diff --git a/include/osg/GraphicsContext b/include/osg/GraphicsContext
index 84c261e24..2b3aa4123 100644
--- a/include/osg/GraphicsContext
+++ b/include/osg/GraphicsContext
@@ -108,6 +108,11 @@ class OSG_EXPORT GraphicsContext : public Object
             // V-sync
             bool            vsync;
             
+            // Swap Group
+            bool            swapGroupEnabled;
+            GLuint          swapGroup;
+            GLuint          swapBarrier;
+
             // use multithreaded OpenGL-engine (OS X only)
             bool            useMultiThreadedOpenGLEngine;
             
diff --git a/include/osgViewer/GraphicsWindow b/include/osgViewer/GraphicsWindow
index a2a60e672..e8f04cc9f 100644
--- a/include/osgViewer/GraphicsWindow
+++ b/include/osgViewer/GraphicsWindow
@@ -145,6 +145,14 @@ class OSGVIEWER_EXPORT GraphicsWindow : public osg::GraphicsContext, public osgG
 
         bool getSyncToVBlank() const { return _traits.valid() ? _traits->vsync : true; }
 
+        /** Set swap group. */
+        virtual void setSwapGroup(bool on, GLuint group, GLuint barrier)
+        {
+            osg::notify(osg::NOTICE) << "GraphicsWindow::setSwapGroup(" << on << " " << group << " " << barrier << ") not implemented." << std::endl;
+        }
+
+        void getSwapGroup(bool& on, GLuint& group, GLuint& barrier) const { on = _traits->swapGroupEnabled; group = _traits->swapGroup; barrier = _traits->swapBarrier; }
+
     public:
 
         /** Return whether a valid and usable GraphicsContext has been created.*/
diff --git a/include/osgViewer/api/Win32/GraphicsWindowWin32 b/include/osgViewer/api/Win32/GraphicsWindowWin32
index b10790958..71846ef2a 100644
--- a/include/osgViewer/api/Win32/GraphicsWindowWin32
+++ b/include/osgViewer/api/Win32/GraphicsWindowWin32
@@ -90,6 +90,9 @@ class OSGVIEWER_EXPORT GraphicsWindowWin32 : public osgViewer::GraphicsWindow, p
         /** Set sync-to-vblank. */
         virtual void setSyncToVBlank(bool on);
 
+        /** Set swap group. */
+        virtual void setSwapGroup(bool on, GLuint group, GLuint barrier);
+
         /** Handle a native (Win32) windowing event as received from the system */
         virtual LRESULT handleNativeWindowingEvent( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam );
         
diff --git a/src/osg/GraphicsContext.cpp b/src/osg/GraphicsContext.cpp
index dc41d29e6..cd06b69e4 100644
--- a/src/osg/GraphicsContext.cpp
+++ b/src/osg/GraphicsContext.cpp
@@ -178,6 +178,9 @@ GraphicsContext::Traits::Traits(DisplaySettings* ds):
             face(0),
             mipMapGeneration(false),
             vsync(true),
+            swapGroupEnabled(false),
+            swapGroup(0),
+            swapBarrier(0),
             useMultiThreadedOpenGLEngine(false),
             useCursor(true),
             glContextVersion("1.0"),
diff --git a/src/osgViewer/GraphicsWindowWin32.cpp b/src/osgViewer/GraphicsWindowWin32.cpp
index df0ab6e9b..a060ec01b 100644
--- a/src/osgViewer/GraphicsWindowWin32.cpp
+++ b/src/osgViewer/GraphicsWindowWin32.cpp
@@ -1815,7 +1815,7 @@ bool GraphicsWindowWin32::realizeImplementation()
         if (!_initialized) return false;
     }
 
-    if (_traits.valid() && (_traits->sharedContext /*|| _traits->vsync*/))
+    if (_traits.valid() && (_traits->sharedContext || _traits->vsync || _traits->swapGroupEnabled))
     {
         // make context current so we can test capabilities and set up context sharing
         struct RestoreContext
@@ -1827,10 +1827,7 @@ bool GraphicsWindowWin32::realizeImplementation()
             }
             ~RestoreContext()
             {
-                if (_hdc)
-                {
-                    wglMakeCurrent(_hdc,_hglrc);
-                }
+                wglMakeCurrent(_hdc,_hglrc);
             }
         protected:
             HDC      _hdc;
@@ -1862,6 +1859,12 @@ bool GraphicsWindowWin32::realizeImplementation()
         {
             setSyncToVBlank(_traits->vsync);
         }
+
+        // If the swap group is active then enable it.
+        if (_traits->swapGroupEnabled)
+        {
+            setSwapGroup(_traits->swapGroupEnabled, _traits->swapGroup, _traits->swapBarrier);
+        }
     }
 
     if (_ownsWindow)
@@ -2207,6 +2210,36 @@ HCURSOR GraphicsWindowWin32::getOrCreateCursor(MouseCursor mouseCursor)
     return _mouseCursorMap[mouseCursor];
 }
 
+void GraphicsWindowWin32::setSwapGroup(bool on, GLuint group, GLuint barrier)
+{
+    if (_traits.valid())
+    {
+        _traits->swapGroupEnabled = on;
+        _traits->swapGroup        = group;
+        _traits->swapBarrier      = barrier;
+    }
+
+    typedef BOOL (GL_APIENTRY *PFNWGLJOINSWAPGROUPNVPROC) (HDC hDC, GLuint group);
+    PFNWGLJOINSWAPGROUPNVPROC wglJoinSwapGroupNV = (PFNWGLJOINSWAPGROUPNVPROC)wglGetProcAddress( "wglJoinSwapGroupNV" );
+
+    typedef BOOL (GL_APIENTRY *PFNWGLBINDSWAPBARRIERNVPROC) (GLuint group, GLuint barrier);
+    PFNWGLBINDSWAPBARRIERNVPROC wglBindSwapBarrierNV = (PFNWGLBINDSWAPBARRIERNVPROC)wglGetProcAddress( "wglBindSwapBarrierNV" );
+
+    if ((!wglJoinSwapGroupNV) || (!wglBindSwapBarrierNV))
+    {
+        OSG_INFO << "GraphicsWindowWin32::wglJoinSwapGroupNV(bool, GLuint, GLuint) not supported" << std::endl;
+        return;
+    }
+
+    int swapGroup = (on ? group : 0);
+    BOOL resultJoin = wglJoinSwapGroupNV(_hdc, swapGroup);
+    OSG_INFO << "GraphicsWindowWin32::wglJoinSwapGroupNV (" << swapGroup << ") returned " << resultJoin << std::endl;
+
+    int swapBarrier = (on ? barrier : 0);
+    BOOL resultBind = wglBindSwapBarrierNV(swapGroup, swapBarrier);
+    OSG_INFO << "GraphicsWindowWin32::wglBindSwapBarrierNV (" << swapGroup << ", " << swapBarrier << ") returned " << resultBind << std::endl;
+}
+
 void GraphicsWindowWin32::setSyncToVBlank( bool on )
 {
     if (_traits.valid())
@@ -2214,7 +2247,7 @@ void GraphicsWindowWin32::setSyncToVBlank( bool on )
         _traits->vsync = on;
     }
 
-#if 0
+//#if 0
     // we ought to properly check if the extension is listed as supported rather than just
     // if the function pointer resolves through wglGetProcAddress, but in practice everything
     // supports this extension
@@ -2232,9 +2265,9 @@ void GraphicsWindowWin32::setSyncToVBlank( bool on )
     {
         OSG_INFO << "GraphicsWindowWin32::setSyncToVBlank(bool) not supported" << std::endl;
     }
-#else
-    OSG_INFO << "GraphicsWindowWin32::setSyncToVBlank(bool) not yet implemented."<< std::endl;
-#endif
+//#else
+//    OSG_INFO << "GraphicsWindowWin32::setSyncToVBlank(bool) not yet implemented."<< std::endl;
+//#endif
 }
 
 void GraphicsWindowWin32::adaptKey( WPARAM wParam, LPARAM lParam, int& keySymbol, unsigned int& modifierMask, int& unmodifiedKeySymbol)