diff --git a/HostSupport/examples/hostDemoEffectInstance.cpp b/HostSupport/examples/hostDemoEffectInstance.cpp
index db8652f04..d253fd6b3 100755
--- a/HostSupport/examples/hostDemoEffectInstance.cpp
+++ b/HostSupport/examples/hostDemoEffectInstance.cpp
@@ -164,7 +164,9 @@ namespace MyHost {
   // make a parameter instance
   OFX::Host::Param::Instance* MyEffectInstance::newParam(const std::string& name, OFX::Host::Param::Descriptor& descriptor)
   {
-    if(descriptor.getType()==kOfxParamTypeInteger)
+    if(descriptor.getType()==kOfxParamTypeString)
+      return new MyStringInstance(this,name,descriptor);
+    else if(descriptor.getType()==kOfxParamTypeInteger)
       return new MyIntegerInstance(this,name,descriptor);
     else if(descriptor.getType()==kOfxParamTypeDouble)
       return new MyDoubleInstance(this,name,descriptor);
@@ -172,6 +174,10 @@ namespace MyHost {
       return new MyBooleanInstance(this,name,descriptor);
     else if(descriptor.getType()==kOfxParamTypeChoice)
       return new MyChoiceInstance(this,name,descriptor);
+#ifdef OFX_EXTENSIONS_RESOLVE
+    else if(descriptor.getType()==kOfxParamTypeStrChoice)
+      return new MyStrChoiceInstance(this,name,descriptor);
+#endif
     else if(descriptor.getType()==kOfxParamTypeRGBA)
       return new MyRGBAInstance(this,name,descriptor);
     else if(descriptor.getType()==kOfxParamTypeRGB)
diff --git a/HostSupport/examples/hostDemoParamInstance.cpp b/HostSupport/examples/hostDemoParamInstance.cpp
index 3906e420b..9da444754 100755
--- a/HostSupport/examples/hostDemoParamInstance.cpp
+++ b/HostSupport/examples/hostDemoParamInstance.cpp
@@ -55,6 +55,37 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace MyHost {
 
+  //
+  // MyStringInstance
+  //
+
+  MyStringInstance::MyStringInstance(MyEffectInstance* effect,
+                                     const std::string& name,
+                                     OFX::Host::Param::Descriptor& descriptor)
+    : OFX::Host::Param::StringInstance(descriptor), _effect(effect), _descriptor(descriptor)
+  {
+  }
+
+  OfxStatus MyStringInstance::get(std::string&)
+  {
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStringInstance::get(OfxTime time, std::string&)
+  {
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStringInstance::set(const char*)
+  {
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStringInstance::set(OfxTime time, const char*)
+  {
+    return kOfxStatOK;
+  }
+
   //
   // MyIntegerInstance
   //
@@ -64,25 +95,31 @@ namespace MyHost {
                                        OFX::Host::Param::Descriptor& descriptor)
     : OFX::Host::Param::IntegerInstance(descriptor), _effect(effect), _descriptor(descriptor)
   {
+    _i = getProperties().getIntProperty(kOfxParamPropDefault);
   }
 
-  OfxStatus MyIntegerInstance::get(int&)
+  OfxStatus MyIntegerInstance::get(int& i)
   {
-    return kOfxStatErrMissingHostFeature;
+    i = _i;
+    return kOfxStatOK;
   }
 
-  OfxStatus MyIntegerInstance::get(OfxTime time, int&)
+  OfxStatus MyIntegerInstance::get(OfxTime time, int& i)
   {
-    return kOfxStatErrMissingHostFeature;
+    i = _i;
+    return kOfxStatOK;
   }
 
-  OfxStatus MyIntegerInstance::set(int)
+  OfxStatus MyIntegerInstance::set(int i)
   {
-    return kOfxStatErrMissingHostFeature;
+    _i = i;
+    return kOfxStatOK;
   }
 
-  OfxStatus MyIntegerInstance::set(OfxTime time, int) {
-    return kOfxStatErrMissingHostFeature;
+  OfxStatus MyIntegerInstance::set(OfxTime time, int i)
+  {
+    _i = i;
+    return kOfxStatOK;
   }
 
   //
@@ -94,40 +131,41 @@ namespace MyHost {
                                      OFX::Host::Param::Descriptor& descriptor)
     : OFX::Host::Param::DoubleInstance(descriptor), _effect(effect), _descriptor(descriptor)
   {
+    _d = getProperties().getDoubleProperty(kOfxParamPropDefault);
   }
 
   OfxStatus MyDoubleInstance::get(double& d)
   {
-    // values for the Basic OFX plugin to work
-    d = 2.0;
+    d = _d;
     return kOfxStatOK;
   }
 
   OfxStatus MyDoubleInstance::get(OfxTime time, double& d)
   {
-    // values for the Basic OFX plugin to work
-    d = 2.0;
+    d = _d;
     return kOfxStatOK;
   }
 
-  OfxStatus MyDoubleInstance::set(double)
+  OfxStatus MyDoubleInstance::set(double d)
   {
-    return kOfxStatErrMissingHostFeature;
+    _d = d;
+    return kOfxStatOK;
   }
 
-  OfxStatus MyDoubleInstance::set(OfxTime time, double) 
+  OfxStatus MyDoubleInstance::set(OfxTime time, double d)
   {
-    return kOfxStatErrMissingHostFeature;
+    _d = d;
+    return kOfxStatOK;
   }
 
   OfxStatus MyDoubleInstance::derive(OfxTime time, double&)
   {
-    return kOfxStatErrMissingHostFeature;
+    return kOfxStatOK;
   }
 
   OfxStatus MyDoubleInstance::integrate(OfxTime time1, OfxTime time2, double&)
   {
-    return kOfxStatErrMissingHostFeature;
+    return kOfxStatOK;
   }
 
   //
@@ -139,31 +177,73 @@ namespace MyHost {
                                        OFX::Host::Param::Descriptor& descriptor)
     : OFX::Host::Param::BooleanInstance(descriptor), _effect(effect), _descriptor(descriptor)
   {
+    _b = getProperties().getIntProperty(kOfxParamPropDefault);
   }
 
   OfxStatus MyBooleanInstance::get(bool& b)
   {
-    b = true;
+    b = _b;
     return kOfxStatOK;
   }
 
   OfxStatus MyBooleanInstance::get(OfxTime time, bool& b)
   {
-    b = true;
+    b = _b;
     return kOfxStatOK;
   }
 
-  OfxStatus MyBooleanInstance::set(bool)
+  OfxStatus MyBooleanInstance::set(bool b)
   {
-    return kOfxStatErrMissingHostFeature;
+    _b = b;
+    return kOfxStatOK;
   }
 
-  OfxStatus MyBooleanInstance::set(OfxTime time, bool) {
-    return kOfxStatErrMissingHostFeature;
+  OfxStatus MyBooleanInstance::set(OfxTime time, bool b)
+  {
+    _b = b;
+    return kOfxStatOK;
+  }
+
+#ifdef OFX_EXTENSIONS_RESOLVE
+  //
+  // MyStrChoiceInstance
+  //
+
+  MyStrChoiceInstance::MyStrChoiceInstance(MyEffectInstance* effect,
+                                     const std::string& name,
+                                     OFX::Host::Param::Descriptor& descriptor)
+    : OFX::Host::Param::StrChoiceInstance(descriptor), _effect(effect), _descriptor(descriptor)
+  {
+      _choice = getProperties().getStringProperty(kOfxParamPropDefault);
+  }
+
+  OfxStatus MyStrChoiceInstance::get(std::string& choice)
+  {
+    choice = _choice;
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStrChoiceInstance::get(OfxTime time, std::string& choice)
+  {
+    choice = _choice;
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStrChoiceInstance::set(const char* choice)
+  {
+    _choice = std::string(choice);
+    return kOfxStatOK;
+  }
+
+  OfxStatus MyStrChoiceInstance::set(OfxTime time, const char* choice)
+  {
+    _choice = std::string(choice);
+    return kOfxStatOK;
   }
+#endif
 
   //
-  // MyChoiceInteger
+  // MyChoiceInstance
   //
 
   MyChoiceInstance::MyChoiceInstance(MyEffectInstance* effect, 
diff --git a/HostSupport/examples/hostDemoParamInstance.h b/HostSupport/examples/hostDemoParamInstance.h
index 8ff778ae7..b6935e16b 100755
--- a/HostSupport/examples/hostDemoParamInstance.h
+++ b/HostSupport/examples/hostDemoParamInstance.h
@@ -39,7 +39,20 @@ namespace MyHost {
     MyPushbuttonInstance(MyEffectInstance* effect, const std::string& name, OFX::Host::Param::Descriptor& descriptor);
   };
 
+  class MyStringInstance : public OFX::Host::Param::StringInstance {
+  protected:
+    MyEffectInstance*   _effect;
+    OFX::Host::Param::Descriptor& _descriptor;
+  public:
+    MyStringInstance(MyEffectInstance* effect, const std::string& name, OFX::Host::Param::Descriptor& descriptor);
+    OfxStatus get(std::string&);
+    OfxStatus get(OfxTime time, std::string&);
+    OfxStatus set(const char*);
+    OfxStatus set(OfxTime time, const char*);
+  };
+
   class MyIntegerInstance : public OFX::Host::Param::IntegerInstance {
+    int _i;
   protected:
     MyEffectInstance*   _effect;
     OFX::Host::Param::Descriptor& _descriptor;
@@ -52,6 +65,7 @@ namespace MyHost {
   };
 
   class MyDoubleInstance : public OFX::Host::Param::DoubleInstance {
+    double _d;
   protected:
     MyEffectInstance*   _effect;
     OFX::Host::Param::Descriptor& _descriptor;
@@ -66,6 +80,7 @@ namespace MyHost {
   };
 
   class MyBooleanInstance : public OFX::Host::Param::BooleanInstance {
+    bool _b;
   protected:
     MyEffectInstance*   _effect;
     OFX::Host::Param::Descriptor& _descriptor;
@@ -89,6 +104,21 @@ namespace MyHost {
     OfxStatus set(OfxTime time, int);
   };
 
+#ifdef OFX_EXTENSIONS_RESOLVE
+  class MyStrChoiceInstance : public OFX::Host::Param::StrChoiceInstance {
+    std::string _choice;
+  protected:
+    MyEffectInstance*   _effect;
+    OFX::Host::Param::Descriptor& _descriptor;
+  public:
+    MyStrChoiceInstance(MyEffectInstance* effect,  const std::string& name, OFX::Host::Param::Descriptor& descriptor);
+    OfxStatus get(std::string&);
+    OfxStatus get(OfxTime time, std::string&);
+    OfxStatus set(const char*);
+    OfxStatus set(OfxTime time, const char*);
+  };
+#endif
+
   class MyRGBAInstance : public OFX::Host::Param::RGBAInstance {
   protected:
     MyEffectInstance*   _effect;
diff --git a/HostSupport/include/ofxhParam.h b/HostSupport/include/ofxhParam.h
index 5e86b47d8..af784ce85 100755
--- a/HostSupport/include/ofxhParam.h
+++ b/HostSupport/include/ofxhParam.h
@@ -377,6 +377,38 @@ namespace OFX {
         virtual void notify(const std::string &name, bool single, int num) OFX_EXCEPTION_SPEC;
       };
 
+#ifdef OFX_EXTENSIONS_RESOLVE
+      class StrChoiceInstance : public Instance, public KeyframeParam {
+        std::string _returnValue; ///< location to hold temporary return value. Should delegate this to implementation!!!
+      public:
+        StrChoiceInstance(Descriptor& descriptor, Param::SetInstance* instance = 0);
+
+        // callback which should set option as appropriate
+        virtual void setOption(int num);
+
+        // Deriving implementatation needs to overide these
+        virtual OfxStatus get(std::string &) = 0;
+        virtual OfxStatus get(OfxTime time, std::string &) = 0;
+        virtual OfxStatus set(const char*) = 0;
+        virtual OfxStatus set(OfxTime time, const char*) = 0;
+
+        /// implementation of var args function
+        virtual OfxStatus getV(va_list arg);
+
+        /// implementation of var args function
+        virtual OfxStatus getV(OfxTime time, va_list arg);
+
+        /// implementation of var args function
+        virtual OfxStatus setV(va_list arg);
+
+        /// implementation of var args function
+        virtual OfxStatus setV(OfxTime time, va_list arg);
+
+        /// overridden from Instance
+        virtual void notify(const std::string &name, bool single, int num) OFX_EXCEPTION_SPEC;
+      };
+#endif
+
       class DoubleInstance : public Instance, public KeyframeParam {
       public:
         DoubleInstance(Descriptor& descriptor, Param::SetInstance* instance = 0) : Instance(descriptor,instance) {}
diff --git a/HostSupport/src/ofxhImageEffect.cpp b/HostSupport/src/ofxhImageEffect.cpp
index 84f023775..e156e4c88 100644
--- a/HostSupport/src/ofxhImageEffect.cpp
+++ b/HostSupport/src/ofxhImageEffect.cpp
@@ -111,6 +111,8 @@ namespace OFX {
 #ifdef OFX_EXTENSIONS_RESOLVE
         { kOfxImageEffectPropOpenCLRenderSupported, Property::eString, 1, false, "false"},
         { kOfxImageEffectPropCudaRenderSupported, Property::eString, 1, false, "false" },
+        { kOfxImageEffectPropCudaStreamSupported, Property::eString, 1, false, "false" },
+        { kOfxImageEffectPropMetalRenderSupported, Property::eString, 1, false, "false" },
 #endif
 #ifdef OFX_EXTENSIONS_NUKE
         { kFnOfxImageEffectPropMultiPlanar,   Property::eInt, 1, false, "0" },
@@ -1301,7 +1303,10 @@ namespace OFX {
 #       ifdef OFX_EXTENSIONS_RESOLVE
           { kOfxImageEffectPropOpenCLEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropCudaEnabled, Property::eInt, 1, true, "0" },
+          { kOfxImageEffectPropMetalEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropOpenCLCommandQueue, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropCudaStream, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropMetalCommandQueue, Property::ePointer, 1, false, "0" },
 #       endif
 #       ifdef OFX_EXTENSIONS_NUKE
           { kFnOfxImageEffectPropView, Property::eInt, 1, true, "0" },
@@ -1401,7 +1406,10 @@ namespace OFX {
 #       ifdef OFX_EXTENSIONS_RESOLVE
           { kOfxImageEffectPropOpenCLEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropCudaEnabled, Property::eInt, 1, true, "0" },
+          { kOfxImageEffectPropMetalEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropOpenCLCommandQueue, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropCudaStream, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropMetalCommandQueue, Property::ePointer, 1, false, "0" },
 #       endif
 #       ifdef OFX_EXTENSIONS_VEGAS
           { kOfxImageEffectPropRenderView, Property::eInt, 1, true, "0" },
@@ -1518,7 +1526,10 @@ namespace OFX {
 #       ifdef OFX_EXTENSIONS_RESOLVE
           { kOfxImageEffectPropOpenCLEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropCudaEnabled, Property::eInt, 1, true, "0" },
+          { kOfxImageEffectPropMetalEnabled, Property::eInt, 1, true, "0" },
           { kOfxImageEffectPropOpenCLCommandQueue, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropCudaStream, Property::ePointer, 1, false, "0" },
+          { kOfxImageEffectPropMetalCommandQueue, Property::ePointer, 1, false, "0" },
 #       endif
 #       ifdef OFX_EXTENSIONS_NUKE
           { kFnOfxImageEffectPropView, Property::eInt, 1, true, "0" },
@@ -4199,6 +4210,8 @@ namespace OFX {
 #     ifdef OFX_EXTENSIONS_RESOLVE
         { kOfxImageEffectPropOpenCLRenderSupported, Property::eString, 1, false, "false"},
         { kOfxImageEffectPropCudaRenderSupported, Property::eString, 1, false, "false" },
+        { kOfxImageEffectPropCudaStreamSupported, Property::eString, 1, false, "false" },
+        { kOfxImageEffectPropMetalRenderSupported, Property::eString, 1, false, "false" },
 #     endif
 #     ifdef OFX_EXTENSIONS_NUKE
         { kFnOfxImageEffectPropMultiPlanar,   Property::eInt, 1, false, "0" },
diff --git a/HostSupport/src/ofxhImageEffectAPI.cpp b/HostSupport/src/ofxhImageEffectAPI.cpp
index 1f031f0c8..2c755475e 100644
--- a/HostSupport/src/ofxhImageEffectAPI.cpp
+++ b/HostSupport/src/ofxhImageEffectAPI.cpp
@@ -282,10 +282,11 @@ namespace OFX {
 #           ifdef OFX_DEBUG_ACTIONS
               OfxPlugin *op = _pluginHandle->getOfxPlugin();
               std::cout << "OFX: "<<op->pluginIdentifier<<"("<<(void*)op<<")->"<<kOfxActionUnload<<"()"<<std::endl;
+              std::string pluginIdentifier(op->pluginIdentifier); // save it before it becomes invalid
 #           endif
             stat = (*_pluginHandle)->mainEntry(kOfxActionUnload, 0, 0, 0);
 #           ifdef OFX_DEBUG_ACTIONS
-              std::cout << "OFX: "<<op->pluginIdentifier<<"("<<(void*)op<<")->"<<kOfxActionUnload<<"()->"<<StatStr(stat)<<std::endl;
+              std::cout << "OFX: "<<pluginIdentifier<<"("<<(void*)op<<")->"<<kOfxActionUnload<<"()->"<<StatStr(stat)<<std::endl;
 #           endif
           } CatchAllSetStatus(stat, gImageEffectHost, (*_pluginHandle), kOfxActionUnload);
           (void)stat;
diff --git a/HostSupport/src/ofxhParam.cpp b/HostSupport/src/ofxhParam.cpp
index 785a291d0..a886ac457 100644
--- a/HostSupport/src/ofxhParam.cpp
+++ b/HostSupport/src/ofxhParam.cpp
@@ -999,7 +999,7 @@ namespace OFX {
 #       endif
         return set(time, value);
       }
-      
+
       /// overridden from Instance
       void ChoiceInstance::notify(const std::string &name, bool single, int num) OFX_EXCEPTION_SPEC
       {
@@ -1010,9 +1010,86 @@ namespace OFX {
       }
 
 #ifdef OFX_EXTENSIONS_RESOLVE
-#ifdef __GNUC__
-#warning "TODO: StrChoiceInstance"
-#endif
+      //
+      // StrChoiceInstance
+      //
+
+      /// make a parameter, with the given type and name
+      StrChoiceInstance::StrChoiceInstance(Descriptor& descriptor, Param::SetInstance* instance)
+        : Instance(descriptor,instance)
+      {
+        _properties.addNotifyHook(kOfxParamPropChoiceOption, this);
+      }
+
+      // callback which should set option as appropriate
+      void StrChoiceInstance::setOption(int /*num*/)
+      {
+      }
+
+      /// implementation of var args function
+      OfxStatus StrChoiceInstance::getV(va_list arg)
+      {
+        const char **value = va_arg(arg, const char **);
+
+        OfxStatus stat = get(_returnValue); // I so don't like this, temp storage should be delegated to the implementation
+        *value = _returnValue.c_str();
+#       ifdef OFX_DEBUG_PARAMETERS
+        if (stat == kOfxStatOK) {
+          std::cout << ' ' << *value;
+        }
+#       endif
+        return stat;
+      }
+
+      /// implementation of var args function
+      OfxStatus StrChoiceInstance::getV(OfxTime time, va_list arg)
+      {
+        if ( OFX::IsNaN(time) ) {
+          return kOfxStatErrValue;
+        }
+        const char **value = va_arg(arg, const char **);
+
+        OfxStatus stat = get(time, _returnValue); // I so don't like this, temp storage should be delegated to the implementation
+        *value = _returnValue.c_str();
+#       ifdef OFX_DEBUG_PARAMETERS
+        if (stat == kOfxStatOK) {
+          std::cout << ' ' << *value;
+        }
+#       endif
+        return stat;
+      }
+
+      /// implementation of var args function
+      OfxStatus StrChoiceInstance::setV(va_list arg)
+      {
+        char *value = va_arg(arg, char*);
+#       ifdef OFX_DEBUG_PARAMETERS
+        std::cout << value;
+#       endif
+        return set(value);
+      }
+
+      /// implementation of var args function
+      OfxStatus StrChoiceInstance::setV(OfxTime time, va_list arg)
+      {
+        if ( OFX::IsNaN(time) ) {
+          return kOfxStatErrValue;
+        }
+        char *value = va_arg(arg, char*);
+#       ifdef OFX_DEBUG_PARAMETERS
+        std::cout << value;
+#       endif
+        return set(time, value);
+      }
+
+      /// overridden from Instance
+      void StrChoiceInstance::notify(const std::string &name, bool single, int num) OFX_EXCEPTION_SPEC
+      {
+        Instance::notify(name, single, num);
+        if (name == kOfxParamPropChoiceOption) {
+          setOption(num);
+        }
+      }
 #endif
 
       //
@@ -2364,7 +2441,7 @@ namespace OFX {
 
         va_end(ap);
 
-        if (stat == kOfxStatOK) {
+        if (stat == kOfxStatOK && paramInstance->getParamSetInstance()) {
           paramInstance->getParamSetInstance()->paramChangedByPlugin(paramInstance);
         }
 
@@ -2405,7 +2482,7 @@ namespace OFX {
 
         va_end(ap);
 
-        if (stat == kOfxStatOK) {
+        if (stat == kOfxStatOK && paramInstance->getParamSetInstance()) {
           paramInstance->getParamSetInstance()->paramChangedByPlugin(paramInstance);
         }
 
diff --git a/include/ofxImageEffect.h b/include/ofxImageEffect.h
index 59bbd0a88..22cac73bf 100644
--- a/include/ofxImageEffect.h
+++ b/include/ofxImageEffect.h
@@ -1474,6 +1474,29 @@ using the buffer pointers.
 */
 #define kOfxImageEffectPropCudaEnabled "OfxImageEffectPropCudaEnabled"
 
+/**  @brief Indicates whether a host or plugin can support Cuda stream
+
+    - Type - string X 1
+    - Property Set - plugin descriptor (read/write), host descriptor (read only)
+    - Default - "false"
+    - Valid Values - This must be one of
+      - "false"  - in which case the host or plugin does not support Cuda stream
+      - "true"   - which means a host or plugin can support Cuda stream provided
+
+*/
+#define kOfxImageEffectPropCudaStreamSupported "OfxImageEffectPropCudaStreamSupported"
+
+/**  @brief The stream of Cuda render
+
+    - Type - pointer X 1
+    - Property Set - plugin descriptor (read only), host descriptor (read/write)
+
+This property contains a pointer to the stream of Cuda render (cudaStream_t).
+In order to use it, reinterpret_cast<cudaStream_t>(pointer) is needed.
+
+*/
+#define kOfxImageEffectPropCudaStream "OfxImageEffectPropCudaStream"
+
 /** @brief Indicates whether a host or plugin can support Metal render
 
     - Type - string X 1