(ScriptEngine::FunctionSignature)
+
+/// [QtScript] Implements ScriptEngine for QtScript and translates calls for QScriptEngine
+class ScriptEngineQtScript final : public QScriptEngine,
+                                   public ScriptEngine,
+                                   public std::enable_shared_from_this<ScriptEngineQtScript> {
+    Q_OBJECT
+
+public:  // construction
+    ScriptEngineQtScript(ScriptManager* scriptManager = nullptr);
+
+    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+    // NOTE - these are NOT intended to be public interfaces available to scripts, the are only Q_INVOKABLE so we can
+    //        properly ensure they are only called on the correct thread
+
+public:  // ScriptEngine implementation
+    virtual void abortEvaluation() override;
+    virtual void clearExceptions() override;
+    virtual ScriptValue cloneUncaughtException(const QString& detail = QString()) override;
+    virtual ScriptContext* currentContext() const override;
+    Q_INVOKABLE virtual ScriptValue evaluate(const QString& program, const QString& fileName = QString()) override;
+    Q_INVOKABLE virtual ScriptValue evaluate(const ScriptProgramPointer& program) override;
+    Q_INVOKABLE virtual ScriptValue evaluateInClosure(const ScriptValue& locals, const ScriptProgramPointer& program) override;
+    virtual ScriptValue globalObject() const override;
+    virtual bool hasUncaughtException() const override;
+    virtual bool isEvaluating() const override;
+    virtual ScriptValue lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber = 1) override;
+    virtual ScriptValue makeError(const ScriptValue& other, const QString& type = "Error") override;
+    virtual ScriptManager* manager() const override;
+
+    // if there is a pending exception and we are at the top level (non-recursive) stack frame, this emits and resets it
+    virtual bool maybeEmitUncaughtException(const QString& debugHint = QString()) override;
+
+    virtual ScriptValue newArray(uint length = 0) override;
+    virtual ScriptValue newArrayBuffer(const QByteArray& message) override;
+    virtual ScriptValue newFunction(ScriptEngine::FunctionSignature fun, int length = 0) override;
+    virtual ScriptValue newObject() override;
+    virtual ScriptProgramPointer newProgram(const QString& sourceCode, const QString& fileName) override;
+    virtual ScriptValue newQObject(QObject *object, ScriptEngine::ValueOwnership ownership = ScriptEngine::QtOwnership,
+        const ScriptEngine::QObjectWrapOptions& options = ScriptEngine::QObjectWrapOptions()) override;
+    virtual ScriptValue newValue(bool value) override;
+    virtual ScriptValue newValue(int value) override;
+    virtual ScriptValue newValue(uint value) override;
+    virtual ScriptValue newValue(double value) override;
+    virtual ScriptValue newValue(const QString& value) override;
+    virtual ScriptValue newValue(const QLatin1String& value) override;
+    virtual ScriptValue newValue(const char* value) override;
+    virtual ScriptValue newVariant(const QVariant& value) override;
+    virtual ScriptValue nullValue() override;
+    virtual bool raiseException(const ScriptValue& exception) override;
+    Q_INVOKABLE virtual void registerEnum(const QString& enumName, QMetaEnum newEnum) override;
+    Q_INVOKABLE virtual void registerFunction(const QString& name,
+                                              ScriptEngine::FunctionSignature fun,
+                                              int numArguments = -1) override;
+    Q_INVOKABLE virtual void registerFunction(const QString& parent,
+                                              const QString& name,
+                                              ScriptEngine::FunctionSignature fun,
+                                              int numArguments = -1) override;
+    Q_INVOKABLE virtual void registerGetterSetter(const QString& name,
+                                                  ScriptEngine::FunctionSignature getter,
+                                                  ScriptEngine::FunctionSignature setter,
+                                                  const QString& parent = QString("")) override;
+    Q_INVOKABLE virtual void registerGlobalObject(const QString& name, QObject* object) override;
+    virtual void setDefaultPrototype(int metaTypeId, const ScriptValue& prototype) override;
+    virtual void setObjectName(const QString& name) override;
+    virtual bool setProperty(const char* name, const QVariant& value) override;
+    virtual void setProcessEventsInterval(int interval) override;
+    virtual QThread* thread() const override;
+    virtual void setThread(QThread* thread) override;
+    virtual ScriptValue undefinedValue() override;
+    virtual ScriptValue uncaughtException() const override;
+    virtual QStringList uncaughtExceptionBacktrace() const override;
+    virtual int uncaughtExceptionLineNumber() const override;
+    virtual void updateMemoryCost(const qint64& deltaSize) override;
+    virtual void requestCollectGarbage() override { collectGarbage(); }
+
+    // helper to detect and log warnings when other code invokes QScriptEngine/BaseScriptEngine in thread-unsafe ways
+    inline bool IS_THREADSAFE_INVOCATION(const QString& method) { return ScriptEngine::IS_THREADSAFE_INVOCATION(method); }
+
+protected: // brought over from BaseScriptEngine
+    QScriptValue makeError(const QScriptValue& other = QScriptValue(), const QString& type = "Error");
+
+    // if the currentContext() is valid then throw the passed exception; otherwise, immediately emit it.
+    // note: this is used in cases where C++ code might call into JS API methods directly
+    bool raiseException(const QScriptValue& exception);
+
+    // helper to detect and log warnings when other code invokes QScriptEngine/BaseScriptEngine in thread-unsafe ways
+    static bool IS_THREADSAFE_INVOCATION(const QThread* thread, const QString& method);
+
+public: // public non-interface methods for other QtScript-specific classes to use
+    /// registers a global getter/setter
+    Q_INVOKABLE void registerGetterSetter(const QString& name, QScriptEngine::FunctionSignature getter,
+                                          QScriptEngine::FunctionSignature setter, const QString& parent = QString(""));
+
+    /// register a global function
+    Q_INVOKABLE void registerFunction(const QString& name, QScriptEngine::FunctionSignature fun, int numArguments = -1);
+
+    /// register a function as a method on a previously registered global object
+    Q_INVOKABLE void registerFunction(const QString& parent, const QString& name, QScriptEngine::FunctionSignature fun,
+                                      int numArguments = -1);
+
+    /// registers a global object by name
+    Q_INVOKABLE void registerValue(const QString& valueName, QScriptValue value);
+
+    // NOTE - this is used by the TypedArray implementation. we need to review this for thread safety
+    inline ArrayBufferClass* getArrayBufferClass() { return _arrayBufferClass; }
+
+public: // not for public use, but I don't like how Qt strings this along with private friend functions
+    virtual ScriptValue create(int type, const void* ptr) override;
+    virtual QVariant convert(const ScriptValue& value, int typeId) override;
+    virtual void registerCustomType(int type, ScriptEngine::MarshalFunction marshalFunc,
+                                    ScriptEngine::DemarshalFunction demarshalFunc) override;
+    bool castValueToVariant(const QScriptValue& val, QVariant& dest, int destTypeId);
+    QScriptValue castVariantToValue(const QVariant& val);
+    static QString valueType(const QScriptValue& val);
+
+    using ObjectWrapperMap = QMap<QObject*, QWeakPointer<ScriptObjectQtProxy>>;
+    mutable QMutex _qobjectWrapperMapProtect;
+    ObjectWrapperMap _qobjectWrapperMap;
+
+protected:
+    // like `newFunction`, but allows mapping inline C++ lambdas with captures as callable QScriptValues
+    // even though the context/engine parameters are redundant in most cases, the function signature matches `newFunction`
+    // anyway so that newLambdaFunction can be used to rapidly prototype / test utility APIs and then if becoming
+    // permanent more easily promoted into regular static newFunction scenarios.
+    QScriptValue newLambdaFunction(std::function<QScriptValue(QScriptContext* context, ScriptEngineQtScript* engine)> operation,
+                                   const QScriptValue& data = QScriptValue(),
+                                   const QScriptEngine::ValueOwnership& ownership = QScriptEngine::AutoOwnership);
+
+    void registerSystemTypes();
+
+protected:
+    struct CustomMarshal {
+        ScriptEngine::MarshalFunction marshalFunc;
+        ScriptEngine::DemarshalFunction demarshalFunc;
+    };
+    using CustomMarshalMap = QHash<int, CustomMarshal>;
+    using CustomPrototypeMap = QHash<int, QScriptValue>;
+
+    QPointer<ScriptManager> _scriptManager;
+
+    mutable QMutex _customTypeProtect;
+    CustomMarshalMap _customTypes;
+    CustomPrototypeMap _customPrototypes;
+    ScriptValue _nullValue;
+    ScriptValue _undefinedValue;
+    mutable ScriptContextQtPointer _currContext;
+
+    ArrayBufferClass* _arrayBufferClass;
+};
+
+// Lambda helps create callable QScriptValues out of std::functions:
+// (just meant for use from within the script engine itself)
+class Lambda : public QObject {
+    Q_OBJECT
+public:
+    Lambda(ScriptEngineQtScript* engine,
+           std::function<QScriptValue(QScriptContext* context, ScriptEngineQtScript* engine)> operation,
+           QScriptValue data);
+    ~Lambda();
+public slots:
+    QScriptValue call();
+    QString toString() const;
+
+private:
+    ScriptEngineQtScript* engine;
+    std::function<QScriptValue(QScriptContext* context, ScriptEngineQtScript* engine)> operation;
+    QScriptValue data;
+};
+
+#endif  // hifi_ScriptEngineQtScript_h
+
+/// @}
diff --git a/libraries/script-engine/src/qtscript/ScriptEngineQtScript_cast.cpp b/libraries/script-engine/src/qtscript/ScriptEngineQtScript_cast.cpp
new file mode 100644
index 00000000000..7b799d168fd
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptEngineQtScript_cast.cpp
@@ -0,0 +1,447 @@
+//
+//  ScriptEngineQtScript_cast.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson 12/9/2021
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptEngineQtScript.h"
+
+#include <QtCore/QJsonArray>
+#include <QtCore/QJsonObject>
+#include <QtCore/QJsonValue>
+#include <QtScript/QScriptEngine>
+
+#include "../ScriptEngineCast.h"
+#include "../ScriptValueIterator.h"
+
+#include "ScriptObjectQtProxy.h"
+#include "ScriptValueQtWrapper.h"
+
+void ScriptEngineQtScript::setDefaultPrototype(int metaTypeId, const ScriptValue& prototype) {
+    ScriptValueQtWrapper* unwrappedPrototype = ScriptValueQtWrapper::unwrap(prototype);
+    if (unwrappedPrototype) {
+        const QScriptValue& scriptPrototype = unwrappedPrototype->toQtValue();
+        QMutexLocker guard(&_customTypeProtect);
+        _customPrototypes.insert(metaTypeId, scriptPrototype);
+    }
+}
+
+void ScriptEngineQtScript::registerCustomType(int type,
+                                              ScriptEngine::MarshalFunction marshalFunc,
+                                              ScriptEngine::DemarshalFunction demarshalFunc)
+{
+    QMutexLocker guard(&_customTypeProtect);
+
+    // storing it in a map for our own benefit
+    CustomMarshal& customType = _customTypes.insert(type, CustomMarshal()).value();
+    customType.demarshalFunc = demarshalFunc;
+    customType.marshalFunc = marshalFunc;
+}
+
+Q_DECLARE_METATYPE(ScriptValue);
+
+static QScriptValue ScriptValueToQScriptValue(QScriptEngine* engine, const ScriptValue& src) {
+    return ScriptValueQtWrapper::fullUnwrap(static_cast<ScriptEngineQtScript*>(engine), src);
+}
+
+static void ScriptValueFromQScriptValue(const QScriptValue& src, ScriptValue& dest) {
+    ScriptEngineQtScript* engine = static_cast<ScriptEngineQtScript*>(src.engine());
+    dest = ScriptValue(new ScriptValueQtWrapper(engine, src));
+}
+
+static ScriptValue StringListToScriptValue(ScriptEngine* engine, const QStringList& src) {
+    int len = src.length();
+    ScriptValue dest = engine->newArray(len);
+    for (int idx = 0; idx < len; ++idx) {
+        dest.setProperty(idx, engine->newValue(src.at(idx)));
+    }
+    return dest;
+}
+
+static bool StringListFromScriptValue(const ScriptValue& src, QStringList& dest) {
+    if(!src.isArray()) return false;
+    int len = src.property("length").toInteger();
+    dest.clear();
+    for (int idx = 0; idx < len; ++idx) {
+        dest.append(src.property(idx).toString());
+    }
+    return true;
+}
+
+static ScriptValue VariantListToScriptValue(ScriptEngine* engine, const QVariantList& src) {
+    int len = src.length();
+    ScriptValue dest = engine->newArray(len);
+    for (int idx = 0; idx < len; ++idx) {
+        dest.setProperty(idx, engine->newVariant(src.at(idx)));
+    }
+    return dest;
+}
+
+static bool VariantListFromScriptValue(const ScriptValue& src, QVariantList& dest) {
+    if(!src.isArray()) return false;
+    int len = src.property("length").toInteger();
+    dest.clear();
+    for (int idx = 0; idx < len; ++idx) {
+        dest.append(src.property(idx).toVariant());
+    }
+    return true;
+}
+
+static ScriptValue VariantMapToScriptValue(ScriptEngine* engine, const QVariantMap& src) {
+    ScriptValue dest = engine->newObject();
+    for (QVariantMap::const_iterator iter = src.cbegin(); iter != src.cend(); ++iter) {
+        dest.setProperty(iter.key(), engine->newVariant(iter.value()));
+    }
+    return dest;
+}
+
+static bool VariantMapFromScriptValue(const ScriptValue& src, QVariantMap& dest) {
+    dest.clear();
+    ScriptValueIteratorPointer iter = src.newIterator();
+    while (iter->hasNext()) {
+        iter->next();
+        dest.insert(iter->name(), iter->value().toVariant());
+    }
+    return true;
+}
+
+static ScriptValue VariantHashToScriptValue(ScriptEngine* engine, const QVariantHash& src) {
+    ScriptValue dest = engine->newObject();
+    for (QVariantHash::const_iterator iter = src.cbegin(); iter != src.cend(); ++iter) {
+        dest.setProperty(iter.key(), engine->newVariant(iter.value()));
+    }
+    return dest;
+}
+
+static bool VariantHashFromScriptValue(const ScriptValue& src, QVariantHash& dest) {
+    dest.clear();
+    ScriptValueIteratorPointer iter = src.newIterator();
+    while (iter->hasNext()) {
+        iter->next();
+        dest.insert(iter->name(), iter->value().toVariant());
+    }
+    return true;
+}
+
+static ScriptValue JsonValueToScriptValue(ScriptEngine* engine, const QJsonValue& src) {
+    return engine->newVariant(src.toVariant());
+}
+
+static bool JsonValueFromScriptValue(const ScriptValue& src, QJsonValue& dest) {
+    dest = QJsonValue::fromVariant(src.toVariant());
+    return true;
+}
+
+static ScriptValue JsonObjectToScriptValue(ScriptEngine* engine, const QJsonObject& src) {
+    QVariantMap map = src.toVariantMap();
+    ScriptValue dest = engine->newObject();
+    for (QVariantMap::const_iterator iter = map.cbegin(); iter != map.cend(); ++iter) {
+        dest.setProperty(iter.key(), engine->newVariant(iter.value()));
+    }
+    return dest;
+}
+
+static bool JsonObjectFromScriptValue(const ScriptValue& src, QJsonObject& dest) {
+    QVariantMap map;
+    ScriptValueIteratorPointer iter = src.newIterator();
+    while (iter->hasNext()) {
+        iter->next();
+        map.insert(iter->name(), iter->value().toVariant());
+    }
+    dest = QJsonObject::fromVariantMap(map);
+    return true;
+}
+
+static ScriptValue JsonArrayToScriptValue(ScriptEngine* engine, const QJsonArray& src) {
+    QVariantList list = src.toVariantList();
+    int len = list.length();
+    ScriptValue dest = engine->newArray(len);
+    for (int idx = 0; idx < len; ++idx) {
+        dest.setProperty(idx, engine->newVariant(list.at(idx)));
+    }
+    return dest;
+}
+
+static bool JsonArrayFromScriptValue(const ScriptValue& src, QJsonArray& dest) {
+    if(!src.isArray()) return false;
+    QVariantList list;
+    int len = src.property("length").toInteger();
+    for (int idx = 0; idx < len; ++idx) {
+        list.append(src.property(idx).toVariant());
+    }
+    dest = QJsonArray::fromVariantList(list);
+    return true;
+}
+
+// QMetaType::QJsonArray
+
+void ScriptEngineQtScript::registerSystemTypes() {
+    qScriptRegisterMetaType(this, ScriptValueToQScriptValue, ScriptValueFromQScriptValue);
+
+    scriptRegisterMetaType(this, StringListToScriptValue, StringListFromScriptValue);
+    scriptRegisterMetaType(this, VariantListToScriptValue, VariantListFromScriptValue);
+    scriptRegisterMetaType(this, VariantMapToScriptValue, VariantMapFromScriptValue);
+    scriptRegisterMetaType(this, VariantHashToScriptValue, VariantHashFromScriptValue);
+    scriptRegisterMetaType(this, JsonValueToScriptValue, JsonValueFromScriptValue);
+    scriptRegisterMetaType(this, JsonObjectToScriptValue, JsonObjectFromScriptValue);
+    scriptRegisterMetaType(this, JsonArrayToScriptValue, JsonArrayFromScriptValue);
+}
+
+bool ScriptEngineQtScript::castValueToVariant(const QScriptValue& val, QVariant& dest, int destTypeId) {
+
+    // if we're not particularly interested in a specific type, try to detect if we're dealing with a registered type
+    if (destTypeId == QMetaType::UnknownType) {
+        QObject* obj = ScriptObjectQtProxy::unwrap(val);
+        if (obj) {
+            for (const QMetaObject* metaObject = obj->metaObject(); metaObject; metaObject = metaObject->superClass()) {
+                QByteArray typeName = QByteArray(metaObject->className()) + "*";
+                int typeId = QMetaType::type(typeName.constData());
+                if (typeId != QMetaType::UnknownType) {
+                    destTypeId = typeId;
+                    break;
+                }
+            }
+        }
+    }
+
+    if (destTypeId == qMetaTypeId<ScriptValue>()) {
+        dest = QVariant::fromValue(ScriptValue(new ScriptValueQtWrapper(this, val)));
+        return true;
+    }
+
+    // do we have a registered handler for this type?
+    ScriptEngine::DemarshalFunction demarshalFunc = nullptr;
+    {
+        QMutexLocker guard(&_customTypeProtect);
+        CustomMarshalMap::const_iterator lookup = _customTypes.find(destTypeId);
+        if (lookup != _customTypes.cend()) {
+            demarshalFunc = lookup.value().demarshalFunc;
+        }
+    }
+    if (demarshalFunc) {
+        dest = QVariant(destTypeId, static_cast<void*>(NULL));
+        ScriptValue wrappedVal(new ScriptValueQtWrapper(this, val));
+        bool success = demarshalFunc(wrappedVal, const_cast<void*>(dest.constData()));
+        if(!success) dest = QVariant();
+        return success;
+    } else {
+        switch (destTypeId) {
+            case QMetaType::UnknownType:
+                if (val.isUndefined()) {
+                    dest = QVariant();
+                    break;
+                }
+                if (val.isNull()) {
+                    dest = QVariant::fromValue(nullptr);
+                    break;
+                }
+                if (val.isBool()) {
+                    dest = QVariant::fromValue(val.toBool());
+                    break;
+                }
+                if (val.isString()) {
+                    dest = QVariant::fromValue(val.toString());
+                    break;
+                }
+                if (val.isNumber()) {
+                    dest = QVariant::fromValue(val.toNumber());
+                    break;
+                }
+                {
+                    QObject* obj = ScriptObjectQtProxy::unwrap(val);
+                    if (obj) {
+                        dest = QVariant::fromValue(obj);
+                        break;
+                    }
+                }
+                {
+                    QVariant var = ScriptVariantQtProxy::unwrap(val);
+                    if (var.isValid()) {
+                        dest = var;
+                        break;
+                    }
+                }
+                dest = val.toVariant();
+                break;
+            case QMetaType::Bool:
+                dest = QVariant::fromValue(val.toBool());
+                break;
+            case QMetaType::QDateTime:
+            case QMetaType::QDate:
+                Q_ASSERT(val.isDate());
+                dest = QVariant::fromValue(val.toDateTime());
+                break;
+            case QMetaType::UInt:
+            case QMetaType::ULong:
+                dest = QVariant::fromValue(val.toUInt32());
+                break;
+            case QMetaType::Int:
+            case QMetaType::Long:
+            case QMetaType::Short:
+                dest = QVariant::fromValue(val.toInt32());
+                break;
+            case QMetaType::Double:
+            case QMetaType::Float:
+            case QMetaType::ULongLong:
+            case QMetaType::LongLong:
+                dest = QVariant::fromValue(val.toNumber());
+                break;
+            case QMetaType::QString:
+            case QMetaType::QByteArray:
+                dest = QVariant::fromValue(val.toString());
+                break;
+            case QMetaType::UShort:
+                dest = QVariant::fromValue(val.toUInt16());
+                break;
+            case QMetaType::QObjectStar:
+                dest = QVariant::fromValue(ScriptObjectQtProxy::unwrap(val));
+                break;
+            default:
+                // check to see if this is a pointer to a QObject-derived object
+                if (QMetaType::typeFlags(destTypeId) & (QMetaType::PointerToQObject | QMetaType::TrackingPointerToQObject)) {
+                    /* Do we really want to permit regular passing of nullptr to native functions?
+                    if (!val.isValid() || val.isUndefined() || val.isNull()) {
+                        dest = QVariant::fromValue(nullptr);
+                        break;
+                    }*/
+                    QObject* obj = ScriptObjectQtProxy::unwrap(val);
+                    if (!obj) return false;
+                    const QMetaObject* destMeta = QMetaType::metaObjectForType(destTypeId);
+                    Q_ASSERT(destMeta);
+                    obj = destMeta->cast(obj);
+                    if (!obj) return false;
+                    dest = QVariant::fromValue(obj);
+                    break;
+                }
+                // check to see if we have a registered prototype
+                {
+                    QVariant var = ScriptVariantQtProxy::unwrap(val);
+                    if (var.isValid()) {
+                        dest = var;
+                        break;
+                    }
+                }
+                // last chance, just convert it to a variant
+                dest = val.toVariant();
+                break;
+        }
+    }
+
+    return destTypeId == QMetaType::UnknownType || dest.userType() == destTypeId || dest.convert(destTypeId);
+}
+
+QString ScriptEngineQtScript::valueType(const QScriptValue& val) {
+    if (val.isUndefined()) {
+        return "undefined";
+    }
+    if (val.isNull()) {
+        return "null";
+    }
+    if (val.isBool()) {
+        return "boolean";
+    }
+    if (val.isString()) {
+        return "string";
+    }
+    if (val.isNumber()) {
+        return "number";
+    }
+    {
+        QObject* obj = ScriptObjectQtProxy::unwrap(val);
+        if (obj) {
+            QString objectName = obj->objectName();
+            if (!objectName.isEmpty()) return objectName;
+            return obj->metaObject()->className();
+        }
+    }
+    {
+        QVariant var = ScriptVariantQtProxy::unwrap(val);
+        if (var.isValid()) {
+            return var.typeName();
+        }
+    }
+    return val.toVariant().typeName();
+}
+
+QScriptValue ScriptEngineQtScript::castVariantToValue(const QVariant& val) {
+    int valTypeId = val.userType();
+
+    if (valTypeId == qMetaTypeId<ScriptValue>()) {
+        // this is a wrapped ScriptValue, so just unwrap it and call it good
+        ScriptValue innerVal = val.value<ScriptValue>();
+        return ScriptValueQtWrapper::fullUnwrap(this, innerVal);
+    }
+
+    // do we have a registered handler for this type?
+    ScriptEngine::MarshalFunction marshalFunc = nullptr;
+    {
+        QMutexLocker guard(&_customTypeProtect);
+        CustomMarshalMap::const_iterator lookup = _customTypes.find(valTypeId);
+        if (lookup != _customTypes.cend()) {
+            marshalFunc = lookup.value().marshalFunc;
+        }
+    }
+    if (marshalFunc) {
+        ScriptValue wrappedVal = marshalFunc(this, val.constData());
+        return ScriptValueQtWrapper::fullUnwrap(this, wrappedVal);
+    }
+
+    switch (valTypeId) {
+        case QMetaType::UnknownType:
+        case QMetaType::Void:
+            return QScriptValue(this, QScriptValue::UndefinedValue);
+        case QMetaType::Nullptr:
+            return QScriptValue(this, QScriptValue::NullValue);
+        case QMetaType::Bool:
+            return QScriptValue(this, val.toBool());
+        case QMetaType::Int:
+        case QMetaType::Long:
+        case QMetaType::Short:
+            return QScriptValue(this, val.toInt());
+        case QMetaType::UInt:
+        case QMetaType::ULong:
+        case QMetaType::UShort:
+            return QScriptValue(this, val.toUInt());
+        case QMetaType::Float:
+        case QMetaType::LongLong:
+        case QMetaType::ULongLong:
+        case QMetaType::Double:
+            return QScriptValue(this, val.toFloat());
+        case QMetaType::QString:
+        case QMetaType::QByteArray:
+            return QScriptValue(this, val.toString());
+        case QMetaType::QVariant:
+            return castVariantToValue(val.value<QVariant>());
+        case QMetaType::QObjectStar: {
+            QObject* obj = val.value<QObject*>();
+            if (obj == nullptr) return QScriptValue(this, QScriptValue::NullValue);
+            return ScriptObjectQtProxy::newQObject(this, obj);
+        }
+        case QMetaType::QDateTime:
+            return static_cast<QScriptEngine*>(this)->newDate(val.value<QDateTime>());
+        case QMetaType::QDate:
+            return static_cast<QScriptEngine*>(this)->newDate(val.value<QDate>().startOfDay());
+        default:
+            // check to see if this is a pointer to a QObject-derived object
+            if (QMetaType::typeFlags(valTypeId) & (QMetaType::PointerToQObject | QMetaType::TrackingPointerToQObject)) {
+                QObject* obj = val.value<QObject*>();
+                if (obj == nullptr) return QScriptValue(this, QScriptValue::NullValue);
+                return ScriptObjectQtProxy::newQObject(this, obj);
+            }
+            // have we set a prototype'd variant?
+            {
+                QMutexLocker guard(&_customTypeProtect);
+                CustomPrototypeMap::const_iterator lookup = _customPrototypes.find(valTypeId);
+                if (lookup != _customPrototypes.cend()) {
+                    return ScriptVariantQtProxy::newVariant(this, val, lookup.value());
+                }
+            }
+            // just do a generic variant
+            return QScriptEngine::newVariant(val);
+    }
+}
\ No newline at end of file
diff --git a/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.cpp b/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.cpp
new file mode 100644
index 00000000000..7f09479ee49
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.cpp
@@ -0,0 +1,731 @@
+//
+//  ScriptObjectQtProxy.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 12/5/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptObjectQtProxy.h"
+
+#include <QtCore/QList>
+#include <QtCore/QSharedPointer>
+
+#include <QtScript/QScriptContext>
+
+#include "ScriptContextQtWrapper.h"
+#include "ScriptValueQtWrapper.h"
+
+Q_DECLARE_METATYPE(QScriptContext*)
+Q_DECLARE_METATYPE(ScriptValue)
+Q_DECLARE_METATYPE(QScriptValue)
+
+Q_DECLARE_METATYPE(QSharedPointer<ScriptObjectQtProxy>)
+Q_DECLARE_METATYPE(QSharedPointer<ScriptVariantQtProxy>)
+
+// Used strictly to replace the "this" object value for property access.  May expand to a full context element
+// if we find it necessary to, but hopefully not needed
+class ScriptPropertyContextQtWrapper final : public ScriptContext {
+public:  // construction
+    inline ScriptPropertyContextQtWrapper(const ScriptValue& object, ScriptContext* parentContext) :
+        _parent(parentContext), _object(object) {}
+
+public:  // ScriptContext implementation
+    virtual int argumentCount() const override { return _parent->argumentCount(); }
+    virtual ScriptValue argument(int index) const override { return _parent->argument(index); }
+    virtual QStringList backtrace() const override { return _parent->backtrace(); }
+    virtual ScriptValue callee() const override { return _parent->callee(); }
+    virtual ScriptEnginePointer engine() const override { return _parent->engine(); }
+    virtual ScriptFunctionContextPointer functionContext() const override { return _parent->functionContext(); }
+    virtual ScriptContextPointer parentContext() const override { return _parent->parentContext(); }
+    virtual ScriptValue thisObject() const override { return _object; }
+    virtual ScriptValue throwError(const QString& text) override { return _parent->throwError(text); }
+    virtual ScriptValue throwValue(const ScriptValue& value) override { return _parent->throwValue(value); }
+
+private:  // storage
+    ScriptContext* _parent;
+    const ScriptValue& _object;
+};
+
+QScriptValue ScriptObjectQtProxy::newQObject(ScriptEngineQtScript* engine, QObject* object,
+                                             ScriptEngine::ValueOwnership ownership,
+                                             const ScriptEngine::QObjectWrapOptions& options) {
+    QScriptEngine* qengine = static_cast<QScriptEngine*>(engine);
+
+    // do we already have a valid wrapper for this QObject?
+    {
+        QMutexLocker guard(&engine->_qobjectWrapperMapProtect);
+        ScriptEngineQtScript::ObjectWrapperMap::const_iterator lookup = engine->_qobjectWrapperMap.find(object);
+        if (lookup != engine->_qobjectWrapperMap.end()) {
+            QSharedPointer<ScriptObjectQtProxy> proxy = lookup.value().lock();
+            if (proxy) return qengine->newObject(proxy.get(), qengine->newVariant(QVariant::fromValue(proxy)));;
+        }
+    }
+    
+    bool ownsObject;
+    switch (ownership) {
+        case ScriptEngine::QtOwnership:
+            ownsObject = false;
+            break;
+        case ScriptEngine::ScriptOwnership:
+            ownsObject = true;
+            break;
+        case ScriptEngine::AutoOwnership:
+            ownsObject = !object->parent();
+            break;
+    }
+
+    // create the wrapper
+    auto proxy = QSharedPointer<ScriptObjectQtProxy>::create(engine, object, ownsObject, options);
+
+    {
+        QMutexLocker guard(&engine->_qobjectWrapperMapProtect);
+
+        // check again to see if someone else created the wrapper while we were busy
+        ScriptEngineQtScript::ObjectWrapperMap::const_iterator lookup = engine->_qobjectWrapperMap.find(object);
+        if (lookup != engine->_qobjectWrapperMap.end()) {
+            QSharedPointer<ScriptObjectQtProxy> proxy = lookup.value().lock();
+            if (proxy) return qengine->newObject(proxy.get(), qengine->newVariant(QVariant::fromValue(proxy)));;
+        }
+
+        // register the wrapper with the engine and make sure it cleans itself up
+        engine->_qobjectWrapperMap.insert(object, proxy);
+        QPointer<ScriptEngineQtScript> enginePtr = engine;
+        object->connect(object, &QObject::destroyed, engine, [enginePtr, object]() {
+            if (!enginePtr) return;
+            QMutexLocker guard(&enginePtr->_qobjectWrapperMapProtect);
+            ScriptEngineQtScript::ObjectWrapperMap::iterator lookup = enginePtr->_qobjectWrapperMap.find(object);
+            if (lookup != enginePtr->_qobjectWrapperMap.end()) {
+                enginePtr->_qobjectWrapperMap.erase(lookup);
+            }
+        });
+    }
+
+    return qengine->newObject(proxy.get(), qengine->newVariant(QVariant::fromValue(proxy)));
+}
+
+ScriptObjectQtProxy* ScriptObjectQtProxy::unwrapProxy(const QScriptValue& val) {
+    QScriptClass* scriptClass = val.scriptClass();
+    return scriptClass ? dynamic_cast<ScriptObjectQtProxy*>(scriptClass) : nullptr;
+}
+
+QObject* ScriptObjectQtProxy::unwrap(const QScriptValue& val) {
+    if (val.isQObject()) {
+        return val.toQObject();
+    }
+    ScriptObjectQtProxy* proxy = unwrapProxy(val);
+    return proxy ? proxy->toQtValue() : nullptr;
+}
+
+ScriptObjectQtProxy::~ScriptObjectQtProxy() {
+    if (_ownsObject) {
+        QObject* qobject = _object;
+        if(qobject) qobject->deleteLater();
+    }
+}
+
+void ScriptObjectQtProxy::investigate() {
+    QObject* qobject = _object;
+    Q_ASSERT(qobject);
+    if (!qobject) return;
+
+    const QMetaObject* metaObject = qobject->metaObject();
+
+    // discover properties
+    int startIdx = _wrapOptions & ScriptEngine::ExcludeSuperClassProperties ? metaObject->propertyOffset() : 0;
+    int num = metaObject->propertyCount();
+    for (int idx = startIdx; idx < num; ++idx) {
+        QMetaProperty prop = metaObject->property(idx);
+        if (!prop.isScriptable()) continue;
+
+        // always exclude child objects (at least until we decide otherwise)
+        int metaTypeId = prop.userType();
+        if (metaTypeId != QMetaType::UnknownType) {
+            QMetaType metaType(metaTypeId);
+            if (metaType.flags() & QMetaType::PointerToQObject) {
+                continue;
+            }
+        }
+
+        PropertyDef& propDef = _props.insert(idx, PropertyDef()).value();
+        propDef.name = _engine->toStringHandle(QString::fromLatin1(prop.name()));
+        propDef.flags = QScriptValue::Undeletable | QScriptValue::PropertyGetter | QScriptValue::PropertySetter |
+                        QScriptValue::QObjectMember;
+        if (prop.isConstant()) propDef.flags |= QScriptValue::ReadOnly;
+    }
+
+    // discover methods
+    startIdx = (_wrapOptions & ScriptEngine::ExcludeSuperClassMethods) ? metaObject->methodOffset() : 0;
+    num = metaObject->methodCount();
+    QHash<QScriptString, int> methodNames;
+    for (int idx = startIdx; idx < num; ++idx) {
+        QMetaMethod method = metaObject->method(idx);
+        
+        // perhaps keep this comment?  Calls (like AudioScriptingInterface::playSound) seem to expect non-public methods to be script-accessible
+        /* if (method.access() != QMetaMethod::Public) continue;*/
+
+        bool isSignal = false;
+        QByteArray szName = method.name();
+
+        switch (method.methodType()) {
+            case QMetaMethod::Constructor:
+                continue;
+            case QMetaMethod::Signal:
+                isSignal = true;
+                break;
+            case QMetaMethod::Slot:
+                if (_wrapOptions & ScriptEngine::ExcludeSlots) {
+                    continue;
+                }
+                if (szName == "deleteLater") {
+                    continue;
+                }
+                break;
+        }
+
+        QScriptString name = _engine->toStringHandle(QString::fromLatin1(szName));
+        auto nameLookup = methodNames.find(name);
+        if (isSignal) {
+            if (nameLookup == methodNames.end()) {
+                SignalDef& signalDef = _signals.insert(idx, SignalDef()).value();
+                signalDef.name = name;
+                signalDef.signal = method;
+                methodNames.insert(name, idx);
+            } else {
+                int originalMethodId = nameLookup.value();
+                SignalDefMap::iterator signalLookup = _signals.find(originalMethodId);
+                Q_ASSERT(signalLookup != _signals.end());
+                SignalDef& signalDef = signalLookup.value();
+                Q_ASSERT(signalDef.signal.parameterCount() != method.parameterCount());
+                if (signalDef.signal.parameterCount() < method.parameterCount()) {
+                    signalDef.signal = method;
+                }
+            }
+        } else {
+            int parameterCount = method.parameterCount();
+            if (nameLookup == methodNames.end()) {
+                MethodDef& methodDef = _methods.insert(idx, MethodDef()).value();
+                methodDef.name = name;
+                methodDef.numMaxParms = parameterCount;
+                methodDef.methods.append(method);
+                methodNames.insert(name, idx);
+            } else {
+                int originalMethodId = nameLookup.value();
+                MethodDefMap::iterator methodLookup = _methods.find(originalMethodId);
+                Q_ASSERT(methodLookup != _methods.end());
+                MethodDef& methodDef = methodLookup.value();
+                if(methodDef.numMaxParms < parameterCount) methodDef.numMaxParms = parameterCount;
+                methodDef.methods.append(method);
+            }
+        }
+    }
+}
+
+QString ScriptObjectQtProxy::name() const {
+    Q_ASSERT(_object);
+    if (!_object) return "";
+    return _object ? _object->objectName() : "";
+    QString objectName = _object->objectName();
+    if (!objectName.isEmpty()) return objectName;
+    return _object->metaObject()->className();
+}
+
+QScriptClass::QueryFlags ScriptObjectQtProxy::queryProperty(const QScriptValue& object, const QScriptString& name, QueryFlags flags, uint* id) {
+    // check for properties
+    for (PropertyDefMap::const_iterator trans = _props.cbegin(); trans != _props.cend(); ++trans) {
+        const PropertyDef& propDef = trans.value();
+        if (propDef.name != name) continue;
+        *id = trans.key() | PROPERTY_TYPE;
+        return flags & (HandlesReadAccess | HandlesWriteAccess);
+    }
+
+    // check for methods
+    for (MethodDefMap::const_iterator trans = _methods.cbegin(); trans != _methods.cend(); ++trans) {
+        if (trans.value().name != name) continue;
+        *id = trans.key() | METHOD_TYPE;
+        return flags & (HandlesReadAccess | HandlesWriteAccess);
+    }
+
+    // check for signals
+    for (SignalDefMap::const_iterator trans = _signals.cbegin(); trans != _signals.cend(); ++trans) {
+        if (trans.value().name != name) continue;
+        *id = trans.key() | SIGNAL_TYPE;
+        return flags & (HandlesReadAccess | HandlesWriteAccess);
+    }
+
+    return QueryFlags();
+}
+
+QScriptValue::PropertyFlags ScriptObjectQtProxy::propertyFlags(const QScriptValue& object, const QScriptString& name, uint id) {
+    QObject* qobject = _object;
+    if (!qobject) {
+        return QScriptValue::PropertyFlags();
+    }
+
+    switch (id & TYPE_MASK) {
+        case PROPERTY_TYPE: {
+            PropertyDefMap::const_iterator lookup = _props.find(id & ~TYPE_MASK);
+            if (lookup == _props.cend()) return QScriptValue::PropertyFlags();
+            const PropertyDef& propDef = lookup.value();
+            return propDef.flags;
+        }
+        case METHOD_TYPE: {
+            MethodDefMap::const_iterator lookup = _methods.find(id & ~TYPE_MASK);
+            if (lookup == _methods.cend()) return QScriptValue::PropertyFlags();
+            return QScriptValue::ReadOnly | QScriptValue::Undeletable | QScriptValue::QObjectMember;
+        }
+        case SIGNAL_TYPE: {
+            SignalDefMap::const_iterator lookup = _signals.find(id & ~TYPE_MASK);
+            if (lookup == _signals.cend()) return QScriptValue::PropertyFlags();
+            return QScriptValue::ReadOnly | QScriptValue::Undeletable | QScriptValue::QObjectMember;
+        }
+    }
+    return QScriptValue::PropertyFlags();
+}
+
+QScriptValue ScriptObjectQtProxy::property(const QScriptValue& object, const QScriptString& name, uint id) {
+    QObject* qobject = _object;
+    if (!qobject) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::ReferenceError, "Referencing deleted native object");
+        return QScriptValue();
+    }
+
+    const QMetaObject* metaObject = qobject->metaObject();
+
+    switch (id & TYPE_MASK) {
+        case PROPERTY_TYPE: {
+            int propId = id & ~TYPE_MASK;
+            PropertyDefMap::const_iterator lookup = _props.find(propId);
+            if (lookup == _props.cend()) return QScriptValue();
+            const PropertyDef& propDef = lookup.value();
+
+            QMetaProperty prop = metaObject->property(propId);
+            ScriptValue scriptThis = ScriptValue(new ScriptValueQtWrapper(_engine, object));
+            ScriptPropertyContextQtWrapper ourContext(scriptThis, _engine->currentContext());
+            ScriptContextGuard guard(&ourContext);
+
+            QVariant varValue = prop.read(qobject);
+            return _engine->castVariantToValue(varValue);
+        }
+        case METHOD_TYPE: {
+            int methodId = id & ~TYPE_MASK;
+            MethodDefMap::const_iterator lookup = _methods.find(methodId);
+            if (lookup == _methods.cend()) return QScriptValue();
+            const MethodDef& methodDef = lookup.value();
+            return static_cast<QScriptEngine*>(_engine)->newObject(
+                new ScriptMethodQtProxy(_engine, qobject, object, methodDef.methods, methodDef.numMaxParms));
+        }
+        case SIGNAL_TYPE: {
+            int signalId = id & ~TYPE_MASK;
+            SignalDefMap::const_iterator defLookup = _signals.find(signalId);
+            if (defLookup == _signals.cend()) return QScriptValue();
+
+            InstanceMap::const_iterator instLookup = _signalInstances.find(signalId);
+            if (instLookup == _signalInstances.cend() || instLookup.value().isNull()) {
+                instLookup = _signalInstances.insert(signalId,
+                    new ScriptSignalQtProxy(_engine, qobject, object, defLookup.value().signal));
+                Q_ASSERT(instLookup != _signalInstances.cend());
+            }
+            ScriptSignalQtProxy* proxy = instLookup.value();
+
+            QScriptEngine::QObjectWrapOptions options = QScriptEngine::ExcludeSuperClassContents |
+                                                        QScriptEngine::ExcludeDeleteLater |
+                                                        QScriptEngine::PreferExistingWrapperObject;
+            return static_cast<QScriptEngine*>(_engine)->newQObject(proxy, QScriptEngine::ScriptOwnership, options);
+        }
+    }
+    return QScriptValue();
+}
+
+void ScriptObjectQtProxy::setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) {
+    if (!(id & PROPERTY_TYPE)) return;
+    QObject* qobject = _object;
+    if (!qobject) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::ReferenceError, "Referencing deleted native object");
+        return;
+    }
+
+    int propId = id & ~TYPE_MASK;
+    PropertyDefMap::const_iterator lookup = _props.find(propId);
+    if (lookup == _props.cend()) return;
+    const PropertyDef& propDef = lookup.value();
+    if (propDef.flags & QScriptValue::ReadOnly) return;
+
+    const QMetaObject* metaObject = qobject->metaObject();
+    QMetaProperty prop = metaObject->property(propId);
+
+    ScriptValue scriptThis = ScriptValue(new ScriptValueQtWrapper(_engine, object));
+    ScriptPropertyContextQtWrapper ourContext(scriptThis, _engine->currentContext());
+    ScriptContextGuard guard(&ourContext);
+
+    int propTypeId = prop.userType();
+    Q_ASSERT(propTypeId != QMetaType::UnknownType);
+    QVariant varValue;
+    if(!_engine->castValueToVariant(value, varValue, propTypeId)) {
+        QByteArray propTypeName = QMetaType(propTypeId).name();
+        QByteArray valTypeName = _engine->valueType(value).toLatin1();
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::TypeError, QString("Cannot convert %1 to %2").arg(valTypeName, propTypeName));
+        return;
+    }
+    prop.write(qobject, varValue);
+}
+
+ScriptVariantQtProxy::ScriptVariantQtProxy(ScriptEngineQtScript* engine, const QVariant& variant, QScriptValue scriptProto, ScriptObjectQtProxy* proto) :
+    QScriptClass(engine), _engine(engine), _variant(variant), _scriptProto(scriptProto), _proto(proto) {
+    _name = QString::fromLatin1(variant.typeName());
+}
+
+QScriptValue ScriptVariantQtProxy::newVariant(ScriptEngineQtScript* engine, const QVariant& variant, QScriptValue proto) {
+    QScriptEngine* qengine = static_cast<QScriptEngine*>(engine);
+    ScriptObjectQtProxy* protoProxy = ScriptObjectQtProxy::unwrapProxy(proto);
+    if (!protoProxy) {
+        Q_ASSERT(protoProxy);
+        return qengine->newVariant(variant);
+    }
+    auto proxy = QSharedPointer<ScriptVariantQtProxy>::create(engine, variant, proto, protoProxy);
+    return qengine->newObject(proxy.get(), qengine->newVariant(QVariant::fromValue(proxy)));
+}
+
+ScriptVariantQtProxy* ScriptVariantQtProxy::unwrapProxy(const QScriptValue& val) {
+    QScriptClass* scriptClass = val.scriptClass();
+    return scriptClass ? dynamic_cast<ScriptVariantQtProxy*>(scriptClass) : nullptr;
+}
+
+QVariant ScriptVariantQtProxy::unwrap(const QScriptValue& val) {
+    ScriptVariantQtProxy* proxy = unwrapProxy(val);
+    return proxy ? proxy->toQtValue() : QVariant();
+}
+
+QString ScriptMethodQtProxy::fullName() const {
+    Q_ASSERT(_object);
+    if (!_object) return "";
+    Q_ASSERT(!_metas.isEmpty());
+    const QMetaMethod& firstMethod = _metas.front();
+    QString objectName = _object->objectName();
+    if (!objectName.isEmpty()) {
+        return QString("%1.%2").arg(objectName, firstMethod.name());
+    }
+    return QString("%1::%2").arg(_object->metaObject()->className(), firstMethod.name());
+}
+
+bool ScriptMethodQtProxy::supportsExtension(Extension extension) const {
+    switch (extension) {
+        case Callable:
+            return true;
+        default:
+            return false;
+    }
+}
+
+QVariant ScriptMethodQtProxy::extension(Extension extension, const QVariant& argument) {
+    if (extension != Callable) return QVariant();
+    QScriptContext* context = qvariant_cast<QScriptContext*>(argument);
+
+    QObject* qobject = _object;
+    if (!qobject) {
+        context->throwError(QScriptContext::ReferenceError, "Referencing deleted native object");
+        return QVariant();
+    }
+
+    int scriptNumArgs = context->argumentCount();
+    int numArgs = std::min(scriptNumArgs, _numMaxParms);
+    
+    const int scriptValueTypeId = qMetaTypeId<ScriptValue>();
+
+    int parameterConversionFailureId = 0;
+    int parameterConversionFailureCount = 0;
+
+    for (auto iter = _metas.cbegin(); iter != _metas.end(); ++iter) {
+        const QMetaMethod& meta = *iter;
+        int methodNumArgs = meta.parameterCount();
+        if (methodNumArgs != numArgs) {
+            continue;
+        }
+
+        QList<ScriptValue> qScriptArgList;
+        QList<QVariant> qVarArgList;
+        QGenericArgument qGenArgs[10];
+        int conversionFailures = 0;
+        for (int arg = 0; arg < numArgs; ++arg) {
+            int methodArgTypeId = meta.parameterType(arg);
+            Q_ASSERT(methodArgTypeId != QMetaType::UnknownType);
+            QScriptValue argVal = context->argument(arg);
+            if (methodArgTypeId == scriptValueTypeId) {
+                qScriptArgList.append(ScriptValue(new ScriptValueQtWrapper(_engine, argVal)));
+                qGenArgs[arg] = Q_ARG(ScriptValue, qScriptArgList.back());
+            } else if (methodArgTypeId == QMetaType::QVariant) {
+                qVarArgList.append(argVal.toVariant());
+                qGenArgs[arg] = Q_ARG(QVariant, qVarArgList.back());
+            } else {
+                QVariant varArgVal;
+                if (!_engine->castValueToVariant(argVal, varArgVal, methodArgTypeId)) {
+                    conversionFailures++;
+                } else {
+                    qVarArgList.append(varArgVal);
+                    const QVariant& converted = qVarArgList.back();
+
+                    // a lot of type conversion assistance thanks to https://stackoverflow.com/questions/28457819/qt-invoke-method-with-qvariant
+                    // A const_cast is needed because calling data() would detach the QVariant.
+                    qGenArgs[arg] =
+                        QGenericArgument(QMetaType::typeName(converted.userType()), const_cast<void*>(converted.constData()));
+                }
+            }
+        }
+        if (conversionFailures) {
+            if (conversionFailures < parameterConversionFailureCount || !parameterConversionFailureCount) {
+                parameterConversionFailureCount = conversionFailures;
+                parameterConversionFailureId = meta.methodIndex();
+            }
+            continue;
+        }
+
+        ScriptContextQtWrapper ourContext(_engine, context);
+        ScriptContextGuard guard(&ourContext);
+
+        int returnTypeId = meta.returnType();
+
+        // The Qt MOC engine will automatically call qRegisterMetaType on invokable parameters and properties, but there's
+        // nothing in there for return values so these need to be explicitly runtime-registered!
+        Q_ASSERT(returnTypeId != QMetaType::UnknownType);
+        if (returnTypeId == QMetaType::UnknownType) {
+            context->throwError(QString("Cannot call native function %1, its return value has not been registered with Qt").arg(fullName()));
+            return QVariant();
+        } else if (returnTypeId == QMetaType::Void) {
+            bool success = meta.invoke(qobject, Qt::DirectConnection, qGenArgs[0], qGenArgs[1], qGenArgs[2], qGenArgs[3],
+                                        qGenArgs[4], qGenArgs[5], qGenArgs[6], qGenArgs[7], qGenArgs[8], qGenArgs[9]);
+            if (!success) {
+                context->throwError(QString("Unexpected: Native call of %1 failed").arg(fullName()));
+            }
+            return QVariant();
+        } else if (returnTypeId == scriptValueTypeId) {
+            ScriptValue result;
+            bool success = meta.invoke(qobject, Qt::DirectConnection, Q_RETURN_ARG(ScriptValue, result), qGenArgs[0],
+                                        qGenArgs[1], qGenArgs[2], qGenArgs[3], qGenArgs[4], qGenArgs[5], qGenArgs[6],
+                                        qGenArgs[7], qGenArgs[8], qGenArgs[9]);
+            if (!success) {
+                context->throwError(QString("Unexpected: Native call of %1 failed").arg(fullName()));
+                return QVariant();
+            }
+            QScriptValue qResult = ScriptValueQtWrapper::fullUnwrap(_engine, result);
+            return QVariant::fromValue(qResult);
+        } else {
+            // a lot of type conversion assistance thanks to https://stackoverflow.com/questions/28457819/qt-invoke-method-with-qvariant
+            const char* typeName = meta.typeName();
+            QVariant qRetVal(returnTypeId, static_cast<void*>(NULL));
+            QGenericReturnArgument sRetVal(typeName, const_cast<void*>(qRetVal.constData()));
+
+            bool success =
+                meta.invoke(qobject, Qt::DirectConnection, sRetVal, qGenArgs[0], qGenArgs[1], qGenArgs[2], qGenArgs[3],
+                            qGenArgs[4], qGenArgs[5], qGenArgs[6], qGenArgs[7], qGenArgs[8], qGenArgs[9]);
+            if (!success) {
+                context->throwError(QString("Unexpected: Native call of %1 failed").arg(fullName()));
+                return QVariant();
+            }
+            QScriptValue qResult = _engine->castVariantToValue(qRetVal);
+            return QVariant::fromValue(qResult);
+        }
+    }
+
+    // we failed to convert the call to C++, try to create a somewhat sane error message
+    if (parameterConversionFailureCount == 0) {
+        context->throwError(QString("Native call of %1 failed: unexpected parameter count").arg(fullName()));
+        return QVariant();
+    }
+
+    const QMetaMethod& meta = _object->metaObject()->method(parameterConversionFailureId);
+    int methodNumArgs = meta.parameterCount();
+    Q_ASSERT(methodNumArgs == numArgs);
+
+    for (int arg = 0; arg < numArgs; ++arg) {
+        int methodArgTypeId = meta.parameterType(arg);
+        Q_ASSERT(methodArgTypeId != QMetaType::UnknownType);
+        QScriptValue argVal = context->argument(arg);
+        if (methodArgTypeId != scriptValueTypeId && methodArgTypeId != QMetaType::QVariant) {
+            QVariant varArgVal;
+            if (!_engine->castValueToVariant(argVal, varArgVal, methodArgTypeId)) {
+                QByteArray methodTypeName = QMetaType(methodArgTypeId).name();
+                QByteArray argTypeName = _engine->valueType(argVal).toLatin1();
+                context->throwError(QScriptContext::TypeError, QString("Native call of %1 failed: Cannot convert parameter %2 from %3 to %4")
+                                                                   .arg(fullName()).arg(arg+1).arg(argTypeName, methodTypeName));
+                return QVariant();
+            }
+        }
+    }
+
+    Q_ASSERT(false); // really shouldn't have gotten here -- it didn't work before and it's working now?
+    return QVariant();
+    context->throwError(QString("Native call of %1 failed: could not locate an overload with the requested arguments").arg(fullName()));
+}
+
+QString ScriptSignalQtProxy::fullName() const {
+    Q_ASSERT(_object);
+    if (!_object) return "";
+    QString objectName = _object->objectName();
+    if (!objectName.isEmpty()) {
+        return QString("%1.%2").arg(objectName, _meta.name());
+    }
+    return QString("%1::%2").arg(_object->metaObject()->className(), _meta.name());
+}
+
+// Adapted from https://doc.qt.io/archives/qq/qq16-dynamicqobject.html, for connecting to a signal without a compile-time definition for it
+int ScriptSignalQtProxy::qt_metacall(QMetaObject::Call call, int id, void** arguments) {
+    id = ScriptSignalQtProxyBase::qt_metacall(call, id, arguments);
+    if (id != 0 || call != QMetaObject::InvokeMetaMethod) {
+        return id;
+    }
+
+    QScriptValueList args;
+    int numArgs = _meta.parameterCount();
+    for (int arg = 0; arg < numArgs; ++arg) {
+        int methodArgTypeId = _meta.parameterType(arg);
+        Q_ASSERT(methodArgTypeId != QMetaType::UnknownType);
+        QVariant argValue(methodArgTypeId, arguments[arg+1]);
+        args.append(_engine->castVariantToValue(argValue));
+    }
+
+    for (ConnectionList::iterator iter = _connections.begin(); iter != _connections.end(); ++iter) {
+        Connection& conn = *iter;
+        conn.callback.call(conn.thisValue, args);
+    }
+
+    return -1;
+}
+
+int ScriptSignalQtProxy::discoverMetaCallIdx() {
+    const QMetaObject* ourMeta = metaObject();
+    return ourMeta->methodCount();
+}
+
+ScriptSignalQtProxy::ConnectionList::iterator ScriptSignalQtProxy::findConnection(QScriptValue thisObject,
+                                                                                  QScriptValue callback) {
+    for (ConnectionList::iterator iter = _connections.begin(); iter != _connections.end(); ++iter) {
+        Connection& conn = *iter;
+        if (conn.callback.strictlyEquals(callback) && conn.thisValue.strictlyEquals(thisObject)) {
+            return iter;
+        }
+    }
+    return _connections.end();
+}
+
+
+void ScriptSignalQtProxy::connect(QScriptValue arg0, QScriptValue arg1) {
+    QObject* qobject = _object;
+    if (!qobject) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::ReferenceError, "Referencing deleted native object");
+        return;
+    }
+
+    // untangle the arguments
+    QScriptValue callback;
+    QScriptValue callbackThis;
+    if (arg1.isFunction()) {
+        callbackThis = arg0;
+        callback = arg1;
+    } else {
+        callback = arg0;
+    }
+    if (!callback.isFunction()) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::TypeError, "Function expected as argument to 'connect'");
+        return;
+    }
+
+    // are we already connected?
+    ConnectionList::iterator lookup = findConnection(callbackThis, callback);
+    if (lookup != _connections.end()) {
+        return; // already exists
+    }
+
+    // add a reference to ourselves to the destination callback
+    QScriptValue destData = callback.data();
+    Q_ASSERT(!destData.isValid() || destData.isArray());
+    if (!destData.isArray()) {
+        destData = static_cast<QScriptEngine*>(_engine)->newArray();
+    }
+    {
+        QScriptValueList args;
+        args << thisObject();
+        destData.property("push").call(destData, args);
+    }
+    callback.setData(destData);
+
+    // add this to our internal list of connections
+    Connection newConn;
+    newConn.callback = callback;
+    newConn.thisValue = callbackThis;
+    _connections.append(newConn);
+
+    // inform Qt that we're connecting to this signal
+    if (!_isConnected) {
+        auto result = QMetaObject::connect(qobject, _meta.methodIndex(), this, _metaCallId);
+        Q_ASSERT(result);
+        _isConnected = true;
+    }
+}
+
+void ScriptSignalQtProxy::disconnect(QScriptValue arg0, QScriptValue arg1) {
+    QObject* qobject = _object;
+    if (!qobject) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::ReferenceError, "Referencing deleted native object");
+        return;
+    }
+
+    // untangle the arguments
+    QScriptValue callback;
+    QScriptValue callbackThis;
+    if (arg1.isFunction()) {
+        callbackThis = arg0;
+        callback = arg1;
+    } else {
+        callback = arg0;
+    }
+    if (!callback.isFunction()) {
+        QScriptContext* currentContext = static_cast<QScriptEngine*>(_engine)->currentContext();
+        currentContext->throwError(QScriptContext::TypeError, "Function expected as argument to 'disconnect'");
+        return;
+    }
+
+    // locate this connection in our list of connections
+    ConnectionList::iterator lookup = findConnection(callbackThis, callback);
+    if (lookup == _connections.end()) {
+        return;  // not here
+    }
+
+    // remove it from our internal list of connections
+    _connections.erase(lookup);
+
+    // remove a reference to ourselves from the destination callback
+    QScriptValue destData = callback.data();
+    Q_ASSERT(destData.isArray());
+    if (destData.isArray()) {
+        QScriptValue qThis = thisObject();
+        int len = destData.property("length").toInteger();
+        bool foundIt = false;
+        for (int idx = 0; idx < len && !foundIt; ++idx) {
+            QScriptValue entry = destData.property(idx);
+            if (entry.strictlyEquals(qThis)) {
+                foundIt = true;
+                QScriptValueList args;
+                args << idx << 1;
+                destData.property("splice").call(destData, args);
+            }
+        }
+        Q_ASSERT(foundIt);
+    }
+
+    // inform Qt that we're no longer connected to this signal
+    if (_connections.empty()) {
+        Q_ASSERT(_isConnected);
+        bool result = QMetaObject::disconnect(qobject, _meta.methodIndex(), this, _metaCallId);
+        Q_ASSERT(result);
+        _isConnected = false;
+    }
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.h b/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.h
new file mode 100644
index 00000000000..34ee8526119
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptObjectQtProxy.h
@@ -0,0 +1,210 @@
+//
+//  ScriptObjectQtProxy.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 12/5/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptObjectQtProxy_h
+#define hifi_ScriptObjectQtProxy_h
+
+#include <QtCore/QHash>
+#include <QtCore/QList>
+#include <QtCore/QPointer>
+#include <QtCore/QString>
+
+#include <QtScript/QScriptable>
+#include <QtScript/QScriptClass>
+#include <QtScript/QScriptString>
+#include <QtScript/QScriptValue>
+
+#include "../ScriptEngine.h"
+#include "ScriptEngineQtScript.h"
+
+class ScriptEngineQtScript;
+class ScriptSignalQtProxy;
+
+/// [QtScript] (re-)implements the translation layer between ScriptValue and QObject.  This object
+/// will focus exclusively on property get/set until function calls appear to be a problem
+class ScriptObjectQtProxy final : public QScriptClass {
+private:  // implementation
+    struct PropertyDef {
+        QScriptString name;
+        QScriptValue::PropertyFlags flags;
+    };
+    struct MethodDef {
+        QScriptString name;
+        int numMaxParms;
+        QList<QMetaMethod> methods;
+    };
+    struct SignalDef {
+        QScriptString name;
+        QMetaMethod signal;
+    };
+    using PropertyDefMap = QHash<uint, PropertyDef>;
+    using MethodDefMap = QHash<uint, MethodDef>;
+    using SignalDefMap = QHash<uint, SignalDef>;
+    using InstanceMap = QHash<uint, QPointer<ScriptSignalQtProxy> >;
+
+    static constexpr uint PROPERTY_TYPE = 0x1000;
+    static constexpr uint METHOD_TYPE = 0x2000;
+    static constexpr uint SIGNAL_TYPE = 0x3000;
+    static constexpr uint TYPE_MASK = 0xF000;
+
+public:  // construction
+    inline ScriptObjectQtProxy(ScriptEngineQtScript* engine, QObject* object, bool ownsObject, const ScriptEngine::QObjectWrapOptions& options) :
+        QScriptClass(engine), _engine(engine), _object(object), _wrapOptions(options), _ownsObject(ownsObject) {
+        investigate();
+    }
+    virtual ~ScriptObjectQtProxy();
+
+    static QScriptValue newQObject(ScriptEngineQtScript* engine,
+                                   QObject* object,
+                                   ScriptEngine::ValueOwnership ownership = ScriptEngine::QtOwnership,
+                                   const ScriptEngine::QObjectWrapOptions& options = ScriptEngine::QObjectWrapOptions());
+    static ScriptObjectQtProxy* unwrapProxy(const QScriptValue& val);
+    static QObject* unwrap(const QScriptValue& val);
+    inline QObject* toQtValue() const { return _object; }
+
+public:  // QScriptClass implementation
+    virtual QString name() const override;
+
+    virtual QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
+    virtual QScriptValue::PropertyFlags propertyFlags(const QScriptValue& object, const QScriptString& name, uint id) override;
+    virtual QueryFlags queryProperty(const QScriptValue& object, const QScriptString& name, QueryFlags flags, uint* id) override;
+    virtual void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
+
+private:  // implementation
+    void investigate();
+
+private:  // storage
+    ScriptEngineQtScript* _engine;
+    const ScriptEngine::QObjectWrapOptions _wrapOptions;
+    PropertyDefMap _props;
+    MethodDefMap _methods;
+    SignalDefMap _signals;
+    InstanceMap _signalInstances;
+    const bool _ownsObject;
+    QPointer<QObject> _object;
+
+    Q_DISABLE_COPY(ScriptObjectQtProxy)
+};
+
+/// [QtScript] (re-)implements the translation layer between ScriptValue and QVariant where a prototype is set.
+/// This object depends on a ScriptObjectQtProxy to provide the prototype's behavior
+class ScriptVariantQtProxy final : public QScriptClass {
+public:  // construction
+    ScriptVariantQtProxy(ScriptEngineQtScript* engine, const QVariant& variant, QScriptValue scriptProto, ScriptObjectQtProxy* proto);
+
+    static QScriptValue newVariant(ScriptEngineQtScript* engine, const QVariant& variant, QScriptValue proto);
+    static ScriptVariantQtProxy* unwrapProxy(const QScriptValue& val);
+    static QVariant unwrap(const QScriptValue& val);
+    inline QVariant toQtValue() const { return _variant; }
+
+public:  // QScriptClass implementation
+    virtual QString name() const override { return _name; }
+
+    virtual QScriptValue prototype() const override { return _scriptProto; }
+
+    virtual QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override {
+        return _proto->property(object, name, id);
+    }
+    virtual QScriptValue::PropertyFlags propertyFlags(const QScriptValue& object, const QScriptString& name, uint id) override {
+        return _proto->propertyFlags(object, name, id);
+    }
+    virtual QueryFlags queryProperty(const QScriptValue& object, const QScriptString& name, QueryFlags flags, uint* id) override {
+        return _proto->queryProperty(object, name, flags, id);
+    }
+    virtual void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override {
+        return _proto->setProperty(object, name, id, value);
+    }
+
+private:  // storage
+    ScriptEngineQtScript* _engine;
+    QVariant _variant;
+    QScriptValue _scriptProto;
+    ScriptObjectQtProxy* _proto;
+    QString _name;
+
+    Q_DISABLE_COPY(ScriptVariantQtProxy)
+};
+
+class ScriptMethodQtProxy final : public QScriptClass {
+public:  // construction
+    inline ScriptMethodQtProxy(ScriptEngineQtScript* engine, QObject* object, QScriptValue lifetime,
+                               const QList<QMetaMethod>& metas, int numMaxParms) :
+        QScriptClass(engine),
+        _engine(engine), _object(object), _objectLifetime(lifetime), _metas(metas), _numMaxParms(numMaxParms) {}
+
+public:  // QScriptClass implementation
+    virtual QString name() const override { return fullName(); }
+    virtual bool supportsExtension(Extension extension) const override;
+    virtual QVariant extension(Extension extension, const QVariant& argument = QVariant()) override;
+
+private:
+    QString fullName() const;
+
+private:  // storage
+    const int _numMaxParms;
+    ScriptEngineQtScript* _engine;
+    QPointer<QObject> _object;
+    QScriptValue _objectLifetime;
+    const QList<QMetaMethod> _metas;
+
+    Q_DISABLE_COPY(ScriptMethodQtProxy)
+};
+
+// This abstract base class serves solely to declare the Q_INVOKABLE methods for ScriptSignalQtProxy
+// as we're overriding qt_metacall later for the signal callback yet still want to support
+// metacalls for the connect/disconnect API
+class ScriptSignalQtProxyBase : public QObject, protected QScriptable {
+    Q_OBJECT
+public:  // API
+    Q_INVOKABLE virtual void connect(QScriptValue arg0, QScriptValue arg1 = QScriptValue()) = 0;
+    Q_INVOKABLE virtual void disconnect(QScriptValue arg0, QScriptValue arg1 = QScriptValue()) = 0;
+};
+
+class ScriptSignalQtProxy final : public ScriptSignalQtProxyBase {
+private:  // storage
+    struct Connection {
+        QScriptValue thisValue;
+        QScriptValue callback;
+    };
+    using ConnectionList = QList<Connection>;
+
+public:  // construction
+    inline ScriptSignalQtProxy(ScriptEngineQtScript* engine, QObject* object, QScriptValue lifetime, const QMetaMethod& meta) :
+        _engine(engine), _object(object), _objectLifetime(lifetime), _meta(meta), _metaCallId(discoverMetaCallIdx()) {}
+
+private:  // implementation
+    virtual int qt_metacall(QMetaObject::Call call, int id, void** arguments);
+    int discoverMetaCallIdx();
+    ConnectionList::iterator findConnection(QScriptValue thisObject, QScriptValue callback);
+    QString fullName() const;
+
+public:  // API
+    virtual void connect(QScriptValue arg0, QScriptValue arg1 = QScriptValue()) override;
+    virtual void disconnect(QScriptValue arg0, QScriptValue arg1 = QScriptValue()) override;
+
+private:  // storage
+    ScriptEngineQtScript* _engine;
+    QPointer<QObject> _object;
+    QScriptValue _objectLifetime;
+    const QMetaMethod _meta;
+    const int _metaCallId;
+    ConnectionList _connections;
+    bool _isConnected{ false };
+
+    Q_DISABLE_COPY(ScriptSignalQtProxy)
+};
+
+#endif  // hifi_ScriptObjectQtProxy_h
+
+/// @}
diff --git a/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.cpp b/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.cpp
new file mode 100644
index 00000000000..3a5b2ae68e6
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.cpp
@@ -0,0 +1,55 @@
+//
+//  ScriptProgramQtWrapper.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 8/24/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptProgramQtWrapper.h"
+
+#include <QtScript/QScriptContext>
+
+#include "ScriptEngineQtScript.h"
+#include "ScriptValueQtWrapper.h"
+
+ScriptProgramQtWrapper* ScriptProgramQtWrapper::unwrap(ScriptProgramPointer val) {
+    if (!val) {
+        return nullptr;
+    }
+
+    return dynamic_cast<ScriptProgramQtWrapper*>(val.get());
+}
+
+ScriptSyntaxCheckResultPointer ScriptProgramQtWrapper::checkSyntax() const {
+    QScriptSyntaxCheckResult result = _engine->checkSyntax(_value.sourceCode());
+    return std::make_shared<ScriptSyntaxCheckResultQtWrapper>(std::move(result));
+}
+
+QString ScriptProgramQtWrapper::fileName() const {
+    return _value.fileName();
+}
+
+QString ScriptProgramQtWrapper::sourceCode() const {
+    return _value.sourceCode();
+}
+
+
+int ScriptSyntaxCheckResultQtWrapper::errorColumnNumber() const {
+    return _value.errorColumnNumber();
+}
+
+int ScriptSyntaxCheckResultQtWrapper::errorLineNumber() const {
+    return _value.errorLineNumber();
+}
+
+QString ScriptSyntaxCheckResultQtWrapper::errorMessage() const {
+    return _value.errorMessage();
+}
+
+ScriptSyntaxCheckResult::State ScriptSyntaxCheckResultQtWrapper::state() const {
+    return static_cast<ScriptSyntaxCheckResult::State>(_value.state());
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.h b/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.h
new file mode 100644
index 00000000000..6849b71339e
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptProgramQtWrapper.h
@@ -0,0 +1,61 @@
+//
+//  ScriptProgramQtWrapper.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 5/21/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptProgramQtWrapper_h
+#define hifi_ScriptProgramQtWrapper_h
+
+#include <QtCore/QPointer>
+#include <QtScript/QScriptProgram>
+
+#include "../ScriptProgram.h"
+#include "ScriptEngineQtScript.h"
+
+/// [QtScript] Implements ScriptProgram for QtScript and translates calls for QScriptProgram
+class ScriptProgramQtWrapper final : public ScriptProgram {
+public: // construction
+    inline ScriptProgramQtWrapper(ScriptEngineQtScript* engine, const QScriptProgram& value) :
+        _engine(engine), _value(value) {}
+    inline ScriptProgramQtWrapper(ScriptEngineQtScript* engine, QScriptProgram&& value) :
+        _engine(engine), _value(std::move(value)) {}
+    static ScriptProgramQtWrapper* unwrap(ScriptProgramPointer val);
+    inline const QScriptProgram& toQtValue() const { return _value; }
+
+public: // ScriptProgram implementation
+    virtual ScriptSyntaxCheckResultPointer checkSyntax() const override;
+    virtual QString fileName() const override;
+    virtual QString sourceCode() const override;
+
+private: // storage
+    QPointer<ScriptEngineQtScript> _engine;
+    QScriptProgram _value;
+};
+
+class ScriptSyntaxCheckResultQtWrapper final : public ScriptSyntaxCheckResult {
+public: // construction
+    inline ScriptSyntaxCheckResultQtWrapper(QScriptSyntaxCheckResult&& value) :
+        _value(std::move(value)) {}
+
+public: // ScriptSyntaxCheckResult implementation
+    virtual int errorColumnNumber() const override;
+    virtual int errorLineNumber() const override;
+    virtual QString errorMessage() const override;
+    virtual State state() const override;
+
+private: // storage
+    QScriptSyntaxCheckResult _value;
+};
+
+#endif  // hifi_ScriptValueQtWrapper_h
+
+/// @}
diff --git a/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.cpp b/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.cpp
new file mode 100644
index 00000000000..ea3a4fe542e
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.cpp
@@ -0,0 +1,33 @@
+//
+//  ScriptValueIteratorQtWrapper.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 8/29/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptValueIteratorQtWrapper.h"
+
+ScriptValue::PropertyFlags ScriptValueIteratorQtWrapper::flags() const {
+    return (ScriptValue::PropertyFlags)(int)_value.flags();
+}
+
+bool ScriptValueIteratorQtWrapper::hasNext() const {
+    return _value.hasNext();
+}
+
+QString ScriptValueIteratorQtWrapper::name() const {
+    return _value.name();
+}
+
+void ScriptValueIteratorQtWrapper::next() {
+    _value.next();
+}
+
+ScriptValue ScriptValueIteratorQtWrapper::value() const {
+    QScriptValue result = _value.value();
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.h b/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.h
new file mode 100644
index 00000000000..00b618c6ded
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptValueIteratorQtWrapper.h
@@ -0,0 +1,47 @@
+//
+//  ScriptValueIteratorQtWrapper.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 8/29/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptValueIteratorQtWrapper_h
+#define hifi_ScriptValueIteratorQtWrapper_h
+
+#include <QtCore/QPointer>
+#include <QtScript/QScriptValueIterator>
+
+#include "../ScriptValueIterator.h"
+#include "ScriptEngineQtScript.h"
+#include "ScriptValueQtWrapper.h"
+
+/// [QtScript] Implements ScriptValueIterator for QtScript and translates calls for QScriptValueIterator
+class ScriptValueIteratorQtWrapper final : public ScriptValueIterator {
+public: // construction
+    inline ScriptValueIteratorQtWrapper(ScriptEngineQtScript* engine, const ScriptValue& object) :
+        _engine(engine), _value(ScriptValueQtWrapper::fullUnwrap(engine, object)) {}
+    inline ScriptValueIteratorQtWrapper(ScriptEngineQtScript* engine, const QScriptValue& object) :
+        _engine(engine), _value(object) {}
+
+public:  // ScriptValueIterator implementation
+    virtual ScriptValue::PropertyFlags flags() const override;
+    virtual bool hasNext() const override;
+    virtual QString name() const override;
+    virtual void next() override;
+    virtual ScriptValue value() const override;
+
+private: // storage
+    QPointer<ScriptEngineQtScript> _engine;
+    QScriptValueIterator _value;
+};
+
+#endif  // hifi_ScriptValueIteratorQtWrapper_h
+
+/// @}
diff --git a/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.cpp b/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.cpp
new file mode 100644
index 00000000000..cae3de30f89
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.cpp
@@ -0,0 +1,234 @@
+//
+//  ScriptValueQtWrapper.cpp
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 5/16/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptValueQtWrapper.h"
+
+#include "ScriptValueIteratorQtWrapper.h"
+
+void ScriptValueQtWrapper::release() {
+    delete this;
+}
+
+ScriptValueProxy* ScriptValueQtWrapper::copy() const {
+    return new ScriptValueQtWrapper(_engine, _value);
+}
+
+ScriptValueQtWrapper* ScriptValueQtWrapper::unwrap(const ScriptValue& val) {
+    return dynamic_cast<ScriptValueQtWrapper*>(val.ptr());
+}
+
+QScriptValue ScriptValueQtWrapper::fullUnwrap(const ScriptValue& value) const {
+    ScriptValueQtWrapper* unwrapped = unwrap(value);
+    if (unwrapped) {
+        if (unwrapped->engine().get() != _engine) {
+            return static_cast<QScriptEngine*>(_engine)->toScriptValue(unwrapped->toVariant());
+        } else {
+            return unwrapped->toQtValue();
+        }
+    }
+    QVariant varValue = value.toVariant();
+    return _engine->castVariantToValue(varValue);
+}
+
+QScriptValue ScriptValueQtWrapper::fullUnwrap(ScriptEngineQtScript* engine, const ScriptValue& value) {
+    ScriptValueQtWrapper* unwrapped = unwrap(value);
+    if (unwrapped) {
+        if (unwrapped->engine().get() != engine) {
+            return static_cast<QScriptEngine*>(engine)->toScriptValue(unwrapped->toVariant());
+        } else {
+            return unwrapped->toQtValue();
+        }
+    }
+    QVariant varValue = value.toVariant();
+    return engine->castVariantToValue(varValue);
+}
+
+ScriptValue ScriptValueQtWrapper::call(const ScriptValue& thisObject, const ScriptValueList& args) {
+    QScriptValue qThis = fullUnwrap(thisObject);
+    QScriptValueList qArgs;
+    for (ScriptValueList::const_iterator iter = args.begin(); iter != args.end(); ++iter) {
+        qArgs.push_back(fullUnwrap(*iter));
+    }
+    QScriptValue result = _value.call(qThis, qArgs);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptValueQtWrapper::call(const ScriptValue& thisObject, const ScriptValue& arguments) {
+    QScriptValue qThis = fullUnwrap(thisObject);
+    QScriptValue qArgs = fullUnwrap(arguments);
+    QScriptValue result = _value.call(qThis, qArgs);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptValueQtWrapper::construct(const ScriptValueList& args) {
+    QScriptValueList qArgs;
+    for (ScriptValueList::const_iterator iter = args.begin(); iter != args.end(); ++iter) {
+        qArgs.push_back(fullUnwrap(*iter));
+    }
+    QScriptValue result = _value.construct(qArgs);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptValueQtWrapper::construct(const ScriptValue& arguments) {
+    QScriptValue unwrapped = fullUnwrap(arguments);
+    QScriptValue result = _value.construct(unwrapped);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptValueQtWrapper::data() const {
+    QScriptValue result = _value.data();
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptEnginePointer ScriptValueQtWrapper::engine() const {
+    if (!_engine) {
+        return ScriptEnginePointer();
+    }
+    return _engine->shared_from_this();
+}
+
+ScriptValueIteratorPointer ScriptValueQtWrapper::newIterator() const {
+    return std::make_shared<ScriptValueIteratorQtWrapper>(_engine, _value);
+}
+
+ScriptValue ScriptValueQtWrapper::property(const QString& name, const ScriptValue::ResolveFlags& mode) const {
+    QScriptValue result = _value.property(name, (QScriptValue::ResolveFlags)(int)mode);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+ScriptValue ScriptValueQtWrapper::property(quint32 arrayIndex, const ScriptValue::ResolveFlags& mode) const {
+    QScriptValue result = _value.property(arrayIndex, (QScriptValue::ResolveFlags)(int)mode);
+    return ScriptValue(new ScriptValueQtWrapper(_engine, std::move(result)));
+}
+
+void ScriptValueQtWrapper::setData(const ScriptValue& value) {
+    QScriptValue unwrapped = fullUnwrap(value);
+    _value.setData(unwrapped);
+}
+
+void ScriptValueQtWrapper::setProperty(const QString& name, const ScriptValue& value, const ScriptValue::PropertyFlags& flags) {
+    QScriptValue unwrapped = fullUnwrap(value);
+    _value.setProperty(name, unwrapped, (QScriptValue::PropertyFlags)(int)flags);
+}
+
+void ScriptValueQtWrapper::setProperty(quint32 arrayIndex, const ScriptValue& value, const ScriptValue::PropertyFlags& flags) {
+    QScriptValue unwrapped = fullUnwrap(value);
+    _value.setProperty(arrayIndex, unwrapped, (QScriptValue::PropertyFlags)(int)flags);
+}
+
+void ScriptValueQtWrapper::setPrototype(const ScriptValue& prototype) {
+    ScriptValueQtWrapper* unwrappedPrototype = unwrap(prototype);
+    if (unwrappedPrototype) {
+        _value.setPrototype(unwrappedPrototype->toQtValue());
+    }
+}
+
+bool ScriptValueQtWrapper::strictlyEquals(const ScriptValue& other) const {
+    ScriptValueQtWrapper* unwrappedOther = unwrap(other);
+    return unwrappedOther ? _value.strictlyEquals(unwrappedOther->toQtValue()) : false;
+}
+
+bool ScriptValueQtWrapper::toBool() const {
+    return _value.toBool();
+}
+
+qint32 ScriptValueQtWrapper::toInt32() const {
+    return _value.toInt32();
+}
+
+double ScriptValueQtWrapper::toInteger() const {
+    return _value.toInteger();
+}
+
+double ScriptValueQtWrapper::toNumber() const {
+    return _value.toNumber();
+}
+
+QString ScriptValueQtWrapper::toString() const {
+    return _value.toString();
+}
+
+quint16 ScriptValueQtWrapper::toUInt16() const {
+    return _value.toUInt16();
+}
+
+quint32 ScriptValueQtWrapper::toUInt32() const {
+    return _value.toUInt32();
+}
+
+QVariant ScriptValueQtWrapper::toVariant() const {
+    QVariant dest;
+    if (_engine->castValueToVariant(_value, dest, QMetaType::UnknownType)) {
+        return dest;
+    } else {
+        Q_ASSERT(false);
+        return QVariant();
+    }
+}
+
+QObject* ScriptValueQtWrapper::toQObject() const {
+    QVariant dest;
+    if (_engine->castValueToVariant(_value, dest, QMetaType::QObjectStar)) {
+        return dest.value<QObject*>();
+    } else {
+        Q_ASSERT(false);
+        return nullptr;
+    }
+}
+
+bool ScriptValueQtWrapper::equals(const ScriptValue& other) const {
+    ScriptValueQtWrapper* unwrappedOther = unwrap(other);
+    return unwrappedOther ? _value.equals(unwrappedOther->toQtValue()) : false;
+}
+
+bool ScriptValueQtWrapper::isArray() const {
+    return _value.isArray();
+}
+
+bool ScriptValueQtWrapper::isBool() const {
+    return _value.isBool();
+}
+
+bool ScriptValueQtWrapper::isError() const {
+    return _value.isError();
+}
+
+bool ScriptValueQtWrapper::isFunction() const {
+    return _value.isFunction();
+}
+
+bool ScriptValueQtWrapper::isNumber() const {
+    return _value.isNumber();
+}
+
+bool ScriptValueQtWrapper::isNull() const {
+    return _value.isNull();
+}
+
+bool ScriptValueQtWrapper::isObject() const {
+    return _value.isObject();
+}
+
+bool ScriptValueQtWrapper::isString() const {
+    return _value.isString();
+}
+
+bool ScriptValueQtWrapper::isUndefined() const {
+    return _value.isUndefined();
+}
+
+bool ScriptValueQtWrapper::isValid() const {
+    return _value.isValid();
+}
+
+bool ScriptValueQtWrapper::isVariant() const {
+    return _value.isVariant();
+}
diff --git a/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.h b/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.h
new file mode 100644
index 00000000000..bce207ddbf1
--- /dev/null
+++ b/libraries/script-engine/src/qtscript/ScriptValueQtWrapper.h
@@ -0,0 +1,96 @@
+//
+//  ScriptValueQtWrapper.h
+//  libraries/script-engine/src/qtscript
+//
+//  Created by Heather Anderson on 5/16/21.
+//  Copyright 2021 Vircadia contributors.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+/// @addtogroup ScriptEngine
+/// @{
+
+#ifndef hifi_ScriptValueQtWrapper_h
+#define hifi_ScriptValueQtWrapper_h
+
+#include <QtCore/QPointer>
+#include <QtScript/QScriptValue>
+
+#include <utility>
+
+#include "../ScriptValue.h"
+#include "ScriptEngineQtScript.h"
+
+/// [QtScript] Implements ScriptValue for QtScript and translates calls for QScriptValue
+class ScriptValueQtWrapper final : public ScriptValueProxy {
+public: // construction
+    inline ScriptValueQtWrapper(ScriptEngineQtScript* engine, const QScriptValue& value) :
+        _engine(engine), _value(value) {}
+    inline ScriptValueQtWrapper(ScriptEngineQtScript* engine, QScriptValue&& value) :
+        _engine(engine), _value(std::move(value)) {}
+    static ScriptValueQtWrapper* unwrap(const ScriptValue& val);
+    inline const QScriptValue& toQtValue() const { return _value; }
+    static QScriptValue fullUnwrap(ScriptEngineQtScript* engine, const ScriptValue& value);
+
+public:
+    virtual void release() override;
+    virtual ScriptValueProxy* copy() const override;
+
+public:  // ScriptValue implementation
+    virtual ScriptValue call(const ScriptValue& thisObject = ScriptValue(),
+                             const ScriptValueList& args = ScriptValueList()) override;
+    virtual ScriptValue call(const ScriptValue& thisObject, const ScriptValue& arguments) override;
+    virtual ScriptValue construct(const ScriptValueList& args = ScriptValueList()) override;
+    virtual ScriptValue construct(const ScriptValue& arguments) override;
+    virtual ScriptValue data() const override;
+    virtual ScriptEnginePointer engine() const override;
+    virtual ScriptValueIteratorPointer newIterator() const override;
+    virtual ScriptValue property(const QString& name,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const override;
+    virtual ScriptValue property(quint32 arrayIndex,
+                                 const ScriptValue::ResolveFlags& mode = ScriptValue::ResolvePrototype) const override;
+    virtual void setData(const ScriptValue& val) override;
+    virtual void setProperty(const QString& name,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) override;
+    virtual void setProperty(quint32 arrayIndex,
+                             const ScriptValue& value,
+                             const ScriptValue::PropertyFlags& flags = ScriptValue::KeepExistingFlags) override;
+    virtual void setPrototype(const ScriptValue& prototype) override;
+    virtual bool strictlyEquals(const ScriptValue& other) const override;
+
+    virtual bool equals(const ScriptValue& other) const override;
+    virtual bool isArray() const override;
+    virtual bool isBool() const override;
+    virtual bool isError() const override;
+    virtual bool isFunction() const override;
+    virtual bool isNumber() const override;
+    virtual bool isNull() const override;
+    virtual bool isObject() const override;
+    virtual bool isString() const override;
+    virtual bool isUndefined() const override;
+    virtual bool isValid() const override;
+    virtual bool isVariant() const override;
+    virtual bool toBool() const override;
+    virtual qint32 toInt32() const override;
+    virtual double toInteger() const override;
+    virtual double toNumber() const override;
+    virtual QString toString() const override;
+    virtual quint16 toUInt16() const override;
+    virtual quint32 toUInt32() const override;
+    virtual QVariant toVariant() const override;
+    virtual QObject* toQObject() const override;
+
+private: // helper functions
+    QScriptValue fullUnwrap(const ScriptValue& value) const;
+
+private: // storage
+    QPointer<ScriptEngineQtScript> _engine;
+    QScriptValue _value;
+};
+
+#endif  // hifi_ScriptValueQtWrapper_h
+
+/// @}
diff --git a/libraries/script-engine/src/TypedArrayPrototype.cpp b/libraries/script-engine/src/qtscript/TypedArrayPrototype.cpp
similarity index 99%
rename from libraries/script-engine/src/TypedArrayPrototype.cpp
rename to libraries/script-engine/src/qtscript/TypedArrayPrototype.cpp
index a1f3ff87e8d..17da12b845c 100644
--- a/libraries/script-engine/src/TypedArrayPrototype.cpp
+++ b/libraries/script-engine/src/qtscript/TypedArrayPrototype.cpp
@@ -11,6 +11,8 @@
 
 #include "TypedArrayPrototype.h"
 
+#include <glm/common.hpp>
+
 #include "TypedArrays.h"
 
 Q_DECLARE_METATYPE(QByteArray*)
diff --git a/libraries/script-engine/src/TypedArrayPrototype.h b/libraries/script-engine/src/qtscript/TypedArrayPrototype.h
similarity index 74%
rename from libraries/script-engine/src/TypedArrayPrototype.h
rename to libraries/script-engine/src/qtscript/TypedArrayPrototype.h
index adcc9f3abf9..ff0ea2fec65 100644
--- a/libraries/script-engine/src/TypedArrayPrototype.h
+++ b/libraries/script-engine/src/qtscript/TypedArrayPrototype.h
@@ -15,9 +15,11 @@
 #ifndef hifi_TypedArrayPrototype_h
 #define hifi_TypedArrayPrototype_h
 
-#include "ArrayBufferViewClass.h"
+#include <QtCore/QObject>
+#include <QtScript/QScriptable>
+#include <QtScript/QScriptValue>
 
-/// The javascript functions associated with a <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></code> instance prototype
+/// [QtScript] The javascript functions associated with a <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></code> instance prototype
 class TypedArrayPrototype : public QObject, public QScriptable {
     Q_OBJECT
 public:
diff --git a/libraries/script-engine/src/TypedArrays.cpp b/libraries/script-engine/src/qtscript/TypedArrays.cpp
similarity index 92%
rename from libraries/script-engine/src/TypedArrays.cpp
rename to libraries/script-engine/src/qtscript/TypedArrays.cpp
index f2c3d3fd3db..8143dfb1fa7 100644
--- a/libraries/script-engine/src/TypedArrays.cpp
+++ b/libraries/script-engine/src/qtscript/TypedArrays.cpp
@@ -13,12 +13,17 @@
 
 #include <glm/glm.hpp>
 
-#include "ScriptEngine.h"
+#include <QtCore/QDataStream>
+
+#include <SharedUtil.h>
+
+#include "ArrayBufferClass.h"
+#include "ScriptEngineQtScript.h"
 #include "TypedArrayPrototype.h"
 
 Q_DECLARE_METATYPE(QByteArray*)
 
-TypedArray::TypedArray(ScriptEngine* scriptEngine, QString name) : ArrayBufferViewClass(scriptEngine) {
+TypedArray::TypedArray(ScriptEngineQtScript* scriptEngine, QString name) : ArrayBufferViewClass(scriptEngine) {
     _bytesPerElementName = engine()->toStringHandle(BYTES_PER_ELEMENT_PROPERTY_NAME.toLatin1());
     _lengthName = engine()->toStringHandle(LENGTH_PROPERTY_NAME.toLatin1());
     _name = engine()->toStringHandle(name.toLatin1());
@@ -229,7 +234,7 @@ void setPropertyHelper(QByteArray* arrayBuffer, const QScriptString& name, uint
     }
 }
 
-Int8ArrayClass::Int8ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, INT_8_ARRAY_CLASS_NAME) {
+Int8ArrayClass::Int8ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, INT_8_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(qint8));
 }
 
@@ -245,7 +250,7 @@ void Int8ArrayClass::setProperty(QScriptValue &object, const QScriptString &name
     setPropertyHelper<qint8>(ba, name, id, value);
 }
 
-Uint8ArrayClass::Uint8ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, UINT_8_ARRAY_CLASS_NAME) {
+Uint8ArrayClass::Uint8ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, UINT_8_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(quint8));
 }
 
@@ -261,7 +266,7 @@ void Uint8ArrayClass::setProperty(QScriptValue& object, const QScriptString& nam
     setPropertyHelper<quint8>(ba, name, id, value);
 }
 
-Uint8ClampedArrayClass::Uint8ClampedArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, UINT_8_CLAMPED_ARRAY_CLASS_NAME) {
+Uint8ClampedArrayClass::Uint8ClampedArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, UINT_8_CLAMPED_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(quint8));
 }
 
@@ -287,7 +292,7 @@ void Uint8ClampedArrayClass::setProperty(QScriptValue& object, const QScriptStri
     }
 }
 
-Int16ArrayClass::Int16ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, INT_16_ARRAY_CLASS_NAME) {
+Int16ArrayClass::Int16ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, INT_16_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(qint16));
 }
 
@@ -303,7 +308,7 @@ void Int16ArrayClass::setProperty(QScriptValue& object, const QScriptString& nam
     setPropertyHelper<qint16>(ba, name, id, value);
 }
 
-Uint16ArrayClass::Uint16ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, UINT_16_ARRAY_CLASS_NAME) {
+Uint16ArrayClass::Uint16ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, UINT_16_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(quint16));
 }
 
@@ -319,7 +324,7 @@ void Uint16ArrayClass::setProperty(QScriptValue& object, const QScriptString& na
     setPropertyHelper<quint16>(ba, name, id, value);
 }
 
-Int32ArrayClass::Int32ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, INT_32_ARRAY_CLASS_NAME) {
+Int32ArrayClass::Int32ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, INT_32_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(qint32));
 }
 
@@ -335,7 +340,7 @@ void Int32ArrayClass::setProperty(QScriptValue& object, const QScriptString& nam
     setPropertyHelper<qint32>(ba, name, id, value);
 }
 
-Uint32ArrayClass::Uint32ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, UINT_32_ARRAY_CLASS_NAME) {
+Uint32ArrayClass::Uint32ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, UINT_32_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(quint32));
 }
 
@@ -352,7 +357,7 @@ void Uint32ArrayClass::setProperty(QScriptValue& object, const QScriptString& na
     setPropertyHelper<quint32>(ba, name, id, value);
 }
 
-Float32ArrayClass::Float32ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, FLOAT_32_ARRAY_CLASS_NAME) {
+Float32ArrayClass::Float32ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, FLOAT_32_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(float));
 }
 
@@ -389,7 +394,7 @@ void Float32ArrayClass::setProperty(QScriptValue& object, const QScriptString& n
     }
 }
 
-Float64ArrayClass::Float64ArrayClass(ScriptEngine* scriptEngine) : TypedArray(scriptEngine, FLOAT_64_ARRAY_CLASS_NAME) {
+Float64ArrayClass::Float64ArrayClass(ScriptEngineQtScript* scriptEngine) : TypedArray(scriptEngine, FLOAT_64_ARRAY_CLASS_NAME) {
     setBytesPerElement(sizeof(double));
 }
 
diff --git a/libraries/script-engine/src/TypedArrays.h b/libraries/script-engine/src/qtscript/TypedArrays.h
similarity index 86%
rename from libraries/script-engine/src/TypedArrays.h
rename to libraries/script-engine/src/qtscript/TypedArrays.h
index 948b9677f14..0595ba3c630 100644
--- a/libraries/script-engine/src/TypedArrays.h
+++ b/libraries/script-engine/src/qtscript/TypedArrays.h
@@ -30,11 +30,11 @@ static const QString UINT_32_ARRAY_CLASS_NAME = "Uint32Array";
 static const QString FLOAT_32_ARRAY_CLASS_NAME = "Float32Array";
 static const QString FLOAT_64_ARRAY_CLASS_NAME = "Float64Array";
 
-/// Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></code> scripting class
+/// [QtScript] Implements the <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray">TypedArray</a></code> scripting class
 class TypedArray : public ArrayBufferViewClass {
     Q_OBJECT
 public:
-    TypedArray(ScriptEngine* scriptEngine, QString name);
+    TypedArray(ScriptEngineQtScript* scriptEngine, QString name);
     virtual QScriptValue newInstance(quint32 length);
     virtual QScriptValue newInstance(QScriptValue array);
     virtual QScriptValue newInstance(QScriptValue buffer, quint32 byteOffset, quint32 length);
@@ -71,7 +71,7 @@ class TypedArray : public ArrayBufferViewClass {
 class Int8ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Int8ArrayClass(ScriptEngine* scriptEngine);
+    Int8ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -80,7 +80,7 @@ class Int8ArrayClass : public TypedArray {
 class Uint8ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Uint8ArrayClass(ScriptEngine* scriptEngine);
+    Uint8ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -89,7 +89,7 @@ class Uint8ArrayClass : public TypedArray {
 class Uint8ClampedArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Uint8ClampedArrayClass(ScriptEngine* scriptEngine);
+    Uint8ClampedArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -98,7 +98,7 @@ class Uint8ClampedArrayClass : public TypedArray {
 class Int16ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Int16ArrayClass(ScriptEngine* scriptEngine);
+    Int16ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -107,7 +107,7 @@ class Int16ArrayClass : public TypedArray {
 class Uint16ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Uint16ArrayClass(ScriptEngine* scriptEngine);
+    Uint16ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -116,7 +116,7 @@ class Uint16ArrayClass : public TypedArray {
 class Int32ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Int32ArrayClass(ScriptEngine* scriptEngine);
+    Int32ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -125,7 +125,7 @@ class Int32ArrayClass : public TypedArray {
 class Uint32ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Uint32ArrayClass(ScriptEngine* scriptEngine);
+    Uint32ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -134,7 +134,7 @@ class Uint32ArrayClass : public TypedArray {
 class Float32ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Float32ArrayClass(ScriptEngine* scriptEngine);
+    Float32ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
@@ -143,7 +143,7 @@ class Float32ArrayClass : public TypedArray {
 class Float64ArrayClass : public TypedArray {
     Q_OBJECT
 public:
-    Float64ArrayClass(ScriptEngine* scriptEngine);
+    Float64ArrayClass(ScriptEngineQtScript* scriptEngine);
 
     QScriptValue property(const QScriptValue& object, const QScriptString& name, uint id) override;
     void setProperty(QScriptValue& object, const QScriptString& name, uint id, const QScriptValue& value) override;
diff --git a/libraries/shared/CMakeLists.txt b/libraries/shared/CMakeLists.txt
index 59fb4d81abe..7e3be4c2292 100644
--- a/libraries/shared/CMakeLists.txt
+++ b/libraries/shared/CMakeLists.txt
@@ -3,7 +3,7 @@ set(TARGET_NAME shared)
 include_directories("${QT_DIR}/include/QtCore/${QT_VERSION}/QtCore" "${QT_DIR}/include/QtCore/${QT_VERSION}")
 
 # TODO: there isn't really a good reason to have Script linked here - let's get what is requiring it out (RegisteredMetaTypes.cpp)
-setup_hifi_library(Gui Network Script)
+setup_hifi_library(Gui Network)
 
 if (WIN32)
     target_link_libraries(${TARGET_NAME} Wbemuuid.lib)
diff --git a/libraries/shared/src/BaseScriptEngine.cpp b/libraries/shared/src/BaseScriptEngine.cpp
deleted file mode 100644
index 22ae01d72f0..00000000000
--- a/libraries/shared/src/BaseScriptEngine.cpp
+++ /dev/null
@@ -1,367 +0,0 @@
-//
-//  BaseScriptEngine.cpp
-//  libraries/script-engine/src
-//
-//  Created by Timothy Dedischew on 02/01/17.
-//  Copyright 2017 High Fidelity, Inc.
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#include "BaseScriptEngine.h"
-#include "SharedLogging.h"
-
-#include <QtCore/QString>
-#include <QtCore/QThread>
-#include <QtCore/QUrl>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptValueIterator>
-#include <QtScript/QScriptContextInfo>
-
-#include "Profile.h"
-
-const QString BaseScriptEngine::SCRIPT_EXCEPTION_FORMAT { "[%0] %1 in %2:%3" };
-const QString BaseScriptEngine::SCRIPT_BACKTRACE_SEP { "\n    " };
-
-bool BaseScriptEngine::IS_THREADSAFE_INVOCATION(const QThread *thread, const QString& method) {
-    if (QThread::currentThread() == thread) {
-        return true;
-    }
-    qCCritical(shared) << QString("Scripting::%1 @ %2 -- ignoring thread-unsafe call from %3")
-        .arg(method).arg(thread ? thread->objectName() : "(!thread)").arg(QThread::currentThread()->objectName());
-    qCDebug(shared) << "(please resolve on the calling side by using invokeMethod, executeOnScriptThread, etc.)";
-    Q_ASSERT(false);
-    return false;
-}
-
-// engine-aware JS Error copier and factory
-QScriptValue BaseScriptEngine::makeError(const QScriptValue& _other, const QString& type) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-    auto other = _other;
-    if (other.isString()) {
-        other = newObject();
-        other.setProperty("message", _other.toString());
-    }
-    auto proto = globalObject().property(type);
-    if (!proto.isFunction()) {
-        proto = globalObject().property(other.prototype().property("constructor").property("name").toString());
-    }
-    if (!proto.isFunction()) {
-#ifdef DEBUG_JS_EXCEPTIONS
-        qCDebug(shared) << "BaseScriptEngine::makeError -- couldn't find constructor for" << type << " -- using Error instead";
-#endif
-        proto = globalObject().property("Error");
-    }
-    if (other.engine() != this) {
-        // JS Objects are parented to a specific script engine instance
-        // -- this effectively ~clones it locally by routing through a QVariant and back
-        other = toScriptValue(other.toVariant());
-    }
-    // ~ var err = new Error(other.message)
-    auto err = proto.construct(QScriptValueList({other.property("message")}));
-
-    // transfer over any existing properties
-    QScriptValueIterator it(other);
-    while (it.hasNext()) {
-        it.next();
-        err.setProperty(it.name(), it.value());
-    }
-    return err;
-}
-
-// check syntax and when there are issues returns an actual "SyntaxError" with the details
-QScriptValue BaseScriptEngine::lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-    const auto syntaxCheck = checkSyntax(sourceCode);
-    if (syntaxCheck.state() != QScriptSyntaxCheckResult::Valid) {
-        auto err = globalObject().property("SyntaxError")
-            .construct(QScriptValueList({syntaxCheck.errorMessage()}));
-        err.setProperty("fileName", fileName);
-        err.setProperty("lineNumber", syntaxCheck.errorLineNumber());
-        err.setProperty("expressionBeginOffset", syntaxCheck.errorColumnNumber());
-        err.setProperty("stack", currentContext()->backtrace().join(SCRIPT_BACKTRACE_SEP));
-        {
-            const auto error = syntaxCheck.errorMessage();
-            const auto line = QString::number(syntaxCheck.errorLineNumber());
-            const auto column = QString::number(syntaxCheck.errorColumnNumber());
-            // for compatibility with legacy reporting
-            const auto message = QString("[SyntaxError] %1 in %2:%3(%4)").arg(error, fileName, line, column);
-            err.setProperty("formatted", message);
-        }
-        return err;
-    }
-    return QScriptValue();
-}
-
-// this pulls from the best available information to create a detailed snapshot of the current exception
-QScriptValue BaseScriptEngine::cloneUncaughtException(const QString& extraDetail) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-    if (!hasUncaughtException()) {
-        return unboundNullValue();
-    }
-    auto exception = uncaughtException();
-    // ensure the error object is engine-local
-    auto err = makeError(exception);
-
-    // not sure why Qt does't offer uncaughtExceptionFileName -- but the line number
-    // on its own is often useless/wrong if arbitrarily married to a filename.
-    // when the error object already has this info, it seems to be the most reliable
-    auto fileName = exception.property("fileName").toString();
-    auto lineNumber = exception.property("lineNumber").toInt32();
-
-    // the backtrace, on the other hand, seems most reliable taken from uncaughtExceptionBacktrace
-    auto backtrace = uncaughtExceptionBacktrace();
-    if (backtrace.isEmpty()) {
-        // fallback to the error object
-        backtrace = exception.property("stack").toString().split(SCRIPT_BACKTRACE_SEP);
-    }
-    // the ad hoc "detail" property can be used now to embed additional clues
-    auto detail = exception.property("detail").toString();
-    if (detail.isEmpty()) {
-        detail = extraDetail;
-    } else if (!extraDetail.isEmpty()) {
-        detail += "(" + extraDetail + ")";
-    }
-    if (lineNumber <= 0) {
-        lineNumber = uncaughtExceptionLineNumber();
-    }
-    if (fileName.isEmpty()) {
-        // climb the stack frames looking for something useful to display
-        for (auto c = currentContext(); c && fileName.isEmpty(); c = c->parentContext()) {
-            QScriptContextInfo info { c };
-            if (!info.fileName().isEmpty()) {
-                // take fileName:lineNumber as a pair
-                fileName = info.fileName();
-                lineNumber = info.lineNumber();
-                if (backtrace.isEmpty()) {
-                    backtrace = c->backtrace();
-                }
-                break;
-            }
-        }
-    }
-    err.setProperty("fileName", fileName);
-    err.setProperty("lineNumber", lineNumber );
-    err.setProperty("detail", detail);
-    err.setProperty("stack", backtrace.join(SCRIPT_BACKTRACE_SEP));
-
-#ifdef DEBUG_JS_EXCEPTIONS
-    err.setProperty("_fileName", exception.property("fileName").toString());
-    err.setProperty("_stack", uncaughtExceptionBacktrace().join(SCRIPT_BACKTRACE_SEP));
-    err.setProperty("_lineNumber", uncaughtExceptionLineNumber());
-#endif
-    return err;
-}
-
-QString BaseScriptEngine::formatException(const QScriptValue& exception, bool includeExtendedDetails) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return QString();
-    }
-    QString note { "UncaughtException" };
-    QString result;
-
-    if (!exception.isObject()) {
-        return result;
-    }
-    const auto message = exception.toString();
-    const auto fileName = exception.property("fileName").toString();
-    const auto lineNumber = exception.property("lineNumber").toString();
-    const auto stacktrace =  exception.property("stack").toString();
-
-    if (includeExtendedDetails) {
-        // Display additional exception / troubleshooting hints that can be added via the custom Error .detail property
-        // Example difference:
-        //   [UncaughtExceptions] Error: Can't find variable: foobar in atp:/myentity.js\n...
-        //   [UncaughtException (construct {1eb5d3fa-23b1-411c-af83-163af7220e3f})] Error: Can't find variable: foobar in atp:/myentity.js\n...
-        if (exception.property("detail").isValid()) {
-            note += " " + exception.property("detail").toString();
-        }
-    }
-
-    result = QString(SCRIPT_EXCEPTION_FORMAT).arg(note, message, fileName, lineNumber);
-    if (!stacktrace.isEmpty()) {
-        result += QString("\n[Backtrace]%1%2").arg(SCRIPT_BACKTRACE_SEP).arg(stacktrace);
-    }
-    return result;
-}
-
-bool BaseScriptEngine::raiseException(const QScriptValue& exception) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return false;
-    }
-    if (currentContext()) {
-        // we have an active context / JS stack frame so throw the exception per usual
-        currentContext()->throwValue(makeError(exception));
-        return true;
-    } else {
-        // we are within a pure C++ stack frame (ie: being called directly by other C++ code)
-        // in this case no context information is available so just emit the exception for reporting
-        emit unhandledException(makeError(exception));
-    }
-    return false;
-}
-
-bool BaseScriptEngine::maybeEmitUncaughtException(const QString& debugHint) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return false;
-    }
-    if (!isEvaluating() && hasUncaughtException()) {
-        emit unhandledException(cloneUncaughtException(debugHint));
-        clearExceptions();
-        return true;
-    }
-    return false;
-}
-
-QScriptValue BaseScriptEngine::evaluateInClosure(const QScriptValue& closure, const QScriptProgram& program) {
-    PROFILE_RANGE(script, "evaluateInClosure");
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return unboundNullValue();
-    }
-    const auto fileName = program.fileName();
-    const auto shortName = QUrl(fileName).fileName();
-
-    QScriptValue result;
-    QScriptValue oldGlobal;
-    auto global = closure.property("global");
-    if (global.isObject()) {
-#ifdef DEBUG_JS
-        qCDebug(shared) << " setting global = closure.global" << shortName;
-#endif
-        oldGlobal = globalObject();
-        setGlobalObject(global);
-    }
-
-    auto context = pushContext();
-
-    auto thiz = closure.property("this");
-    if (thiz.isObject()) {
-#ifdef DEBUG_JS
-        qCDebug(shared) << " setting this = closure.this" << shortName;
-#endif
-        context->setThisObject(thiz);
-    }
-
-    context->pushScope(closure);
-#ifdef DEBUG_JS
-    qCDebug(shared) << QString("[%1] evaluateInClosure %2").arg(isEvaluating()).arg(shortName);
-#endif
-    {
-        result = BaseScriptEngine::evaluate(program);
-        if (hasUncaughtException()) {
-            auto err = cloneUncaughtException(__FUNCTION__);
-#ifdef DEBUG_JS_EXCEPTIONS
-            qCWarning(shared) << __FUNCTION__ << "---------- hasCaught:" << err.toString() << result.toString();
-            err.setProperty("_result", result);
-#endif
-            result = err;
-        }
-    }
-#ifdef DEBUG_JS
-    qCDebug(shared) << QString("[%1] //evaluateInClosure %2").arg(isEvaluating()).arg(shortName);
-#endif
-    popContext();
-
-    if (oldGlobal.isValid()) {
-#ifdef DEBUG_JS
-        qCDebug(shared) << " restoring global" << shortName;
-#endif
-        setGlobalObject(oldGlobal);
-    }
-
-    return result;
-}
-
-// Lambda
-QScriptValue BaseScriptEngine::newLambdaFunction(std::function<QScriptValue(QScriptContext *, QScriptEngine*)> operation, const QScriptValue& data, const QScriptEngine::ValueOwnership& ownership) {
-    auto lambda = new Lambda(this, operation, data);
-    auto object = newQObject(lambda, ownership);
-    auto call = object.property("call");
-    call.setPrototype(object); // context->callee().prototype() === Lambda QObject
-    call.setData(data);        // context->callee().data() will === data param
-    return call;
-}
-QString Lambda::toString() const {
-    return QString("[Lambda%1]").arg(data.isValid() ? " " + data.toString() : data.toString());
-}
-
-Lambda::~Lambda() {
-#ifdef DEBUG_JS_LAMBDA_FUNCS
-    qDebug() << "~Lambda" << "this" << this;
-#endif
-}
-
-Lambda::Lambda(QScriptEngine *engine, std::function<QScriptValue(QScriptContext *, QScriptEngine*)> operation, QScriptValue data)
-    : engine(engine), operation(operation), data(data) {
-#ifdef DEBUG_JS_LAMBDA_FUNCS
-    qDebug() << "Lambda" << data.toString();
-#endif
-}
-QScriptValue Lambda::call() {
-    if (!BaseScriptEngine::IS_THREADSAFE_INVOCATION(engine->thread(), __FUNCTION__)) {
-        return BaseScriptEngine::unboundNullValue();
-    }
-    return operation(engine->currentContext(), engine);
-}
-
-QScriptValue makeScopedHandlerObject(QScriptValue scopeOrCallback, QScriptValue methodOrName) {
-    auto engine = scopeOrCallback.engine();
-    if (!engine) {
-        return scopeOrCallback;
-    }
-    auto scope = QScriptValue();
-    auto callback = scopeOrCallback;
-    if (scopeOrCallback.isObject()) {
-        if (methodOrName.isString()) {
-            scope = scopeOrCallback;
-            callback = scope.property(methodOrName.toString());
-        } else if (methodOrName.isFunction()) {
-            scope = scopeOrCallback;
-            callback = methodOrName;
-        } else if (!methodOrName.isValid()) {
-            // instantiate from an existing scoped handler object
-            if (scopeOrCallback.property("callback").isFunction()) {
-                scope = scopeOrCallback.property("scope");
-                callback = scopeOrCallback.property("callback");
-            }
-        }
-    }
-    auto handler = engine->newObject();
-    handler.setProperty("scope", scope);
-    handler.setProperty("callback", callback);
-    return handler;
-}
-
-QScriptValue callScopedHandlerObject(QScriptValue handler, QScriptValue err, QScriptValue result) {
-    return handler.property("callback").call(handler.property("scope"), QScriptValueList({ err, result }));
-}
-
-#ifdef DEBUG_JS
-void BaseScriptEngine::_debugDump(const QString& header, const QScriptValue& object, const QString& footer) {
-    if (!IS_THREADSAFE_INVOCATION(thread(), __FUNCTION__)) {
-        return;
-    }
-    if (!header.isEmpty()) {
-        qCDebug(shared) << header;
-    }
-    if (!object.isObject()) {
-        qCDebug(shared) << "(!isObject)" << object.toVariant().toString() << object.toString();
-        return;
-    }
-    QScriptValueIterator it(object);
-    while (it.hasNext()) {
-        it.next();
-        qCDebug(shared) << it.name() << ":" << it.value().toString();
-    }
-    if (!footer.isEmpty()) {
-        qCDebug(shared) << footer;
-    }
-}
-#endif
diff --git a/libraries/shared/src/BaseScriptEngine.h b/libraries/shared/src/BaseScriptEngine.h
deleted file mode 100644
index 73914dc6899..00000000000
--- a/libraries/shared/src/BaseScriptEngine.h
+++ /dev/null
@@ -1,137 +0,0 @@
-//
-//  BaseScriptEngine.h
-//  libraries/script-engine/src
-//
-//  Created by Timothy Dedischew on 02/01/17.
-//  Copyright 2017 High Fidelity, Inc.
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#ifndef hifi_BaseScriptEngine_h
-#define hifi_BaseScriptEngine_h
-
-#include <functional>
-#include <QtCore/QDebug>
-#include <QtCore/QSharedPointer>
-#include <QtScript/QScriptEngine>
-
-class ScriptEngine;
-using ScriptEnginePointer = QSharedPointer<ScriptEngine>;
-
-// common base class for extending QScriptEngine itself
-class BaseScriptEngine : public QScriptEngine, public QEnableSharedFromThis<BaseScriptEngine> {
-    Q_OBJECT
-public:
-    static const QString SCRIPT_EXCEPTION_FORMAT;
-    static const QString SCRIPT_BACKTRACE_SEP;
-
-    // threadsafe "unbound" version of QScriptEngine::nullValue()
-    static const QScriptValue unboundNullValue() { return QScriptValue(0, QScriptValue::NullValue); }
-
-    BaseScriptEngine() {}
-
-    /*@jsdoc
-     * @function Script.lintScript
-     * @param {string} sourceCode - Source code.
-     * @param {string} fileName - File name.
-     * @param {number} [lineNumber=1] - Line number.
-     * @returns {object} Object.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE QScriptValue lintScript(const QString& sourceCode, const QString& fileName, const int lineNumber = 1);
-
-    /*@jsdoc
-     * @function Script.makeError
-     * @param {object} [other] - Other.
-     * @param {string} [type="Error"] - Error.
-     * @returns {object} Object.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE QScriptValue makeError(const QScriptValue& other = QScriptValue(), const QString& type = "Error");
-    
-    /*@jsdoc
-     * @function Script.formatExecption
-     * @param {object} exception - Exception.
-     * @param {boolean} inludeExtendeDetails - Include extended details.
-     * @returns {string} String.
-     * @deprecated This function is deprecated and will be removed.
-     */
-    Q_INVOKABLE QString formatException(const QScriptValue& exception, bool includeExtendedDetails);
-
-    QScriptValue cloneUncaughtException(const QString& detail = QString());
-    QScriptValue evaluateInClosure(const QScriptValue& locals, const QScriptProgram& program);
-
-    // if there is a pending exception and we are at the top level (non-recursive) stack frame, this emits and resets it
-    bool maybeEmitUncaughtException(const QString& debugHint = QString());
-
-    // if the currentContext() is valid then throw the passed exception; otherwise, immediately emit it.
-    // note: this is used in cases where C++ code might call into JS API methods directly
-    bool raiseException(const QScriptValue& exception);
-
-    // helper to detect and log warnings when other code invokes QScriptEngine/BaseScriptEngine in thread-unsafe ways
-    static bool IS_THREADSAFE_INVOCATION(const QThread *thread, const QString& method);
-signals:
-    /*@jsdoc
-     * @function Script.signalHandlerException
-     * @param {object} exception - Exception.
-     * @returns {Signal}
-     * @deprecated This signal is deprecated and will be removed.
-     */
-    // Script.signalHandlerException is exposed by QScriptEngine.
-    
-    /*@jsdoc
-     * Triggered when a script generates an unhandled exception.
-     * @function Script.unhandledException
-     * @param {object} exception - The details of the exception.
-     * @returns {Signal}
-     * @example <caption>Report the details of an unhandled exception.</caption>
-     * Script.unhandledException.connect(function (exception) {
-     *     print("Unhandled exception: " + JSON.stringify(exception));
-     * });
-     * var properties = JSON.parse("{ x: 1"); // Invalid JSON string.
-     */
-    void unhandledException(const QScriptValue& exception);
-
-protected:
-    // like `newFunction`, but allows mapping inline C++ lambdas with captures as callable QScriptValues
-    // even though the context/engine parameters are redundant in most cases, the function signature matches `newFunction`
-    // anyway so that newLambdaFunction can be used to rapidly prototype / test utility APIs and then if becoming
-    // permanent more easily promoted into regular static newFunction scenarios.
-    QScriptValue newLambdaFunction(std::function<QScriptValue(QScriptContext *context, QScriptEngine* engine)> operation, const QScriptValue& data = QScriptValue(), const QScriptEngine::ValueOwnership& ownership = QScriptEngine::AutoOwnership);
-
-#ifdef DEBUG_JS
-    static void _debugDump(const QString& header, const QScriptValue& object, const QString& footer = QString());
-#endif
-};
-
-// Standardized CPS callback helpers (see: http://fredkschott.com/post/2014/03/understanding-error-first-callbacks-in-node-js/)
-// These two helpers allow async JS APIs that use a callback parameter to be more friendly to scripters by accepting thisObject
-// context and adopting a consistent and intuitable callback signature:
-//   function callback(err, result) { if (err) { ... } else { /* do stuff with result */ } }
-//
-// To use, first pass the user-specified callback args in the same order used with optionally-scoped  Qt signal connections:
-//   auto handler = makeScopedHandlerObject(scopeOrCallback, optionalMethodOrName);
-// And then invoke the scoped handler later per CPS conventions:
-//   auto result = callScopedHandlerObject(handler, err, result);
-QScriptValue makeScopedHandlerObject(QScriptValue scopeOrCallback, QScriptValue methodOrName);
-QScriptValue callScopedHandlerObject(QScriptValue handler, QScriptValue err, QScriptValue result);
-
-// Lambda helps create callable QScriptValues out of std::functions:
-// (just meant for use from within the script engine itself)
-class Lambda : public QObject {
-    Q_OBJECT
-public:
-    Lambda(QScriptEngine *engine, std::function<QScriptValue(QScriptContext *context, QScriptEngine* engine)> operation, QScriptValue data);
-    ~Lambda();
-    public slots:
-        QScriptValue call();
-    QString toString() const;
-private:
-    QScriptEngine* engine;
-    std::function<QScriptValue(QScriptContext *context, QScriptEngine* engine)> operation;
-    QScriptValue data;
-};
-
-#endif // hifi_BaseScriptEngine_h
diff --git a/libraries/shared/src/EntityItemID.cpp b/libraries/shared/src/EntityItemID.cpp
new file mode 100644
index 00000000000..8cb34c13db8
--- /dev/null
+++ b/libraries/shared/src/EntityItemID.cpp
@@ -0,0 +1,42 @@
+//
+//  EntityItemID.cpp
+//  libraries/shared/src
+//
+//  Created by Brad Hefta-Gaub on 12/4/13.
+//  Copyright 2013 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "EntityItemID.h"
+#include <QtCore/QObject>
+#include <QDebug>
+
+#include "BufferParser.h"
+#include "UUID.h"
+
+int entityItemIDTypeID = qRegisterMetaType<EntityItemID>();
+
+EntityItemID::EntityItemID() : QUuid()
+{
+}
+
+
+EntityItemID::EntityItemID(const QUuid& id) : QUuid(id)
+{
+}
+
+// EntityItemID::EntityItemID(const EntityItemID& other) : QUuid(other)
+// {
+// }
+
+EntityItemID EntityItemID::readEntityItemIDFromBuffer(const unsigned char* data, int bytesLeftToRead) {
+    EntityItemID result;
+    if (bytesLeftToRead >= NUM_BYTES_RFC4122_UUID) {
+        BufferParser(data, bytesLeftToRead).readUuid(result);
+    }
+    return result;
+}
+
+size_t std::hash<EntityItemID>::operator()(const EntityItemID& id) const { return qHash(id); }
diff --git a/libraries/entities/src/EntityItemID.h b/libraries/shared/src/EntityItemID.h
similarity index 76%
rename from libraries/entities/src/EntityItemID.h
rename to libraries/shared/src/EntityItemID.h
index c9ffa13941c..51ea1871ae3 100644
--- a/libraries/entities/src/EntityItemID.h
+++ b/libraries/shared/src/EntityItemID.h
@@ -1,6 +1,6 @@
 //
 //  EntityItemID.h
-//  libraries/entities/src
+//  libraries/shared/src
 //
 //  Created by Brad Hefta-Gaub on 12/4/13.
 //  Copyright 2013 High Fidelity, Inc.
@@ -17,7 +17,7 @@
 #include <QDebug>
 #include <QObject>
 #include <QHash>
-#include <QScriptEngine>
+#include <QtCore/QSharedPointer>
 #include <QUuid>
 
 const QUuid UNKNOWN_ENTITY_ID; // null uuid
@@ -29,7 +29,6 @@ class EntityItemID : public QUuid {
     EntityItemID(const QUuid& id);
     // EntityItemID(const EntityItemID& other);
     static EntityItemID readEntityItemIDFromBuffer(const unsigned char* data, int bytesLeftToRead);
-    QScriptValue toScriptValue(QScriptEngine* engine) const;
 
     bool isInvalidID() const { return *this == UNKNOWN_ENTITY_ID; }
 };
@@ -41,9 +40,6 @@ inline QDebug operator<<(QDebug debug, const EntityItemID& id) {
 
 Q_DECLARE_METATYPE(EntityItemID);
 Q_DECLARE_METATYPE(QVector<EntityItemID>);
-QScriptValue EntityItemIDtoScriptValue(QScriptEngine* engine, const EntityItemID& properties);
-void EntityItemIDfromScriptValue(const QScriptValue &object, EntityItemID& properties);
-QVector<EntityItemID> qVectorEntityItemIDFromScriptValue(const QScriptValue& array);
 
 // Allow the use of std::unordered_map with QUuid keys
 namespace std { template<> struct hash<EntityItemID> { size_t operator()(const EntityItemID& id) const; }; }
diff --git a/libraries/shared/src/RegisteredMetaTypes.cpp b/libraries/shared/src/RegisteredMetaTypes.cpp
index c8b03694eba..d05d21afac3 100644
--- a/libraries/shared/src/RegisteredMetaTypes.cpp
+++ b/libraries/shared/src/RegisteredMetaTypes.cpp
@@ -22,8 +22,6 @@
 #include <QtGui/QVector3D>
 #include <QtGui/QQuaternion>
 #include <QtNetwork/QAbstractSocket>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptValueIterator>
 #include <QJsonDocument>
 
 int uint32MetaTypeId = qRegisterMetaType<glm::uint32>("uint32");
@@ -46,81 +44,6 @@ int voidLambdaType = qRegisterMetaType<std::function<void()>>();
 int variantLambdaType = qRegisterMetaType<std::function<QVariant()>>();
 int stencilModeMetaTypeId = qRegisterMetaType<StencilMaskMode>();
 
-void registerMetaTypes(QScriptEngine* engine) {
-    qScriptRegisterMetaType(engine, vec2ToScriptValue, vec2FromScriptValue);
-    qScriptRegisterMetaType(engine, vec3ToScriptValue, vec3FromScriptValue);
-    qScriptRegisterMetaType(engine, u8vec3ToScriptValue, u8vec3FromScriptValue);
-    qScriptRegisterMetaType(engine, vec4toScriptValue, vec4FromScriptValue);
-    qScriptRegisterMetaType(engine, quatToScriptValue, quatFromScriptValue);
-    qScriptRegisterMetaType(engine, mat4toScriptValue, mat4FromScriptValue);
-
-    qScriptRegisterMetaType(engine, qVectorVec3ToScriptValue, qVectorVec3FromScriptValue);
-    qScriptRegisterMetaType(engine, qVectorQuatToScriptValue, qVectorQuatFromScriptValue);
-    qScriptRegisterMetaType(engine, qVectorBoolToScriptValue, qVectorBoolFromScriptValue);
-    qScriptRegisterMetaType(engine, qVectorFloatToScriptValue, qVectorFloatFromScriptValue);
-    qScriptRegisterMetaType(engine, qVectorIntToScriptValue, qVectorIntFromScriptValue);
-    qScriptRegisterMetaType(engine, qVectorQUuidToScriptValue, qVectorQUuidFromScriptValue);
-
-    qScriptRegisterMetaType(engine, qSizeFToScriptValue, qSizeFFromScriptValue);
-    qScriptRegisterMetaType(engine, qRectToScriptValue, qRectFromScriptValue);
-    qScriptRegisterMetaType(engine, qURLToScriptValue, qURLFromScriptValue);
-    qScriptRegisterMetaType(engine, qColorToScriptValue, qColorFromScriptValue);
-
-    qScriptRegisterMetaType(engine, pickRayToScriptValue, pickRayFromScriptValue);
-    qScriptRegisterMetaType(engine, collisionToScriptValue, collisionFromScriptValue);
-    qScriptRegisterMetaType(engine, quuidToScriptValue, quuidFromScriptValue);
-    qScriptRegisterMetaType(engine, aaCubeToScriptValue, aaCubeFromScriptValue);
-
-    qScriptRegisterMetaType(engine, stencilMaskModeToScriptValue, stencilMaskModeFromScriptValue);
-
-    qScriptRegisterSequenceMetaType<QVector<unsigned int>>(engine);
-}
-
-QScriptValue vec2ToScriptValue(QScriptEngine* engine, const glm::vec2& vec2) {
-    auto prototype = engine->globalObject().property("__hifi_vec2__");
-    if (!prototype.property("defined").toBool()) {
-        prototype = engine->evaluate(
-            "__hifi_vec2__ = Object.defineProperties({}, { "
-            "defined: { value: true },"
-            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "u: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "v: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } }"
-            "})"
-        );
-    }
-    QScriptValue value = engine->newObject();
-    value.setProperty("x", vec2.x);
-    value.setProperty("y", vec2.y);
-    value.setPrototype(prototype);
-    return value;
-}
-
-void vec2FromScriptValue(const QScriptValue& object, glm::vec2& vec2) {
-    if (object.isNumber()) {
-        vec2 = glm::vec2(object.toVariant().toFloat());
-    } else if (object.isArray()) {
-        QVariantList list = object.toVariant().toList();
-        if (list.length() == 2) {
-            vec2.x = list[0].toFloat();
-            vec2.y = list[1].toFloat();
-        }
-    } else {
-        QScriptValue x = object.property("x");
-        if (!x.isValid()) {
-            x = object.property("u");
-        }
-
-        QScriptValue y = object.property("y");
-        if (!y.isValid()) {
-            y = object.property("v");
-        }
-
-        vec2.x = x.toVariant().toFloat();
-        vec2.y = y.toVariant().toFloat();
-    }
-}
-
 QVariant vec2ToVariant(const glm::vec2 &vec2) {
     if (vec2.x != vec2.x || vec2.y != vec2.y) {
         // if vec2 contains a NaN don't try to convert it
@@ -170,206 +93,6 @@ glm::vec2 vec2FromVariant(const QVariant &object) {
     return vec2FromVariant(object, valid);
 }
 
-QScriptValue vec3ToScriptValue(QScriptEngine* engine, const glm::vec3& vec3) {
-    auto prototype = engine->globalObject().property("__hifi_vec3__");
-    if (!prototype.property("defined").toBool()) {
-        prototype = engine->evaluate(
-            "__hifi_vec3__ = Object.defineProperties({}, { "
-            "defined: { value: true },"
-            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "2: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
-            "r: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "g: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "b: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
-            "red: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "green: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "blue: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } }"
-            "})"
-        );
-    }
-    QScriptValue value = engine->newObject();
-    value.setProperty("x", vec3.x);
-    value.setProperty("y", vec3.y);
-    value.setProperty("z", vec3.z);
-    value.setPrototype(prototype);
-    return value;
-}
-
-QScriptValue vec3ColorToScriptValue(QScriptEngine* engine, const glm::vec3& vec3) {
-    auto prototype = engine->globalObject().property("__hifi_vec3_color__");
-    if (!prototype.property("defined").toBool()) {
-        prototype = engine->evaluate(
-            "__hifi_vec3_color__ = Object.defineProperties({}, { "
-            "defined: { value: true },"
-            "0: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "1: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "2: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
-            "r: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "g: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "b: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
-            "x: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "y: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "z: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } }"
-            "})"
-        );
-    }
-    QScriptValue value = engine->newObject();
-    value.setProperty("red", vec3.x);
-    value.setProperty("green", vec3.y);
-    value.setProperty("blue", vec3.z);
-    value.setPrototype(prototype);
-    return value;
-}
-
-void vec3FromScriptValue(const QScriptValue& object, glm::vec3& vec3) {
-    if (object.isNumber()) {
-        vec3 = glm::vec3(object.toVariant().toFloat());
-    } else if (object.isString()) {
-        QColor qColor(object.toString());
-        if (qColor.isValid()) {
-            vec3.x = qColor.red();
-            vec3.y = qColor.green();
-            vec3.z = qColor.blue();
-        }
-    } else if (object.isArray()) {
-        QVariantList list = object.toVariant().toList();
-        if (list.length() == 3) {
-            vec3.x = list[0].toFloat();
-            vec3.y = list[1].toFloat();
-            vec3.z = list[2].toFloat();
-        }
-    } else {
-        QScriptValue x = object.property("x");
-        if (!x.isValid()) {
-            x = object.property("r");
-        }
-        if (!x.isValid()) {
-            x = object.property("red");
-        }
-
-        QScriptValue y = object.property("y");
-        if (!y.isValid()) {
-            y = object.property("g");
-        }
-        if (!y.isValid()) {
-            y = object.property("green");
-        }
-
-        QScriptValue z = object.property("z");
-        if (!z.isValid()) {
-            z = object.property("b");
-        }
-        if (!z.isValid()) {
-            z = object.property("blue");
-        }
-
-        vec3.x = x.toVariant().toFloat();
-        vec3.y = y.toVariant().toFloat();
-        vec3.z = z.toVariant().toFloat();
-    }
-}
-
-QScriptValue u8vec3ToScriptValue(QScriptEngine* engine, const glm::u8vec3& vec3) {
-    auto prototype = engine->globalObject().property("__hifi_u8vec3__");
-    if (!prototype.property("defined").toBool()) {
-        prototype = engine->evaluate(
-            "__hifi_u8vec3__ = Object.defineProperties({}, { "
-            "defined: { value: true },"
-            "0: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "1: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "2: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
-            "r: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "g: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "b: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } },"
-            "red: { set: function(nv) { return this.x = nv; }, get: function() { return this.x; } },"
-            "green: { set: function(nv) { return this.y = nv; }, get: function() { return this.y; } },"
-            "blue: { set: function(nv) { return this.z = nv; }, get: function() { return this.z; } }"
-            "})"
-        );
-    }
-    QScriptValue value = engine->newObject();
-    value.setProperty("x", vec3.x);
-    value.setProperty("y", vec3.y);
-    value.setProperty("z", vec3.z);
-    value.setPrototype(prototype);
-    return value;
-}
-
-QScriptValue u8vec3ColorToScriptValue(QScriptEngine* engine, const glm::u8vec3& vec3) {
-    auto prototype = engine->globalObject().property("__hifi_u8vec3_color__");
-    if (!prototype.property("defined").toBool()) {
-        prototype = engine->evaluate(
-            "__hifi_u8vec3_color__ = Object.defineProperties({}, { "
-            "defined: { value: true },"
-            "0: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "1: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "2: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
-            "r: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "g: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "b: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } },"
-            "x: { set: function(nv) { return this.red = nv; }, get: function() { return this.red; } },"
-            "y: { set: function(nv) { return this.green = nv; }, get: function() { return this.green; } },"
-            "z: { set: function(nv) { return this.blue = nv; }, get: function() { return this.blue; } }"
-            "})"
-        );
-    }
-    QScriptValue value = engine->newObject();
-    value.setProperty("red", vec3.x);
-    value.setProperty("green", vec3.y);
-    value.setProperty("blue", vec3.z);
-    value.setPrototype(prototype);
-    return value;
-}
-
-void u8vec3FromScriptValue(const QScriptValue& object, glm::u8vec3& vec3) {
-    if (object.isNumber()) {
-        vec3 = glm::vec3(object.toVariant().toUInt());
-    } else if (object.isString()) {
-        QColor qColor(object.toString());
-        if (qColor.isValid()) {
-            vec3.x = (uint8_t)qColor.red();
-            vec3.y = (uint8_t)qColor.green();
-            vec3.z = (uint8_t)qColor.blue();
-        }
-    } else if (object.isArray()) {
-        QVariantList list = object.toVariant().toList();
-        if (list.length() == 3) {
-            vec3.x = list[0].toUInt();
-            vec3.y = list[1].toUInt();
-            vec3.z = list[2].toUInt();
-        }
-    } else {
-        QScriptValue x = object.property("x");
-        if (!x.isValid()) {
-            x = object.property("r");
-        }
-        if (!x.isValid()) {
-            x = object.property("red");
-        }
-
-        QScriptValue y = object.property("y");
-        if (!y.isValid()) {
-            y = object.property("g");
-        }
-        if (!y.isValid()) {
-            y = object.property("green");
-        }
-
-        QScriptValue z = object.property("z");
-        if (!z.isValid()) {
-            z = object.property("b");
-        }
-        if (!z.isValid()) {
-            z = object.property("blue");
-        }
-
-        vec3.x = x.toVariant().toUInt();
-        vec3.y = y.toVariant().toUInt();
-        vec3.z = z.toVariant().toUInt();
-    }
-}
-
 QVariant vec3toVariant(const glm::vec3& vec3) {
     if (vec3.x != vec3.x || vec3.y != vec3.y || vec3.z != vec3.z) {
         // if vec3 contains a NaN don't try to convert it
@@ -540,22 +263,6 @@ glm::u8vec3 u8vec3FromVariant(const QVariant& object) {
     return u8vec3FromVariant(object, valid);
 }
 
-QScriptValue vec4toScriptValue(QScriptEngine* engine, const glm::vec4& vec4) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("x", vec4.x);
-    obj.setProperty("y", vec4.y);
-    obj.setProperty("z", vec4.z);
-    obj.setProperty("w", vec4.w);
-    return obj;
-}
-
-void vec4FromScriptValue(const QScriptValue& object, glm::vec4& vec4) {
-    vec4.x = object.property("x").toVariant().toFloat();
-    vec4.y = object.property("y").toVariant().toFloat();
-    vec4.z = object.property("z").toVariant().toFloat();
-    vec4.w = object.property("w").toVariant().toFloat();
-}
-
 QVariant vec4toVariant(const glm::vec4& vec4) {
     if (isNaN(vec4.x) || isNaN(vec4.y) || isNaN(vec4.z) || isNaN(vec4.w)) {
         // if vec4 contains a NaN don't try to convert it
@@ -606,46 +313,6 @@ glm::vec4 vec4FromVariant(const QVariant& object) {
     return vec4FromVariant(object, valid);
 }
 
-QScriptValue mat4toScriptValue(QScriptEngine* engine, const glm::mat4& mat4) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("r0c0", mat4[0][0]);
-    obj.setProperty("r1c0", mat4[0][1]);
-    obj.setProperty("r2c0", mat4[0][2]);
-    obj.setProperty("r3c0", mat4[0][3]);
-    obj.setProperty("r0c1", mat4[1][0]);
-    obj.setProperty("r1c1", mat4[1][1]);
-    obj.setProperty("r2c1", mat4[1][2]);
-    obj.setProperty("r3c1", mat4[1][3]);
-    obj.setProperty("r0c2", mat4[2][0]);
-    obj.setProperty("r1c2", mat4[2][1]);
-    obj.setProperty("r2c2", mat4[2][2]);
-    obj.setProperty("r3c2", mat4[2][3]);
-    obj.setProperty("r0c3", mat4[3][0]);
-    obj.setProperty("r1c3", mat4[3][1]);
-    obj.setProperty("r2c3", mat4[3][2]);
-    obj.setProperty("r3c3", mat4[3][3]);
-    return obj;
-}
-
-void mat4FromScriptValue(const QScriptValue& object, glm::mat4& mat4) {
-    mat4[0][0] = object.property("r0c0").toVariant().toFloat();
-    mat4[0][1] = object.property("r1c0").toVariant().toFloat();
-    mat4[0][2] = object.property("r2c0").toVariant().toFloat();
-    mat4[0][3] = object.property("r3c0").toVariant().toFloat();
-    mat4[1][0] = object.property("r0c1").toVariant().toFloat();
-    mat4[1][1] = object.property("r1c1").toVariant().toFloat();
-    mat4[1][2] = object.property("r2c1").toVariant().toFloat();
-    mat4[1][3] = object.property("r3c1").toVariant().toFloat();
-    mat4[2][0] = object.property("r0c2").toVariant().toFloat();
-    mat4[2][1] = object.property("r1c2").toVariant().toFloat();
-    mat4[2][2] = object.property("r2c2").toVariant().toFloat();
-    mat4[2][3] = object.property("r3c2").toVariant().toFloat();
-    mat4[3][0] = object.property("r0c3").toVariant().toFloat();
-    mat4[3][1] = object.property("r1c3").toVariant().toFloat();
-    mat4[3][2] = object.property("r2c3").toVariant().toFloat();
-    mat4[3][3] = object.property("r3c3").toVariant().toFloat();
-}
-
 QVariant mat4ToVariant(const glm::mat4& mat4) {
     if (mat4 != mat4) {
         // NaN
@@ -721,72 +388,6 @@ glm::mat4 mat4FromVariant(const QVariant& object) {
     return mat4FromVariant(object, valid);
 }
 
-QScriptValue qVectorVec3ColorToScriptValue(QScriptEngine* engine, const QVector<glm::vec3>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, vec3ColorToScriptValue(engine, vector.at(i)));
-    }
-    return array;
-}
-
-QScriptValue qVectorVec3ToScriptValue(QScriptEngine* engine, const QVector<glm::vec3>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, vec3ToScriptValue(engine, vector.at(i)));
-    }
-    return array;
-}
-
-QVector<glm::vec3> qVectorVec3FromScriptValue(const QScriptValue& array) {
-    QVector<glm::vec3> newVector;
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        glm::vec3 newVec3 = glm::vec3();
-        vec3FromScriptValue(array.property(i), newVec3);
-        newVector << newVec3;
-    }
-    return newVector;
-}
-
-void qVectorVec3FromScriptValue(const QScriptValue& array, QVector<glm::vec3>& vector) {
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        glm::vec3 newVec3 = glm::vec3();
-        vec3FromScriptValue(array.property(i), newVec3);
-        vector << newVec3;
-    }
-}
-
-QScriptValue quatToScriptValue(QScriptEngine* engine, const glm::quat& quat) {
-    QScriptValue obj = engine->newObject();
-    if (quat.x != quat.x || quat.y != quat.y || quat.z != quat.z || quat.w != quat.w) {
-        // if quat contains a NaN don't try to convert it
-        return obj;
-    }
-    obj.setProperty("x", quat.x);
-    obj.setProperty("y", quat.y);
-    obj.setProperty("z", quat.z);
-    obj.setProperty("w", quat.w);
-    return obj;
-}
-
-void quatFromScriptValue(const QScriptValue& object, glm::quat &quat) {
-    quat.x = object.property("x").toVariant().toFloat();
-    quat.y = object.property("y").toVariant().toFloat();
-    quat.z = object.property("z").toVariant().toFloat();
-    quat.w = object.property("w").toVariant().toFloat();
-
-    // enforce normalized quaternion
-    float length = glm::length(quat);
-    if (length > FLT_EPSILON) {
-        quat /= length;
-    } else {
-        quat = glm::quat();
-    }
-}
-
 glm::quat quatFromVariant(const QVariant &object, bool& isValid) {
     glm::quat q;
     if (object.canConvert<QQuaternion>()) {
@@ -844,159 +445,6 @@ QVariant quatToVariant(const glm::quat& quat) {
     return result;
 }
 
-QScriptValue qVectorQuatToScriptValue(QScriptEngine* engine, const QVector<glm::quat>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, quatToScriptValue(engine, vector.at(i)));
-    }
-    return array;
-}
-
-QScriptValue qVectorBoolToScriptValue(QScriptEngine* engine, const QVector<bool>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, vector.at(i));
-    }
-    return array;
-}
-
-QVector<float> qVectorFloatFromScriptValue(const QScriptValue& array) {
-    if(!array.isArray()) {
-        return QVector<float>();
-    }
-    QVector<float> newVector;
-    int length = array.property("length").toInteger();
-    newVector.reserve(length);
-    for (int i = 0; i < length; i++) {
-        if(array.property(i).isNumber()) {
-            newVector << array.property(i).toNumber();
-        }
-    }
-    
-    return newVector;
-}
-
-QScriptValue qVectorQUuidToScriptValue(QScriptEngine* engine, const QVector<QUuid>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, quuidToScriptValue(engine, vector.at(i)));
-    }
-    return array;
-}
-
-void qVectorQUuidFromScriptValue(const QScriptValue& array, QVector<QUuid>& vector) {
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        vector << array.property(i).toVariant().toUuid();
-    }
-}
-
-QVector<QUuid> qVectorQUuidFromScriptValue(const QScriptValue& array) {
-    if (!array.isArray()) {
-        return QVector<QUuid>(); 
-    }
-    QVector<QUuid> newVector;
-    int length = array.property("length").toInteger();
-    newVector.reserve(length);
-    for (int i = 0; i < length; i++) {
-        QString uuidAsString = array.property(i).toString();
-        QUuid fromString(uuidAsString);
-        newVector << fromString;
-    }
-    return newVector;
-}
-
-QScriptValue qVectorFloatToScriptValue(QScriptEngine* engine, const QVector<float>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        float num = vector.at(i);
-        array.setProperty(i, QScriptValue(num));
-    }
-    return array;
-}
-
-QScriptValue qVectorIntToScriptValue(QScriptEngine* engine, const QVector<uint32_t>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        int num = vector.at(i);
-        array.setProperty(i, QScriptValue(num));
-    }
-    return array;
-}
-
-void qVectorFloatFromScriptValue(const QScriptValue& array, QVector<float>& vector) {
-    int length = array.property("length").toInteger();
-    
-    for (int i = 0; i < length; i++) {
-        vector << array.property(i).toVariant().toFloat();
-    }
-}
-
-void qVectorIntFromScriptValue(const QScriptValue& array, QVector<uint32_t>& vector) {
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        vector << array.property(i).toVariant().toInt();
-    }
-}
-
-QVector<glm::quat> qVectorQuatFromScriptValue(const QScriptValue& array){
-    QVector<glm::quat> newVector;
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        glm::quat newQuat = glm::quat();
-        quatFromScriptValue(array.property(i), newQuat);
-        newVector << newQuat;
-    }
-    return newVector;
-}
-
-void qVectorQuatFromScriptValue(const QScriptValue& array, QVector<glm::quat>& vector ) {
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        glm::quat newQuat = glm::quat();
-        quatFromScriptValue(array.property(i), newQuat);
-        vector << newQuat;
-    }
-}
-
-QVector<bool> qVectorBoolFromScriptValue(const QScriptValue& array){
-    QVector<bool> newVector;
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        newVector << array.property(i).toBool();
-    }
-    return newVector;
-}
-
-void qVectorBoolFromScriptValue(const QScriptValue& array, QVector<bool>& vector ) {
-    int length = array.property("length").toInteger();
-
-    for (int i = 0; i < length; i++) {
-        vector << array.property(i).toBool();
-    }
-}
-
-QScriptValue qRectToScriptValue(QScriptEngine* engine, const QRect& rect) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("x", rect.x());
-    obj.setProperty("y", rect.y());
-    obj.setProperty("width", rect.width());
-    obj.setProperty("height", rect.height());
-    return obj;
-}
-
-void qRectFromScriptValue(const QScriptValue &object, QRect& rect) {
-    rect.setX(object.property("x").toVariant().toInt());
-    rect.setY(object.property("y").toVariant().toInt());
-    rect.setWidth(object.property("width").toVariant().toInt());
-    rect.setHeight(object.property("height").toVariant().toInt());
-}
-
 QVariant qRectToVariant(const QRect& rect) {
     QVariantMap obj;
     obj["x"] = rect.x();
@@ -1028,22 +476,6 @@ QRect qRectFromVariant(const QVariant& object) {
     return qRectFromVariant(object, valid);
 }
 
-QScriptValue qRectFToScriptValue(QScriptEngine* engine, const QRectF& rect) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("x", rect.x());
-    obj.setProperty("y", rect.y());
-    obj.setProperty("width", rect.width());
-    obj.setProperty("height", rect.height());
-    return obj;
-}
-
-void qRectFFromScriptValue(const QScriptValue &object, QRectF& rect) {
-    rect.setX(object.property("x").toVariant().toFloat());
-    rect.setY(object.property("y").toVariant().toFloat());
-    rect.setWidth(object.property("width").toVariant().toFloat());
-    rect.setHeight(object.property("height").toVariant().toFloat());
-}
-
 QVariant qRectFToVariant(const QRectF& rect) {
     QVariantMap obj;
     obj["x"] = rect.x();
@@ -1075,100 +507,6 @@ QRectF qRectFFromVariant(const QVariant& object) {
     return qRectFFromVariant(object, valid);
 }
 
-QScriptValue qColorToScriptValue(QScriptEngine* engine, const QColor& color) {
-    QScriptValue object = engine->newObject();
-    object.setProperty("red", color.red());
-    object.setProperty("green", color.green());
-    object.setProperty("blue", color.blue());
-    object.setProperty("alpha", color.alpha());
-    return object;
-}
-
-/*@jsdoc
- * An axis-aligned cube, defined as the bottom right near (minimum axes values) corner of the cube plus the dimension of its 
- * sides.
- * @typedef {object} AACube
- * @property {number} x - X coordinate of the brn corner of the cube.
- * @property {number} y - Y coordinate of the brn corner of the cube.
- * @property {number} z - Z coordinate of the brn corner of the cube.
- * @property {number} scale - The dimensions of each side of the cube.
- */
-QScriptValue aaCubeToScriptValue(QScriptEngine* engine, const AACube& aaCube) {
-    QScriptValue obj = engine->newObject();
-    const glm::vec3& corner = aaCube.getCorner();
-    obj.setProperty("x", corner.x);
-    obj.setProperty("y", corner.y);
-    obj.setProperty("z", corner.z);
-    obj.setProperty("scale", aaCube.getScale());
-    return obj;
-}
-
-void aaCubeFromScriptValue(const QScriptValue &object, AACube& aaCube) {
-    glm::vec3 corner;
-    corner.x = object.property("x").toVariant().toFloat();
-    corner.y = object.property("y").toVariant().toFloat();
-    corner.z = object.property("z").toVariant().toFloat();
-    float scale = object.property("scale").toVariant().toFloat();
-
-    aaCube.setBox(corner, scale);
-}
-
-void qColorFromScriptValue(const QScriptValue& object, QColor& color) {
-    if (object.isNumber()) {
-        color.setRgb(object.toUInt32());
-    
-    } else if (object.isString()) {
-        color.setNamedColor(object.toString());
-            
-    } else {
-        QScriptValue alphaValue = object.property("alpha");
-        color.setRgb(object.property("red").toInt32(), object.property("green").toInt32(), object.property("blue").toInt32(),
-            alphaValue.isNumber() ? alphaValue.toInt32() : 255);
-    }
-}
-
-QScriptValue qURLToScriptValue(QScriptEngine* engine, const QUrl& url) {
-    return url.toString();
-}
-
-void qURLFromScriptValue(const QScriptValue& object, QUrl& url) {
-    url = object.toString();
-}
-
-QScriptValue pickRayToScriptValue(QScriptEngine* engine, const PickRay& pickRay) {
-    QScriptValue obj = engine->newObject();
-    QScriptValue origin = vec3ToScriptValue(engine, pickRay.origin);
-    obj.setProperty("origin", origin);
-    QScriptValue direction = vec3ToScriptValue(engine, pickRay.direction);
-    obj.setProperty("direction", direction);
-    return obj;
-}
-
-void pickRayFromScriptValue(const QScriptValue& object, PickRay& pickRay) {
-    QScriptValue originValue = object.property("origin");
-    if (originValue.isValid()) {
-        auto x = originValue.property("x");
-        auto y = originValue.property("y");
-        auto z = originValue.property("z");
-        if (x.isValid() && y.isValid() && z.isValid()) {
-            pickRay.origin.x = x.toVariant().toFloat();
-            pickRay.origin.y = y.toVariant().toFloat();
-            pickRay.origin.z = z.toVariant().toFloat();
-        }
-    }
-    QScriptValue directionValue = object.property("direction");
-    if (directionValue.isValid()) {
-        auto x = directionValue.property("x");
-        auto y = directionValue.property("y");
-        auto z = directionValue.property("z");
-        if (x.isValid() && y.isValid() && z.isValid()) {
-            pickRay.direction.x = x.toVariant().toFloat();
-            pickRay.direction.y = y.toVariant().toFloat();
-            pickRay.direction.z = z.toVariant().toFloat();
-        }
-    }
-}
-
 /*@jsdoc
  * Details of a collision between avatars and entities.
  * @typedef {object} Collision
@@ -1179,63 +517,12 @@ void pickRayFromScriptValue(const QScriptValue& object, PickRay& pickRay) {
  * @property {Vec3} contactPoint - The point of contact.
  * @property {Vec3} velocityChange - The change in relative velocity of the two items, in m/s.
  */
-QScriptValue collisionToScriptValue(QScriptEngine* engine, const Collision& collision) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("type", collision.type);
-    obj.setProperty("idA", quuidToScriptValue(engine, collision.idA));
-    obj.setProperty("idB", quuidToScriptValue(engine, collision.idB));
-    obj.setProperty("penetration", vec3ToScriptValue(engine, collision.penetration));
-    obj.setProperty("contactPoint", vec3ToScriptValue(engine, collision.contactPoint));
-    obj.setProperty("velocityChange", vec3ToScriptValue(engine, collision.velocityChange));
-    return obj;
-}
-
-void collisionFromScriptValue(const QScriptValue &object, Collision& collision) {
-    // TODO: implement this when we know what it means to accept collision events from JS
-}
-
 void Collision::invert() {
     std::swap(idA, idB);
     contactPoint += penetration;
     penetration *= -1.0f;
 }
 
-QScriptValue quuidToScriptValue(QScriptEngine* engine, const QUuid& uuid) {
-    if (uuid.isNull()) {
-        return QScriptValue::NullValue;
-    }
-    QScriptValue obj(uuid.toString());
-    return obj;
-}
-
-void quuidFromScriptValue(const QScriptValue& object, QUuid& uuid) {
-    if (object.isNull()) {
-        uuid = QUuid();
-        return;
-    }
-    QString uuidAsString = object.toVariant().toString();
-    QUuid fromString(uuidAsString);
-    uuid = fromString;
-}
-
-/*@jsdoc
- * A 2D size value.
- * @typedef {object} Size
- * @property {number} height - The height value.
- * @property {number} width - The width value.
- */
-QScriptValue qSizeFToScriptValue(QScriptEngine* engine, const QSizeF& qSizeF) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("width", qSizeF.width());
-    obj.setProperty("height", qSizeF.height());
-    return obj;
-}
-
-void qSizeFFromScriptValue(const QScriptValue& object, QSizeF& qSizeF) {
-    qSizeF.setWidth(object.property("width").toVariant().toFloat());
-    qSizeF.setHeight(object.property("height").toVariant().toFloat());
-}
-
 AnimationDetails::AnimationDetails() :
     role(), url(), fps(0.0f), priority(0.0f), loop(false), hold(false),
     startAutomatically(false), firstFrame(0.0f), lastFrame(0.0f), running(false), currentFrame(0.0f) {
@@ -1248,116 +535,6 @@ AnimationDetails::AnimationDetails(QString role, QUrl url, float fps, float prio
     running(running), currentFrame(currentFrame), allowTranslation(allowTranslation) {
 }
 
-/*@jsdoc
- * The details of an animation that is playing.
- * @typedef {object} Avatar.AnimationDetails
- * @property {string} role - <em>Not used.</em>
- * @property {string} url - The URL to the animation file. Animation files need to be in glTF or FBX format but only need to 
- *     contain the avatar skeleton and animation data. glTF models may be in JSON or binary format (".gltf" or ".glb" URLs 
- *     respectively).
- *     <p><strong>Warning:</strong> glTF animations currently do not always animate correctly.</p>
- * @property {number} fps - The frames per second(FPS) rate for the animation playback. 30 FPS is normal speed.
- * @property {number} priority - <em>Not used.</em>
- * @property {boolean} loop - <code>true</code> if the animation should loop, <code>false</code> if it shouldn't.
- * @property {boolean} hold - <em>Not used.</em>
- * @property {number} firstFrame - The frame the animation should start at.
- * @property {number} lastFrame - The frame the animation should stop at.
- * @property {boolean} running - <em>Not used.</em>
- * @property {number} currentFrame - The current frame being played.
- * @property {boolean} startAutomatically - <em>Not used.</em>
- * @property {boolean} allowTranslation - <em>Not used.</em>
- */
-QScriptValue animationDetailsToScriptValue(QScriptEngine* engine, const AnimationDetails& details) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("role", details.role);
-    obj.setProperty("url", details.url.toString());
-    obj.setProperty("fps", details.fps);
-    obj.setProperty("priority", details.priority);
-    obj.setProperty("loop", details.loop);
-    obj.setProperty("hold", details.hold);
-    obj.setProperty("startAutomatically", details.startAutomatically);
-    obj.setProperty("firstFrame", details.firstFrame);
-    obj.setProperty("lastFrame", details.lastFrame);
-    obj.setProperty("running", details.running);
-    obj.setProperty("currentFrame", details.currentFrame);
-    obj.setProperty("allowTranslation", details.allowTranslation);
-    return obj;
-}
-
-void animationDetailsFromScriptValue(const QScriptValue& object, AnimationDetails& details) {
-    // nothing for now...
-}
-
-QScriptValue meshToScriptValue(QScriptEngine* engine, MeshProxy* const &in) {
-    return engine->newQObject(in, QScriptEngine::QtOwnership,
-        QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects);
-}
-
-void meshFromScriptValue(const QScriptValue& value, MeshProxy* &out) {
-    out = qobject_cast<MeshProxy*>(value.toQObject());
-}
-
-QScriptValue meshesToScriptValue(QScriptEngine* engine, const MeshProxyList &in) {
-    // QScriptValueList result;
-    QScriptValue result = engine->newArray();
-    int i = 0;
-    foreach(MeshProxy* const meshProxy, in) {
-        result.setProperty(i++, meshToScriptValue(engine, meshProxy));
-    }
-    return result;
-}
-
-void meshesFromScriptValue(const QScriptValue& value, MeshProxyList &out) {
-    QScriptValueIterator itr(value);
-
-    qDebug() << "in meshesFromScriptValue, value.length =" << value.property("length").toInt32();
-
-    while (itr.hasNext()) {
-        itr.next();
-        MeshProxy* meshProxy = qscriptvalue_cast<MeshProxyList::value_type>(itr.value());
-        if (meshProxy) {
-            out.append(meshProxy);
-        } else {
-            qDebug() << "null meshProxy";
-        }
-    }
-}
-
-
-/*@jsdoc
- * A triangle in a mesh.
- * @typedef {object} MeshFace
- * @property {number[]} vertices - The indexes of the three vertices that make up the face.
- */
-QScriptValue meshFaceToScriptValue(QScriptEngine* engine, const MeshFace &meshFace) {
-    QScriptValue obj = engine->newObject();
-    obj.setProperty("vertices", qVectorIntToScriptValue(engine, meshFace.vertexIndices));
-    return obj;
-}
-
-void meshFaceFromScriptValue(const QScriptValue &object, MeshFace& meshFaceResult) {
-    qVectorIntFromScriptValue(object.property("vertices"), meshFaceResult.vertexIndices);
-}
-
-QScriptValue qVectorMeshFaceToScriptValue(QScriptEngine* engine, const QVector<MeshFace>& vector) {
-    QScriptValue array = engine->newArray();
-    for (int i = 0; i < vector.size(); i++) {
-        array.setProperty(i, meshFaceToScriptValue(engine, vector.at(i)));
-    }
-    return array;
-}
-
-void qVectorMeshFaceFromScriptValue(const QScriptValue& array, QVector<MeshFace>& result) {
-    int length = array.property("length").toInteger();
-    result.clear();
-
-    for (int i = 0; i < length; i++) {
-        MeshFace meshFace = MeshFace();
-        meshFaceFromScriptValue(array.property(i), meshFace);
-        result << meshFace;
-    }
-}
-
 QVariantMap parseTexturesToMap(QString newTextures, const QVariantMap& defaultTextures) {
     // If textures are unset, revert to original textures
     if (newTextures.isEmpty()) {
@@ -1392,11 +569,3 @@ QVariantMap parseTexturesToMap(QString newTextures, const QVariantMap& defaultTe
 
     return toReturn;
 }
-
-QScriptValue stencilMaskModeToScriptValue(QScriptEngine* engine, const StencilMaskMode& stencilMode) {
-    return engine->newVariant((int)stencilMode);
-}
-
-void stencilMaskModeFromScriptValue(const QScriptValue& object, StencilMaskMode& stencilMode) {
-    stencilMode = StencilMaskMode(object.toVariant().toInt());
-}
\ No newline at end of file
diff --git a/libraries/shared/src/RegisteredMetaTypes.h b/libraries/shared/src/RegisteredMetaTypes.h
index 39245b5a491..e09d2e248ff 100644
--- a/libraries/shared/src/RegisteredMetaTypes.h
+++ b/libraries/shared/src/RegisteredMetaTypes.h
@@ -12,7 +12,6 @@
 #ifndef hifi_RegisteredMetaTypes_h
 #define hifi_RegisteredMetaTypes_h
 
-#include <QtScript/QScriptEngine>
 #include <QtCore/QUuid>
 #include <QtCore/QUrl>
 
@@ -43,8 +42,6 @@ Q_DECLARE_METATYPE(AACube)
 Q_DECLARE_METATYPE(std::function<void()>);
 Q_DECLARE_METATYPE(std::function<QVariant()>);
 
-void registerMetaTypes(QScriptEngine* engine);
-
 // Mat4
 /*@jsdoc
  * A 4 x 4 matrix, typically containing a scale, rotation, and translation transform. See also the {@link Mat4(0)|Mat4} object.
@@ -67,9 +64,6 @@ void registerMetaTypes(QScriptEngine* engine);
  * @property {number} r2c3 - Row 2, column 3 value.
  * @property {number} r3c3 - Row 3, column 3 value.
  */
-QScriptValue mat4toScriptValue(QScriptEngine* engine, const glm::mat4& mat4);
-void mat4FromScriptValue(const QScriptValue& object, glm::mat4& mat4);
-
 QVariant mat4ToVariant(const glm::mat4& mat4);
 glm::mat4 mat4FromVariant(const QVariant& object, bool& valid);
 glm::mat4 mat4FromVariant(const QVariant& object);
@@ -88,9 +82,6 @@ glm::mat4 mat4FromVariant(const QVariant& object);
 * var color = Entities.getEntityProperties(<id>).materialMappingPos;             // { x: 0.7, y: 0.7 }
 * color.v = 0.8;                                                                 // { x: 0.7, y: 0.8 }
 */
-QScriptValue vec2ToScriptValue(QScriptEngine* engine, const glm::vec2& vec2);
-void vec2FromScriptValue(const QScriptValue& object, glm::vec2& vec2);
-
 QVariant vec2ToVariant(const glm::vec2& vec2);
 glm::vec2 vec2FromVariant(const QVariant& object, bool& valid);
 glm::vec2 vec2FromVariant(const QVariant& object);
@@ -115,10 +106,6 @@ glm::vec2 vec2FromVariant(const QVariant& object);
 * Entities.editEntity(<id>, { position: "red"});                                // { x: 255, y: 0, z: 0 }
 * Entities.editEntity(<id>, { position: "#00FF00"});                            // { x: 0, y: 255, z: 0 }
 */
-QScriptValue vec3ToScriptValue(QScriptEngine* engine, const glm::vec3& vec3);
-QScriptValue vec3ColorToScriptValue(QScriptEngine* engine, const glm::vec3& vec3);
-void vec3FromScriptValue(const QScriptValue& object, glm::vec3& vec3);
-
 QVariant vec3toVariant(const glm::vec3& vec3);
 glm::vec3 vec3FromVariant(const QVariant &object, bool& valid);
 glm::vec3 vec3FromVariant(const QVariant &object);
@@ -161,10 +148,6 @@ glm::vec3 vec3FromVariant(const QVariant &object);
  * Entities.editEntity(<id>, { color: "red"});                                // { red: 255, green: 0, blue: 0 }
  * Entities.editEntity(<id>, { color: "#00FF00"});                            // { red: 0, green: 255, blue: 0 }
  */
-QScriptValue u8vec3ToScriptValue(QScriptEngine* engine, const glm::u8vec3& vec3);
-QScriptValue u8vec3ColorToScriptValue(QScriptEngine* engine, const glm::u8vec3& vec3);
-void u8vec3FromScriptValue(const QScriptValue& object, glm::u8vec3& vec3);
-
 QVariant u8vec3toVariant(const glm::u8vec3& vec3);
 QVariant u8vec3ColortoVariant(const glm::u8vec3& vec3);
 glm::u8vec3 u8vec3FromVariant(const QVariant &object, bool& valid);
@@ -179,16 +162,11 @@ glm::u8vec3 u8vec3FromVariant(const QVariant &object);
  * @property {number} z - Z-coordinate of the vector.
  * @property {number} w - W-coordinate of the vector.
  */
-QScriptValue vec4toScriptValue(QScriptEngine* engine, const glm::vec4& vec4);
-void vec4FromScriptValue(const QScriptValue& object, glm::vec4& vec4);
 QVariant vec4toVariant(const glm::vec4& vec4);
 glm::vec4 vec4FromVariant(const QVariant &object, bool& valid);
 glm::vec4 vec4FromVariant(const QVariant &object);
 
 // Quaternions
-QScriptValue quatToScriptValue(QScriptEngine* engine, const glm::quat& quat);
-void quatFromScriptValue(const QScriptValue &object, glm::quat& quat);
-
 QVariant quatToVariant(const glm::quat& quat);
 glm::quat quatFromVariant(const QVariant &object, bool& isValid);
 glm::quat quatFromVariant(const QVariant &object);
@@ -201,59 +179,14 @@ glm::quat quatFromVariant(const QVariant &object);
  * @property {number} width - Width of the rectangle.
  * @property {number} height - Height of the rectangle.
  */
-QScriptValue qRectToScriptValue(QScriptEngine* engine, const QRect& rect);
-void qRectFromScriptValue(const QScriptValue& object, QRect& rect);
 QRect qRectFromVariant(const QVariant& object, bool& isValid);
 QRect qRectFromVariant(const QVariant& object);
 QVariant qRectToVariant(const QRect& rect);
 
-QScriptValue qRectFToScriptValue(QScriptEngine* engine, const QRectF& rect);
-void qRectFFromScriptValue(const QScriptValue& object, QRectF& rect);
 QRectF qRectFFromVariant(const QVariant& object, bool& isValid);
 QRectF qRectFFromVariant(const QVariant& object);
 QVariant qRectFToVariant(const QRectF& rect);
 
-// QColor
-QScriptValue qColorToScriptValue(QScriptEngine* engine, const QColor& color);
-void qColorFromScriptValue(const QScriptValue& object, QColor& color);
-
-QScriptValue qURLToScriptValue(QScriptEngine* engine, const QUrl& url);
-void qURLFromScriptValue(const QScriptValue& object, QUrl& url);
-
-// vector<vec3>
-Q_DECLARE_METATYPE(QVector<glm::vec3>)
-QScriptValue qVectorVec3ToScriptValue(QScriptEngine* engine, const QVector<glm::vec3>& vector);
-QScriptValue qVectorVec3ColorToScriptValue(QScriptEngine* engine, const QVector<glm::vec3>& vector);
-void qVectorVec3FromScriptValue(const QScriptValue& array, QVector<glm::vec3>& vector);
-QVector<glm::vec3> qVectorVec3FromScriptValue(const QScriptValue& array);
-
-// vector<quat>
-Q_DECLARE_METATYPE(QVector<glm::quat>)
-QScriptValue qVectorQuatToScriptValue(QScriptEngine* engine, const QVector<glm::quat>& vector);
-void qVectorQuatFromScriptValue(const QScriptValue& array, QVector<glm::quat>& vector);
-QVector<glm::quat> qVectorQuatFromScriptValue(const QScriptValue& array);
-
-// vector<bool>
-QScriptValue qVectorBoolToScriptValue(QScriptEngine* engine, const QVector<bool>& vector);
-void qVectorBoolFromScriptValue(const QScriptValue& array, QVector<bool>& vector);
-QVector<bool> qVectorBoolFromScriptValue(const QScriptValue& array);
-
-// vector<float>
-QScriptValue qVectorFloatToScriptValue(QScriptEngine* engine, const QVector<float>& vector);
-void qVectorFloatFromScriptValue(const QScriptValue& array, QVector<float>& vector);
-QVector<float> qVectorFloatFromScriptValue(const QScriptValue& array);
-
-// vector<uint32_t>
-QScriptValue qVectorIntToScriptValue(QScriptEngine* engine, const QVector<uint32_t>& vector);
-void qVectorIntFromScriptValue(const QScriptValue& array, QVector<uint32_t>& vector);
-
-QScriptValue qVectorQUuidToScriptValue(QScriptEngine* engine, const QVector<QUuid>& vector);
-void qVectorQUuidFromScriptValue(const QScriptValue& array, QVector<QUuid>& vector);
-QVector<QUuid> qVectorQUuidFromScriptValue(const QScriptValue& array);
-
-QScriptValue aaCubeToScriptValue(QScriptEngine* engine, const AACube& aaCube);
-void aaCubeFromScriptValue(const QScriptValue &object, AACube& aaCube);
-
 // MathPicks also have to overide operator== for their type
 class MathPick {
 public:
@@ -292,8 +225,6 @@ class PickRay : public MathPick {
     }
 };
 Q_DECLARE_METATYPE(PickRay)
-QScriptValue pickRayToScriptValue(QScriptEngine* engine, const PickRay& pickRay);
-void pickRayFromScriptValue(const QScriptValue& object, PickRay& pickRay);
 
 /*@jsdoc
  * The tip of a stylus.
@@ -644,22 +575,6 @@ class Collision {
     glm::vec3 velocityChange;
 };
 Q_DECLARE_METATYPE(Collision)
-QScriptValue collisionToScriptValue(QScriptEngine* engine, const Collision& collision);
-void collisionFromScriptValue(const QScriptValue &object, Collision& collision);
-
-/*@jsdoc
- * UUIDs (Universally Unique IDentifiers) are used to uniquely identify entities, avatars, and the like. They are represented 
- * in JavaScript as strings in the format, <code>"{nnnnnnnn-nnnn-nnnn-nnnn-nnnnnnnnnnnn}"</code>, where the "n"s are
- * hexadecimal digits.
- * @typedef {string} Uuid
- */
-//Q_DECLARE_METATYPE(QUuid) // don't need to do this for QUuid since it's already a meta type
-QScriptValue quuidToScriptValue(QScriptEngine* engine, const QUuid& uuid);
-void quuidFromScriptValue(const QScriptValue& object, QUuid& uuid);
-
-//Q_DECLARE_METATYPE(QSizeF) // Don't need to to this becase it's arleady a meta type
-QScriptValue qSizeFToScriptValue(QScriptEngine* engine, const QSizeF& qSizeF);
-void qSizeFFromScriptValue(const QScriptValue& object, QSizeF& qSizeF);
 
 class AnimationDetails {
 public:
@@ -681,8 +596,6 @@ class AnimationDetails {
     bool allowTranslation;
 };
 Q_DECLARE_METATYPE(AnimationDetails);
-QScriptValue animationDetailsToScriptValue(QScriptEngine* engine, const AnimationDetails& event);
-void animationDetailsFromScriptValue(const QScriptValue& object, AnimationDetails& event);
 
 namespace graphics {
     class Mesh;
@@ -733,12 +646,6 @@ class MeshProxyList : public QList<MeshProxy*> {}; // typedef and using fight wi
 Q_DECLARE_METATYPE(MeshProxyList);
 
 
-QScriptValue meshToScriptValue(QScriptEngine* engine, MeshProxy* const &in);
-void meshFromScriptValue(const QScriptValue& value, MeshProxy* &out);
-
-QScriptValue meshesToScriptValue(QScriptEngine* engine, const MeshProxyList &in);
-void meshesFromScriptValue(const QScriptValue& value, MeshProxyList &out);
-
 class MeshFace {
 
 public:
@@ -752,15 +659,8 @@ class MeshFace {
 Q_DECLARE_METATYPE(MeshFace)
 Q_DECLARE_METATYPE(QVector<MeshFace>)
 
-QScriptValue meshFaceToScriptValue(QScriptEngine* engine, const MeshFace &meshFace);
-void meshFaceFromScriptValue(const QScriptValue &object, MeshFace& meshFaceResult);
-QScriptValue qVectorMeshFaceToScriptValue(QScriptEngine* engine, const QVector<MeshFace>& vector);
-void qVectorMeshFaceFromScriptValue(const QScriptValue& array, QVector<MeshFace>& result);
-
 QVariantMap parseTexturesToMap(QString textures, const QVariantMap& defaultTextures);
 
 Q_DECLARE_METATYPE(StencilMaskMode)
-QScriptValue stencilMaskModeToScriptValue(QScriptEngine* engine, const StencilMaskMode& stencilMode);
-void stencilMaskModeFromScriptValue(const QScriptValue& object, StencilMaskMode& stencilMode);
 
 #endif // hifi_RegisteredMetaTypes_h
diff --git a/libraries/shared/src/ScriptValueUtils.cpp b/libraries/shared/src/ScriptValueUtils.cpp
deleted file mode 100644
index e352c0546d9..00000000000
--- a/libraries/shared/src/ScriptValueUtils.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-//
-//  ScriptValueUtils.cpp
-//  libraries/shared/src
-//
-//  Created by Anthony Thibault on 4/15/16.
-//  Copyright 2016 High Fidelity, Inc.
-//
-//  Utilities for working with QtScriptValues
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#include "ScriptValueUtils.h"
-
-bool isListOfStrings(const QScriptValue& arg) {
-    if (!arg.isArray()) {
-        return false;
-    }
-
-    auto lengthProperty = arg.property("length");
-    if (!lengthProperty.isNumber()) {
-        return false;
-    }
-
-    int length = lengthProperty.toInt32();
-    for (int i = 0; i < length; i++) {
-        if (!arg.property(i).isString()) {
-            return false;
-        }
-    }
-
-    return true;
-}
diff --git a/libraries/shared/src/ScriptValueUtils.h b/libraries/shared/src/ScriptValueUtils.h
deleted file mode 100644
index 2e120a7217a..00000000000
--- a/libraries/shared/src/ScriptValueUtils.h
+++ /dev/null
@@ -1,21 +0,0 @@
-//
-//  ScriptValueUtils.h
-//  libraries/shared/src
-//
-//  Created by Anthony Thibault on 4/15/16.
-//  Copyright 2016 High Fidelity, Inc.
-//
-//  Utilities for working with QtScriptValues
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#ifndef hifi_ScriptValueUtils_h
-#define hifi_ScriptValueUtils_h
-
-#include <QScriptValue>
-
-bool isListOfStrings(const QScriptValue& value);
-
-#endif // #define hifi_ScriptValueUtils_h
diff --git a/libraries/shared/src/VariantMapToScriptValue.h b/libraries/shared/src/VariantMapToScriptValue.h
deleted file mode 100644
index ea65cccb3d4..00000000000
--- a/libraries/shared/src/VariantMapToScriptValue.h
+++ /dev/null
@@ -1,18 +0,0 @@
-//
-//  VariantMapToScriptValue.h
-//  libraries/shared/src/
-//
-//  Created by Brad Hefta-Gaub on 12/6/13.
-//  Copyright 2013 High Fidelity, Inc.
-//
-//  Distributed under the Apache License, Version 2.0.
-//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
-//
-
-#include <QVariant>
-#include <QScriptValue>
-#include <QScriptEngine>
-
-QScriptValue variantToScriptValue(QVariant& qValue, QScriptEngine& scriptEngine);
-QScriptValue variantMapToScriptValue(QVariantMap& variantMap, QScriptEngine& scriptEngine);
-QScriptValue variantListToScriptValue(QVariantList& variantList, QScriptEngine& scriptEngine);
diff --git a/libraries/shared/src/shared/MiniPromises.cpp b/libraries/shared/src/shared/MiniPromises.cpp
index 21a3f44d50f..57b4496b96f 100644
--- a/libraries/shared/src/shared/MiniPromises.cpp
+++ b/libraries/shared/src/shared/MiniPromises.cpp
@@ -7,20 +7,5 @@
 //
 
 #include "MiniPromises.h"
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValue>
 
 int MiniPromise::metaTypeID = qRegisterMetaType<MiniPromise::Promise>("MiniPromise::Promise");
-
-namespace {
-    void promiseFromScriptValue(const QScriptValue& object, MiniPromise::Promise& promise) {
-        Q_ASSERT(false);
-    }
-    QScriptValue promiseToScriptValue(QScriptEngine *engine, const MiniPromise::Promise& promise) {
-        return engine->newQObject(promise.get());
-    }
-}
-void MiniPromise::registerMetaTypes(QObject* engine) {
-    auto scriptEngine = qobject_cast<QScriptEngine*>(engine);
-    qScriptRegisterMetaType(scriptEngine, promiseToScriptValue, promiseFromScriptValue);
-}
diff --git a/libraries/shared/src/shared/MiniPromises.h b/libraries/shared/src/shared/MiniPromises.h
index 30b57ad7b84..e49bc48d18e 100644
--- a/libraries/shared/src/shared/MiniPromises.h
+++ b/libraries/shared/src/shared/MiniPromises.h
@@ -42,7 +42,6 @@ class MiniPromise : public QObject, public std::enable_shared_from_this<MiniProm
     using HandlerFunctions = QVector<HandlerFunction>;
     using Promise = std::shared_ptr<MiniPromise>;
 
-    static void registerMetaTypes(QObject* engine);
     static int metaTypeID;
 
     MiniPromise() {}
diff --git a/libraries/shared/src/shared/QtHelpers.cpp b/libraries/shared/src/shared/QtHelpers.cpp
index ed387a97634..477176ecb9a 100644
--- a/libraries/shared/src/shared/QtHelpers.cpp
+++ b/libraries/shared/src/shared/QtHelpers.cpp
@@ -40,6 +40,16 @@ void addBlockingForbiddenThread(const QString& name, QThread* thread) {
     threadHash[thread] = name;
 }
 
+QString isBlockingForbiddenThread(QThread* currentThread) {
+    QReadLocker locker(&threadHashLock);
+    for (const auto& thread : threadHash.keys()) {
+        if (currentThread == thread) {
+            return threadHash[thread];
+        }
+    }
+    return QString();
+}
+
 bool blockingInvokeMethod(
     const char* function,
     QObject *obj, const char *member,
diff --git a/libraries/shared/src/shared/QtHelpers.h b/libraries/shared/src/shared/QtHelpers.h
index 9a9d33a3ceb..5e317727fd1 100644
--- a/libraries/shared/src/shared/QtHelpers.h
+++ b/libraries/shared/src/shared/QtHelpers.h
@@ -11,14 +11,22 @@
 #define hifi_Shared_QtHelpers_h
 
 #include <QtCore/QObject>
+#include <QtCore/QLoggingCategory>
+#include <QtCore/QThread>
+
+#include "../Profile.h"
 
 #if defined(Q_OS_WIN)
 // Enable event queue debugging
 #define DEBUG_EVENT_QUEUE
 #endif
 
+class QLoggingCategory;
+const QLoggingCategory& thread_safety();
+
 namespace hifi { namespace qt {
 void addBlockingForbiddenThread(const QString& name, QThread* thread = nullptr);
+QString isBlockingForbiddenThread(QThread* currentThread);
 
 bool blockingInvokeMethod(
     const char* function,
@@ -49,6 +57,43 @@ bool blockingInvokeMethod(
     QGenericArgument val8 = QGenericArgument(),
     QGenericArgument val9 = QGenericArgument());
 
+// handling unregistered functions
+template <typename Func, typename ReturnType>
+typename std::enable_if<!std::is_convertible<Func, const char*>::value, bool>::type
+blockingInvokeMethod(const char* callingFunction, QObject* context, Func function, ReturnType* retVal) {
+    auto currentThread = QThread::currentThread();
+    if (currentThread == qApp->thread()) {
+        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on main thread from " << callingFunction;
+        return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection, retVal);
+    }
+
+    QString forbiddenThread = isBlockingForbiddenThread(currentThread);
+    if (!forbiddenThread.isEmpty()) {
+        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on forbidden thread " << forbiddenThread;
+    }
+
+    PROFILE_RANGE(app, callingFunction);
+    return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection, retVal);
+}
+
+template <typename Func>
+typename std::enable_if<!std::is_convertible<Func, const char*>::value, bool>::type
+blockingInvokeMethod(const char* callingFunction, QObject* context, Func function) {
+    auto currentThread = QThread::currentThread();
+    if (currentThread == qApp->thread()) {
+        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on main thread from " << callingFunction;
+        return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection);
+    }
+
+    QString forbiddenThread = isBlockingForbiddenThread(currentThread);
+    if (!forbiddenThread.isEmpty()) {
+        qCWarning(thread_safety) << "BlockingQueuedConnection invoked on forbidden thread " << forbiddenThread;
+    }
+
+    PROFILE_RANGE(app, callingFunction);
+    return QMetaObject::invokeMethod(context, function, Qt::BlockingQueuedConnection);
+}
+
 // Inspecting of the qt event queue
 // requres access to private Qt datastructures
 // Querying the event queue should be done with
diff --git a/libraries/shared/src/shared/ScriptInitializerMixin.h b/libraries/shared/src/shared/ScriptInitializerMixin.h
index 2a7fc10e06e..72f875c392f 100644
--- a/libraries/shared/src/shared/ScriptInitializerMixin.h
+++ b/libraries/shared/src/shared/ScriptInitializerMixin.h
@@ -12,7 +12,6 @@
 #include <mutex>
 #include "../DependencyManager.h"
 
-class QScriptEngine;
 class ScriptEngine;
 
 template <typename T> class ScriptInitializerMixin {
@@ -35,11 +34,11 @@ template <typename T> class ScriptInitializerMixin {
     std::list<ScriptInitializer> _scriptInitializers;
 };
 
-class ScriptInitializers : public ScriptInitializerMixin<QScriptEngine*>, public Dependency {
+class ScriptInitializers : public ScriptInitializerMixin<ScriptEngine*>, public Dependency {
 public:
-    // Lightweight `QScriptEngine*` initializer (only depends on built-in Qt components)
+    // Lightweight `ScriptEngine*` initializer (only depends on built-in Qt components)
     // example registration:
-    // eg: [&](QScriptEngine* engine) {
+    // eg: [&](ScriptEngine* engine) {
     //     engine->globalObject().setProperties("API", engine->newQObject(...instance...))
     // };
 };
diff --git a/libraries/ui/CMakeLists.txt b/libraries/ui/CMakeLists.txt
index 6dde4cc1a20..fce94173f63 100644
--- a/libraries/ui/CMakeLists.txt
+++ b/libraries/ui/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME ui)
-setup_hifi_library(OpenGL Multimedia Network Qml Quick Script WebChannel WebSockets XmlPatterns ${PLATFORM_QT_COMPONENTS})
-link_hifi_libraries(shared networking qml gl audio audio-client plugins pointers)
+setup_hifi_library(OpenGL Multimedia Network Qml Quick WebChannel WebSockets XmlPatterns ${PLATFORM_QT_COMPONENTS})
+link_hifi_libraries(shared networking qml gl audio audio-client plugins pointers script-engine)
 include_hifi_library_headers(controllers)
 
 # Required for some low level GL interaction in the OffscreenQMLSurface
diff --git a/libraries/ui/src/QmlFragmentClass.cpp b/libraries/ui/src/QmlFragmentClass.cpp
index 1219094afcb..b0fe2789605 100644
--- a/libraries/ui/src/QmlFragmentClass.cpp
+++ b/libraries/ui/src/QmlFragmentClass.cpp
@@ -9,18 +9,20 @@
 #include "QmlFragmentClass.h"
 
 #include <QtCore/QThread>
-#include <QtScript/QScriptContext>
-#include <QtScript/QScriptEngine>
 
 #include <shared/QtHelpers.h>
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
 std::mutex QmlFragmentClass::_mutex;
-std::map<QString, QScriptValue> QmlFragmentClass::_fragments;
+std::map<QString, ScriptValue> QmlFragmentClass::_fragments;
 
 QmlFragmentClass::QmlFragmentClass(bool restricted, QString id) : QmlWindowClass(restricted), qml(id) { }
 
 // Method called by Qt scripts to create a new bottom menu bar in Android
-QScriptValue QmlFragmentClass::internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted) {
+ScriptValue QmlFragmentClass::internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted) {
 #ifndef DISABLE_QML
     std::lock_guard<std::mutex> guard(_mutex);
     auto qml = context->argument(0).toVariant().toMap().value("qml");
@@ -33,7 +35,7 @@ QScriptValue QmlFragmentClass::internal_constructor(QScriptContext* context, QSc
         }
     } else {
         qWarning() << "QmlFragmentClass could not build instance " << qml;
-        return QScriptValue();
+        return ScriptValue();
     }
 
     auto properties = parseArguments(context);
@@ -45,12 +47,13 @@ QScriptValue QmlFragmentClass::internal_constructor(QScriptContext* context, QSc
     } else {
         retVal->initQml(properties);
     }
-    connect(engine, &QScriptEngine::destroyed, retVal, &QmlWindowClass::deleteLater);
-    QScriptValue scriptObject = engine->newQObject(retVal);
+    auto manager = engine->manager();
+    connect(manager, &ScriptManager::destroyed, retVal, &QmlWindowClass::deleteLater);
+    ScriptValue scriptObject = engine->newQObject(retVal);
     _fragments[qml.toString()] = scriptObject;
     return scriptObject;
 #else
-    return QScriptValue();
+    return ScriptValue();
 #endif
 }
 
diff --git a/libraries/ui/src/QmlFragmentClass.h b/libraries/ui/src/QmlFragmentClass.h
index c76bb43513e..9c04fe62633 100644
--- a/libraries/ui/src/QmlFragmentClass.h
+++ b/libraries/ui/src/QmlFragmentClass.h
@@ -10,18 +10,22 @@
 #define hifi_ui_QmlFragmentClass_h
 
 #include "QmlWindowClass.h"
+#include <ScriptValue.h>
+
+class ScriptContext;
+class ScriptEngine;
 
 class QmlFragmentClass : public QmlWindowClass {
     Q_OBJECT
 
 private:
-    static QScriptValue internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted);
+    static ScriptValue internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted);
 public: 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine) {
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine) {
         return internal_constructor(context, engine, false);
     }
 
-    static QScriptValue restricted_constructor(QScriptContext* context, QScriptEngine* engine ){
+    static ScriptValue restricted_constructor(ScriptContext* context, ScriptEngine* engine ){
         return internal_constructor(context, engine, true);
     }
 
@@ -46,7 +50,7 @@ public slots:
     QString qmlSource() const override { return qml; }
 
     static std::mutex _mutex;
-    static std::map<QString, QScriptValue> _fragments;
+    static std::map<QString, ScriptValue> _fragments;
 private:
     QString qml;
 
diff --git a/libraries/ui/src/QmlWebWindowClass.cpp b/libraries/ui/src/QmlWebWindowClass.cpp
index c7851d416fe..9fc5ccdf78b 100644
--- a/libraries/ui/src/QmlWebWindowClass.cpp
+++ b/libraries/ui/src/QmlWebWindowClass.cpp
@@ -10,8 +10,9 @@
 
 #include <QtCore/QThread>
 
-#include <QtScript/QScriptContext>
-#include <QtScript/QScriptEngine>
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
 
 #include <shared/QtHelpers.h>
 
@@ -19,7 +20,7 @@ static const char* const URL_PROPERTY = "source";
 static const char* const SCRIPT_PROPERTY = "scriptUrl";
 
 // Method called by Qt scripts to create a new web window in the overlay
-QScriptValue QmlWebWindowClass::internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted) {
+ScriptValue QmlWebWindowClass::internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted) {
     auto properties = parseArguments(context);
     QmlWebWindowClass* retVal = new QmlWebWindowClass(restricted);
     Q_ASSERT(retVal);
@@ -29,7 +30,8 @@ QScriptValue QmlWebWindowClass::internal_constructor(QScriptContext* context, QS
     } else {
         retVal->initQml(properties);
     }
-    connect(engine, &QScriptEngine::destroyed, retVal, &QmlWindowClass::deleteLater);
+    auto manager = engine->manager();
+    connect(manager, &ScriptManager::destroyed, retVal, &QmlWindowClass::deleteLater);
     return engine->newQObject(retVal);
 }
 
diff --git a/libraries/ui/src/QmlWebWindowClass.h b/libraries/ui/src/QmlWebWindowClass.h
index 384bdadfc42..20dadd98bbd 100644
--- a/libraries/ui/src/QmlWebWindowClass.h
+++ b/libraries/ui/src/QmlWebWindowClass.h
@@ -9,8 +9,15 @@
 #ifndef hifi_ui_QmlWebWindowClass_h
 #define hifi_ui_QmlWebWindowClass_h
 
+#include <QtCore/QSharedPointer>
+
 #include "QmlWindowClass.h"
 
+#include <ScriptValue.h>
+
+class ScriptContext;
+class ScriptEngine;
+
 /*@jsdoc
  * A <code>OverlayWebWindow</code> displays an HTML window inside Interface.
  *
@@ -142,15 +149,15 @@ class QmlWebWindowClass : public QmlWindowClass {
     Q_PROPERTY(QString url READ getURL CONSTANT)
 
 private:
-    static QScriptValue internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted);
+    static ScriptValue internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted);
 public:
     QmlWebWindowClass(bool restricted) : QmlWindowClass(restricted) {}
 
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine) {
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine) {
         return internal_constructor(context, engine, false);
     }
 
-    static QScriptValue restricted_constructor(QScriptContext* context, QScriptEngine* engine ){
+    static ScriptValue restricted_constructor(ScriptContext* context, ScriptEngine* engine ){
         return internal_constructor(context, engine, true);
     }
 
diff --git a/libraries/ui/src/QmlWindowClass.cpp b/libraries/ui/src/QmlWindowClass.cpp
index a19b9eb7677..f38dd7723d5 100644
--- a/libraries/ui/src/QmlWindowClass.cpp
+++ b/libraries/ui/src/QmlWindowClass.cpp
@@ -11,8 +11,6 @@
 #include <mutex>
 
 #include <QtCore/QThread>
-#include <QtScript/QScriptContext>
-#include <QtScript/QScriptEngine>
 
 #include <QtQuick/QQuickItem>
 #include <QtQml/QQmlContext>
@@ -27,6 +25,10 @@
 #include "OffscreenUi.h"
 #include "ui/types/HFWebEngineProfile.h"
 #include "ui/types/FileTypeProfile.h"
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
 
 static const char* const SOURCE_PROPERTY = "source";
 static const char* const TITLE_PROPERTY = "title";
@@ -37,7 +39,7 @@ static const char* const VISIBILE_PROPERTY = "visible";
 static const uvec2 MAX_QML_WINDOW_SIZE { 1280, 720 };
 static const uvec2 MIN_QML_WINDOW_SIZE { 120, 80 };
 
-QVariantMap QmlWindowClass::parseArguments(QScriptContext* context) {
+QVariantMap QmlWindowClass::parseArguments(ScriptContext* context) {
     const auto argumentCount = context->argumentCount();
     QVariantMap properties;
     if (argumentCount > 1) {
@@ -70,7 +72,7 @@ QVariantMap QmlWindowClass::parseArguments(QScriptContext* context) {
 
 
 // Method called by Qt scripts to create a new web window in the overlay
-QScriptValue QmlWindowClass::internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted) {
+ScriptValue QmlWindowClass::internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted) {
     auto properties = parseArguments(context);
     QmlWindowClass* retVal = new QmlWindowClass(restricted);
     Q_ASSERT(retVal);
@@ -80,7 +82,8 @@ QScriptValue QmlWindowClass::internal_constructor(QScriptContext* context, QScri
     } else {
         retVal->initQml(properties);
     }
-    connect(engine, &QScriptEngine::destroyed, retVal, &QmlWindowClass::deleteLater);
+    auto manager = engine->manager();
+    connect(manager, &ScriptManager::destroyed, retVal, &QmlWindowClass::deleteLater);
     return engine->newQObject(retVal);
 }
 
diff --git a/libraries/ui/src/QmlWindowClass.h b/libraries/ui/src/QmlWindowClass.h
index e911afea6c5..5d1111bd5ab 100644
--- a/libraries/ui/src/QmlWindowClass.h
+++ b/libraries/ui/src/QmlWindowClass.h
@@ -11,13 +11,13 @@
 
 #include <QtCore/QObject>
 #include <QtCore/QPointer>
-#include <QtScript/QScriptValue>
 #include <QtQuick/QQuickItem>
 
 #include <GLMHelpers.h>
+#include <ScriptValue.h>
 
-class QScriptEngine;
-class QScriptContext;
+class ScriptContext;
+class ScriptEngine;
 
 /*@jsdoc
  * A <code>OverlayWindow</code> displays a QML window inside Interface.
@@ -53,13 +53,13 @@ class QmlWindowClass : public QObject {
     Q_PROPERTY(bool visible READ isVisible WRITE setVisible NOTIFY visibleChanged)
 
 private:
-    static QScriptValue internal_constructor(QScriptContext* context, QScriptEngine* engine, bool restricted);
+    static ScriptValue internal_constructor(ScriptContext* context, ScriptEngine* engine, bool restricted);
 public:
-    static QScriptValue constructor(QScriptContext* context, QScriptEngine* engine) {
+    static ScriptValue constructor(ScriptContext* context, ScriptEngine* engine) {
         return internal_constructor(context, engine, false);
     }
 
-    static QScriptValue restricted_constructor(QScriptContext* context, QScriptEngine* engine ){
+    static ScriptValue restricted_constructor(ScriptContext* context, ScriptEngine* engine ){
         return internal_constructor(context, engine, true);
     }
 
@@ -345,8 +345,8 @@ protected slots:
     void qmlToScript(const QVariant& message);
 
 protected:
-    static QVariantMap parseArguments(QScriptContext* context);
-    static QScriptValue internalConstructor(QScriptContext* context, QScriptEngine* engine, 
+    static QVariantMap parseArguments(ScriptContext* context);
+    static ScriptValue internalConstructor(ScriptContext* context, ScriptEngine* engine, 
         std::function<QmlWindowClass*(QVariantMap)> function);
 
     virtual QString qmlSource() const { return "QmlWindow.qml"; }
diff --git a/libraries/ui/src/ui/OffscreenQmlSurface.h b/libraries/ui/src/ui/OffscreenQmlSurface.h
index 76533a49cbd..7597f7f8fe7 100644
--- a/libraries/ui/src/ui/OffscreenQmlSurface.h
+++ b/libraries/ui/src/ui/OffscreenQmlSurface.h
@@ -13,7 +13,9 @@
 #include <QtGui/qevent.h>
 
 #include <QTouchEvent>
-#include "PointerEvent.h"
+
+#include <ScriptEngine.h>
+#include <PointerEvent.h>
 
 using QmlContextCallback = std::function<void(QQmlContext*)>;
 
diff --git a/libraries/ui/src/ui/QmlWrapper.h b/libraries/ui/src/ui/QmlWrapper.h
index d77e45c9dc0..42091d55490 100644
--- a/libraries/ui/src/ui/QmlWrapper.h
+++ b/libraries/ui/src/ui/QmlWrapper.h
@@ -11,8 +11,11 @@
 
 #include <QtCore/QObject>
 #include <QtCore/QVariant>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptEngine>
+
+#include <ScriptEngine.h>
+#include <ScriptValue.h>
+
+class ScriptEngine;
 
 class QmlWrapper : public QObject {
     Q_OBJECT
@@ -29,16 +32,17 @@ class QmlWrapper : public QObject {
 };
 
 template <typename T>
-QScriptValue wrapperToScriptValue(QScriptEngine* engine, T* const &in) {
+ScriptValue wrapperToScriptValue(ScriptEngine* engine, T* const &in) {
     if (!in) {
         return engine->undefinedValue();
     }
-    return engine->newQObject(in, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects);
+    return engine->newQObject(in, ScriptEngine::QtOwnership);
 }
 
 template <typename T>
-void wrapperFromScriptValue(const QScriptValue& value, T* &out) {
+bool wrapperFromScriptValue(const ScriptValue& value, T* &out) {
     out = qobject_cast<T*>(value.toQObject());
+    return !!out;
 }
 
 #endif
\ No newline at end of file
diff --git a/libraries/ui/src/ui/TabletScriptingInterface.cpp b/libraries/ui/src/ui/TabletScriptingInterface.cpp
index 68730e186fd..81a4e9c7185 100644
--- a/libraries/ui/src/ui/TabletScriptingInterface.cpp
+++ b/libraries/ui/src/ui/TabletScriptingInterface.cpp
@@ -159,6 +159,8 @@ bool TabletButtonsProxyModel::filterAcceptsRow(int sourceRow,
 
 TabletScriptingInterface::TabletScriptingInterface() {
     qmlRegisterType<TabletScriptingInterface>("TabletScriptingInterface", 1, 0, "TabletEnums");
+    qRegisterMetaType<TabletScriptingInterface::TabletAudioEvents>("TabletScriptingInterface::TabletAudioEvents");
+    qRegisterMetaType<TabletScriptingInterface::TabletConstants>("TabletScriptingInterface::TabletConstants");
     qmlRegisterType<TabletButtonsProxyModel>("TabletScriptingInterface", 1, 0, "TabletButtonsProxyModel");
 }
 
diff --git a/libraries/ui/src/ui/TabletScriptingInterface.h b/libraries/ui/src/ui/TabletScriptingInterface.h
index af0c03de80d..4359f72bf16 100644
--- a/libraries/ui/src/ui/TabletScriptingInterface.h
+++ b/libraries/ui/src/ui/TabletScriptingInterface.h
@@ -19,10 +19,6 @@
 #include <QtCore/QAbstractListModel>
 #include <QSortFilterProxyModel>
 
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptValueIterator>
-
 #include <QtQuick/QQuickItem>
 
 #include <glm/glm.hpp>
diff --git a/libraries/ui/src/ui/ToolbarScriptingInterface.cpp b/libraries/ui/src/ui/ToolbarScriptingInterface.cpp
index d01b538004a..c2e908f8a44 100644
--- a/libraries/ui/src/ui/ToolbarScriptingInterface.cpp
+++ b/libraries/ui/src/ui/ToolbarScriptingInterface.cpp
@@ -10,31 +10,31 @@
 
 #include <QtCore/QThread>
 #include <QtQuick/QQuickItem>
-#include <QtScript/QScriptValue>
-#include <QtScript/QScriptEngine>
+#include <ScriptValue.h>
+#include <ScriptEngine.h>
 
 #include <shared/QtHelpers.h>
 #include "../OffscreenUi.h"
 
-QScriptValue toolbarToScriptValue(QScriptEngine* engine, ToolbarProxy* const &in) {
+ScriptValue toolbarToScriptValue(ScriptEngine* engine, ToolbarProxy* const &in) {
     if (!in) {
         return engine->undefinedValue();
     }
-    return engine->newQObject(in, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects);
+    return engine->newQObject(in, ScriptEngine::QtOwnership);
 }
 
-void toolbarFromScriptValue(const QScriptValue& value, ToolbarProxy* &out) {
+void toolbarFromScriptValue(const ScriptValue& value, ToolbarProxy* &out) {
     out = qobject_cast<ToolbarProxy*>(value.toQObject());
 }
 
-QScriptValue toolbarButtonToScriptValue(QScriptEngine* engine, ToolbarButtonProxy* const &in) {
+ScriptValue toolbarButtonToScriptValue(ScriptEngine* engine, ToolbarButtonProxy* const &in) {
     if (!in) {
         return engine->undefinedValue();
     }
-    return engine->newQObject(in, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater | QScriptEngine::ExcludeChildObjects);
+    return engine->newQObject(in, ScriptEngine::QtOwnership);
 }
 
-void toolbarButtonFromScriptValue(const QScriptValue& value, ToolbarButtonProxy* &out) {
+void toolbarButtonFromScriptValue(const ScriptValue& value, ToolbarButtonProxy* &out) {
     out = qobject_cast<ToolbarButtonProxy*>(value.toQObject());
 }
 
diff --git a/libraries/ui/src/ui/ToolbarScriptingInterface.h b/libraries/ui/src/ui/ToolbarScriptingInterface.h
index 5cc847d4428..513d3edbaea 100644
--- a/libraries/ui/src/ui/ToolbarScriptingInterface.h
+++ b/libraries/ui/src/ui/ToolbarScriptingInterface.h
@@ -12,7 +12,6 @@
 #include <mutex>
 
 #include <QtCore/QObject>
-#include <QtScript/QScriptValue>
 
 #include <DependencyManager.h>
 #include "QmlWrapper.h"
diff --git a/plugins/JSAPIExample/CMakeLists.txt b/plugins/JSAPIExample/CMakeLists.txt
index a8fa0a1fd6a..c8858ad2cbb 100644
--- a/plugins/JSAPIExample/CMakeLists.txt
+++ b/plugins/JSAPIExample/CMakeLists.txt
@@ -1,3 +1,4 @@
 set(TARGET_NAME JSAPIExample)
 setup_hifi_client_server_plugin(scripting)
-link_hifi_libraries(shared plugins)
+link_hifi_libraries(shared plugins script-engine)
+include_hifi_library_headers(networking)
diff --git a/plugins/JSAPIExample/src/JSAPIExample.cpp b/plugins/JSAPIExample/src/JSAPIExample.cpp
index 34c28bdf8f8..8dec23fd447 100644
--- a/plugins/JSAPIExample/src/JSAPIExample.cpp
+++ b/plugins/JSAPIExample/src/JSAPIExample.cpp
@@ -17,14 +17,18 @@
 #include <QtCore/QSharedPointer>
 #include <QtCore/QJsonObject>
 #include <QtCore/QLoggingCategory>
+#include <QtCore/QSharedPointer>
 #include <QtCore/QThread>
 #include <QtCore/QTimer>
-#include <QtScript/QScriptEngine>
-#include <QtScript/QScriptable>
 
 #include <SettingHelpers.h>  // for ::settingsFilename()
 #include <SharedUtil.h>      // for ::usecTimestampNow()
 #include <shared/ScriptInitializerMixin.h>
+#include <ScriptContext.h>
+#include <ScriptEngine.h>
+#include <ScriptManager.h>
+#include <ScriptValue.h>
+#include <Scriptable.h>
 
 // NOTE: replace this with your own namespace when starting a new plugin (to avoid .so/.dll symbol clashes)
 namespace REPLACE_ME_WITH_UNIQUE_NAME {
@@ -34,9 +38,9 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
 
     QLoggingCategory logger { "jsapiexample" };
 
-    inline QVariant raiseScriptingError(QScriptContext* context, const QString& message, const QVariant& returnValue = QVariant()) {
+    inline QVariant raiseScriptingError(ScriptContext* context, const QString& message, const QVariant& returnValue = QVariant()) {
         if (context) {
-            // when a QScriptContext is available throw an actual JS Exception (which can be caught using try/catch on JS side)
+            // when a ScriptContext is available throw an actual JS Exception (which can be caught using try/catch on JS side)
             context->throwError(message);
         } else {
             // otherwise just log the error
@@ -47,7 +51,7 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
 
     QObject* createScopedSettings(const QString& scope, QObject* parent, QString& error);
 
-    class JSAPIExample : public QObject, public QScriptable {
+    class JSAPIExample : public QObject, public Scriptable {
         Q_OBJECT
         Q_PLUGIN_METADATA(IID "JSAPIExample" FILE "plugin.json")
         Q_PROPERTY(QString version MEMBER _version CONSTANT)
@@ -60,8 +64,8 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
                 return;
             }
             qCWarning(logger) << "registering w/ScriptInitializerMixin..." << scriptInit.data();
-            scriptInit->registerScriptInitializer([this](QScriptEngine* engine) {
-                auto value = engine->newQObject(this, QScriptEngine::QtOwnership, QScriptEngine::ExcludeDeleteLater);
+            scriptInit->registerScriptInitializer([this](ScriptEngine* engine) {
+                auto value = engine->newQObject(this, ScriptEngine::QtOwnership);
                 engine->globalObject().setProperty(objectName(), value);
                 // qCDebug(logger) << "setGlobalInstance" << objectName() << engine->property("fileName");
             });
@@ -70,7 +74,7 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
 
         // NOTES: everything within the "public slots:" section below will be available from JS via overall plugin QObject
         //    also, to demonstrate future-proofing JS API code, QVariant's are used throughout most of these examples --
-        //    which still makes them very Qt-specific, but avoids depending directly on deprecated QtScript/QScriptValue APIs.
+        //    which still makes them very Qt-specific, but avoids depending directly on deprecated ScriptValue APIs.
         //    (as such this plugin class and its methods remain forward-compatible with other engines like QML's QJSEngine)
 
     public slots:
@@ -146,7 +150,7 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
 
         /**
           * Example of exposing a custom "managed" C++ QObject to JS
-          * The lifecycle of the created QObject* instance becomes managed by the invoking QScriptEngine --
+          * The lifecycle of the created QObject* instance becomes managed by the invoking ScriptEngine --
           * it will be automatically cleaned up once no longer reachable from any JS variables/closures.
           * @example <caption>access persistent settings stored in separate .json files</caption>
           * var settings = JSAPIExample.getScopedSettings("example");
@@ -157,18 +161,22 @@ namespace REPLACE_ME_WITH_UNIQUE_NAME {
           * print("all example::* keys", settings.allKeys());
           * settings = null; // optional best pratice; allows the object to be reclaimed ASAP by the JS garbage collector
           */
-        QScriptValue getScopedSettings(const QString& scope) {
-            auto engine = QScriptable::engine();
+        ScriptValue getScopedSettings(const QString& scope) {
+            auto engine = Scriptable::engine();
             if (!engine) {
-                return QScriptValue::NullValue;
+                return ScriptValue();
+            }
+            auto manager = engine->manager();
+            if (!manager) {
+                return ScriptValue();
             }
             QString error;
-            auto cppValue = createScopedSettings(scope, engine, error);
+            auto cppValue = createScopedSettings(scope, manager, error);
             if (!cppValue) {
                 raiseScriptingError(context(), "error creating scoped settings instance: " + error);
-                return QScriptValue::NullValue;
+                return engine->nullValue();
             }
-            return engine->newQObject(cppValue, QScriptEngine::ScriptOwnership, QScriptEngine::ExcludeDeleteLater);
+            return engine->newQObject(cppValue, ScriptEngine::ScriptOwnership);
         }
 
     private:
diff --git a/plugins/hifiNeuron/CMakeLists.txt b/plugins/hifiNeuron/CMakeLists.txt
index ad4f78698cd..25fd8ff2e54 100644
--- a/plugins/hifiNeuron/CMakeLists.txt
+++ b/plugins/hifiNeuron/CMakeLists.txt
@@ -11,6 +11,7 @@ if (WIN32)
     set(TARGET_NAME hifiNeuron)
     setup_hifi_plugin(Qml)
     link_hifi_libraries(shared controllers qml ui plugins input-plugins)
+    include_hifi_library_headers(script-engine)
     target_neuron()
 
 endif()
diff --git a/plugins/hifiOsc/CMakeLists.txt b/plugins/hifiOsc/CMakeLists.txt
index cb8b437ab6a..78514f5888b 100644
--- a/plugins/hifiOsc/CMakeLists.txt
+++ b/plugins/hifiOsc/CMakeLists.txt
@@ -9,6 +9,7 @@
 set(TARGET_NAME hifiOsc)
 setup_hifi_plugin(Qml)
 link_hifi_libraries(shared controllers ui plugins input-plugins display-plugins)
+include_hifi_library_headers(script-engine)
 target_liblo()
 
 
diff --git a/plugins/hifiSdl2/CMakeLists.txt b/plugins/hifiSdl2/CMakeLists.txt
index e1f0ee28d8b..16ce6f51b4a 100644
--- a/plugins/hifiSdl2/CMakeLists.txt
+++ b/plugins/hifiSdl2/CMakeLists.txt
@@ -16,6 +16,7 @@ if (NOT APPLE)
         link_libraries("-Wl,--allow-multiple-definition")
     endif()
     setup_hifi_plugin(Qml)
-    link_hifi_libraries(shared controllers ui plugins input-plugins script-engine)
+    link_hifi_libraries(shared controllers ui plugins input-plugins)
+    include_hifi_library_headers(script-engine)
     target_sdl2()
 endif()
diff --git a/plugins/oculus/CMakeLists.txt b/plugins/oculus/CMakeLists.txt
index 6ddc75e1e55..2eb7fb48250 100644
--- a/plugins/oculus/CMakeLists.txt
+++ b/plugins/oculus/CMakeLists.txt
@@ -22,6 +22,7 @@ if (WIN32 AND (NOT USE_GLES))
     ${PLATFORM_GL_BACKEND}
   )
   include_hifi_library_headers(octree)
+  include_hifi_library_headers(script-engine)
 
   add_dependency_external_projects(LibOVR)
   find_package(LibOVR REQUIRED)
diff --git a/plugins/openvr/CMakeLists.txt b/plugins/openvr/CMakeLists.txt
index 0b9358242dd..f8e818e7fd3 100644
--- a/plugins/openvr/CMakeLists.txt
+++ b/plugins/openvr/CMakeLists.txt
@@ -11,9 +11,10 @@ if ((WIN32 OR UNIX AND NOT APPLE) AND NOT USE_GLES)
     set(TARGET_NAME openvr)
     setup_hifi_plugin(Gui Qml Multimedia)
     link_hifi_libraries(shared task gl qml networking controllers ui
-        plugins display-plugins ui-plugins input-plugins script-engine
+        plugins display-plugins ui-plugins input-plugins
         audio-client render-utils graphics shaders gpu render material-networking model-networking model-baker hfm model-serializers ktx image procedural ${PLATFORM_GL_BACKEND})
     include_hifi_library_headers(octree)
+    include_hifi_library_headers(script-engine)
 
     target_openvr()
     if (WIN32)
diff --git a/scripts/system/request-service.js b/scripts/system/request-service.js
index b57f2d4cd77..f51931bb3a7 100644
--- a/scripts/system/request-service.js
+++ b/scripts/system/request-service.js
@@ -14,7 +14,7 @@
     // QML has its own XMLHttpRequest, but:
     // - npm request is easier to use.
     // - It is not easy to hack QML's XMLHttpRequest to use our MetaverseServer, and to supply the user's auth when contacting it.
-    //   a. Our custom XMLHttpRequestClass object only works with QScriptEngine, not QML's javascript.
+    //   a. Our custom XMLHttpRequestClass object only works with ScriptEngine, not QML's javascript.
     //   b. We have hacked profiles that intercept requests to our MetavserseServer (providing the correct auth), but those
     //      only work in QML WebEngineView. Setting up communication between ordinary QML and a hiddent WebEngineView is
     //      tantamount to the following anyway, and would still have to duplicate the code from request.js.
diff --git a/tests-manual/controllers/CMakeLists.txt b/tests-manual/controllers/CMakeLists.txt
index 932826c8de1..c200e2fb9ca 100644
--- a/tests-manual/controllers/CMakeLists.txt
+++ b/tests-manual/controllers/CMakeLists.txt
@@ -3,7 +3,7 @@ if (NOT APPLE)
 set(TARGET_NAME controllers-test)
  
 # This is not a testcase -- just set it up as a regular hifi project
-setup_hifi_project(Script Qml)
+setup_hifi_project(Qml)
 set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests/manual-tests/")
 
 setup_memory_debugger()
diff --git a/tests-manual/entities/CMakeLists.txt b/tests-manual/entities/CMakeLists.txt
index a6eed4f2344..1aede6ad6b0 100644
--- a/tests-manual/entities/CMakeLists.txt
+++ b/tests-manual/entities/CMakeLists.txt
@@ -2,7 +2,7 @@
 set(TARGET_NAME "entities-test")
 
 # This is not a testcase -- just set it up as a regular hifi project
-setup_hifi_project(Network Script)
+setup_hifi_project(Network)
 setup_memory_debugger()
 setup_thread_debugger()
 set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests/manual-tests/")
diff --git a/tests-manual/gpu-textures/CMakeLists.txt b/tests-manual/gpu-textures/CMakeLists.txt
index d148b0cd21e..fcade688f95 100644
--- a/tests-manual/gpu-textures/CMakeLists.txt
+++ b/tests-manual/gpu-textures/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME gpu-textures-tests)
 # This is not a testcase -- just set it up as a regular hifi project
-setup_hifi_project(Quick Gui Script)
+setup_hifi_project(Quick Gui)
 setup_memory_debugger()
 setup_thread_debugger()
 set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests/manual-tests/")
diff --git a/tests-manual/gpu/CMakeLists.txt b/tests-manual/gpu/CMakeLists.txt
index dc7bfbe75e0..e72d1672942 100644
--- a/tests-manual/gpu/CMakeLists.txt
+++ b/tests-manual/gpu/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(TARGET_NAME gpu-test)
 # This is not a testcase -- just set it up as a regular hifi project
-setup_hifi_project(Quick Gui Script)
+setup_hifi_project(Quick Gui)
 setup_memory_debugger()
 setup_thread_debugger()
 set_target_properties(${TARGET_NAME} PROPERTIES FOLDER "Tests/manual-tests/")
diff --git a/tests/octree/CMakeLists.txt b/tests/octree/CMakeLists.txt
index 287a3b73d87..49a031887d2 100644
--- a/tests/octree/CMakeLists.txt
+++ b/tests/octree/CMakeLists.txt
@@ -7,4 +7,4 @@ macro (setup_testcase_dependencies)
   package_libraries_for_deployment()
 endmacro ()
 
-setup_hifi_testcase(Script Network)
+setup_hifi_testcase(Network)
diff --git a/tests/physics/CMakeLists.txt b/tests/physics/CMakeLists.txt
index 87e5350c8f8..f47e27226b4 100644
--- a/tests/physics/CMakeLists.txt
+++ b/tests/physics/CMakeLists.txt
@@ -6,4 +6,4 @@ macro (SETUP_TESTCASE_DEPENDENCIES)
   package_libraries_for_deployment()
 endmacro ()
 
-setup_hifi_testcase(Script)
+setup_hifi_testcase()
diff --git a/tools/oven/CMakeLists.txt b/tools/oven/CMakeLists.txt
index 4f48570428b..95206d1ced6 100644
--- a/tools/oven/CMakeLists.txt
+++ b/tools/oven/CMakeLists.txt
@@ -3,6 +3,7 @@ set(TARGET_NAME oven)
 setup_hifi_project(Widgets Gui Concurrent)
 
 link_hifi_libraries(shared shaders image gpu ktx model-serializers hfm baking graphics networking procedural material-networking model-baker task)
+include_hifi_library_headers(script-engine)
 
 setup_memory_debugger()
 setup_thread_debugger()