diff --git a/freeglut/freeglut/src/freeglut_internal.h b/freeglut/freeglut/src/freeglut_internal.h
index a97e029..3d73efc 100644
--- a/freeglut/freeglut/src/freeglut_internal.h
+++ b/freeglut/freeglut/src/freeglut_internal.h
@@ -341,6 +341,8 @@ struct tagSFG_Context
 
 #if TARGET_HOST_UNIX_X11
     XVisualInfo*    VisualInfo;      /* The window's visual information     */
+    Pixmap          Pixmap;          /* Used for offscreen rendering        */
+    //GLXPixmap       GLXPixMap;       /* Used for offscreen rendering        */
 #elif TARGET_HOST_WIN32
     HDC             Device;          /* The window's device context         */
 #endif
@@ -370,8 +372,8 @@ struct tagSFG_WindowState
     int             MouseX, MouseY;     /* The most recent mouse position    */
 
     GLboolean       IsGameMode;         /* Is this the game mode window?     */
-
     GLboolean       NeedToResize;       /* Do we need to resize the window?  */
+    GLboolean       IsOffscreen;        /* Tags a `window' as on/offscreen.  */
 };
 
 
diff --git a/freeglut/freeglut/src/freeglut_window.c b/freeglut/freeglut/src/freeglut_window.c
index 12e6b52..f99b673 100644
--- a/freeglut/freeglut/src/freeglut_window.c
+++ b/freeglut/freeglut/src/freeglut_window.c
@@ -267,30 +267,30 @@ void fgOpenWindow( SFG_Window* window, const char* title,
      * XXX With a little thought, we should be able to greatly
      * XXX simplify this.
      */
-    if ( !window->IsMenu )
-      window->Window.VisualInfo = fgChooseVisual();
-    else if ( fgStructure.MenuContext )
-        window->Window.VisualInfo = fgChooseVisual();
+    if( !window->IsMenu )
+	window->Window.VisualInfo = fgChooseVisual( );
+    else if( fgStructure.MenuContext )
+        window->Window.VisualInfo = fgChooseVisual( );
     else
     {
         unsigned int current_DisplayMode = fgState.DisplayMode ;
         fgState.DisplayMode = GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH ;
-        window->Window.VisualInfo = fgChooseVisual();
+        window->Window.VisualInfo = fgChooseVisual( );
         fgState.DisplayMode = current_DisplayMode ;
     }
 
-    if ( ! window->Window.VisualInfo )
+    if( ! window->Window.VisualInfo )
     {
         /*
          * The "fgChooseVisual" returned a null meaning that the visual
          * context is not available.
          * Try a couple of variations to see if they will work.
          */
-        if ( ! ( fgState.DisplayMode & GLUT_DOUBLE ) )
+        if( !( fgState.DisplayMode & GLUT_DOUBLE ) )
         {
             fgState.DisplayMode |= GLUT_DOUBLE ;
-            window->Window.VisualInfo = fgChooseVisual();
-            fgState.DisplayMode &= ~GLUT_DOUBLE ;
+            window->Window.VisualInfo = fgChooseVisual( );
+            fgState.DisplayMode &= ~GLUT_DOUBLE;
         }
         
         /*
@@ -299,66 +299,95 @@ void fgOpenWindow( SFG_Window* window, const char* title,
          */
     }
 
+    /*
+     * XXX This seems to be abusing an assert() for error-checking.
+     * XXX It is possible that the visual simply can't be found,
+     * XXX in which case we should print an error and return a 0
+     * XXX for the window id, I think.
+     */
     assert( window->Window.VisualInfo != NULL );
 
-    /*
-     * XXX HINT: the masks should be updated when adding/removing callbacks.
-     * XXX       This might speed up message processing. Is that true?
-     * XXX
-     * XXX A: Not appreciably, but it WILL make it easier to debug.
-     * XXX    Try tracing old GLUT and try tracing freeglut.  Old GLUT
-     * XXX    turns off events that it doesn't need and is a whole lot
-     * XXX    more pleasant to trace.  (Hint: Think mouse-motion!)
-     * XXX
-     * XXX    It may make a difference in networked environments or on
-     * XXX    some very slow systems, but I think that that is secondary
-     * XXX    to making debugging easier.
-     */
-    winAttr.event_mask        = StructureNotifyMask | SubstructureNotifyMask |
-        ExposureMask | ButtonPressMask | ButtonReleaseMask | KeyPressMask |
-        KeyRelease | VisibilityChangeMask | EnterWindowMask | LeaveWindowMask |
-        PointerMotionMask | ButtonMotionMask;
-    winAttr.background_pixmap = None;
-    winAttr.background_pixel  = 0;
-    winAttr.border_pixel      = 0;
-
-    winAttr.colormap = XCreateColormap(
-        fgDisplay.Display, fgDisplay.RootWindow,
-        window->Window.VisualInfo->visual, AllocNone
-    );
-
-    mask = CWBackPixmap | CWBorderPixel | CWColormap | CWEventMask;
-
-    if ( window->IsMenu )
+    window->State.IsOffscreen = GL_FALSE;
+    if( fgState.DisplayMode & GLUT_OFFSCREEN )
     {
-        winAttr.override_redirect = True;
-        mask |= CWOverrideRedirect;
+	window->State.IsOffscreen = GL_TRUE;
+        window->Window.Pixmap = XCreatePixmap(
+            fgDisplay.Display, fgDisplay.RootWindow,
+            w, h,
+            window->Window.VisualInfo->depth
+        );
+        if( False != window->Window.Pixmap )
+        {
+            window->Window.Handle = glXCreateGLXPixmap(
+                fgDisplay.Display,
+                window->Window.VisualInfo,
+                window->Window.Pixmap
+            );
+            if( False == window->Window.Handle )
+                XFreePixmap( fgDisplay.Display, window->Window.Pixmap );
+        }
     }
+    else
+    {
+        /*
+         * XXX HINT: the masks should be updated when adding/removing callbacks.
+         * XXX       This might speed up message processing. Is that true?
+         * XXX
+         * XXX A: Not appreciably, but it WILL make it easier to debug.
+         * XXX    Try tracing old GLUT and try tracing freeglut.  Old GLUT
+         * XXX    turns off events that it doesn't need and is a whole lot
+         * XXX    more pleasant to trace.  (Hint: Think mouse-motion!)
+         * XXX
+         * XXX    It may make a difference in networked environments or on
+         * XXX    some very slow systems, but I think that that is secondary
+         * XXX    to making debugging easier.
+         */
+        winAttr.event_mask        =
+            StructureNotifyMask | SubstructureNotifyMask | ExposureMask |
+            ButtonPressMask | ButtonReleaseMask | KeyPressMask | KeyRelease |
+            VisibilityChangeMask | EnterWindowMask | LeaveWindowMask |
+            PointerMotionMask | ButtonMotionMask;
+        winAttr.background_pixmap = None;
+        winAttr.background_pixel  = 0;
+        winAttr.border_pixel      = 0;
 
-    window->Window.Handle = XCreateWindow(
-        fgDisplay.Display,
-        window->Parent == NULL ? fgDisplay.RootWindow :
-                                 window->Parent->Window.Handle,
-        x, y, w, h, 0,
-        window->Window.VisualInfo->depth, InputOutput,
-        window->Window.VisualInfo->visual, mask,
-        &winAttr
-    );
+        winAttr.colormap = XCreateColormap(
+            fgDisplay.Display, fgDisplay.RootWindow,
+            window->Window.VisualInfo->visual, AllocNone
+        );
 
+        mask = CWBackPixmap | CWBorderPixel | CWColormap | CWEventMask;
+
+        if ( window->IsMenu )
+        {
+            winAttr.override_redirect = True;
+            mask |= CWOverrideRedirect;
+        }
+
+        window->Window.Handle = XCreateWindow(
+            fgDisplay.Display,
+            window->Parent == NULL ? fgDisplay.RootWindow :
+                                     window->Parent->Window.Handle,
+            x, y, w, h, 0,
+            window->Window.VisualInfo->depth, InputOutput,
+            window->Window.VisualInfo->visual, mask,
+            &winAttr
+        );
+    }
     /*
      * The GLX context creation, possibly trying the direct context rendering
      *  or else use the current context if the user has so specified
      */
-    if ( window->IsMenu )
+    if( window->IsMenu )
     {
         /*
          * If there isn't already an OpenGL rendering context for menu
          * windows, make one
          */
-        if ( !fgStructure.MenuContext )
+        if( !fgStructure.MenuContext )
         {
             fgStructure.MenuContext =
-                (SFG_MenuContext *)malloc ( sizeof(SFG_MenuContext) );
+                (SFG_MenuContext *)malloc( sizeof(SFG_MenuContext) );
             fgStructure.MenuContext->VisualInfo = window->Window.VisualInfo;
             fgStructure.MenuContext->Context = glXCreateContext(
                 fgDisplay.Display, fgStructure.MenuContext->VisualInfo,
@@ -372,15 +401,15 @@ void fgOpenWindow( SFG_Window* window, const char* title,
             NULL, fgState.ForceDirectContext | fgState.TryDirectContext
         );
     }
-    else if ( fgState.UseCurrentContext )
+    else if( fgState.UseCurrentContext )
     {
-      window->Window.Context = glXGetCurrentContext();
+        window->Window.Context = glXGetCurrentContext( );
 
-      if ( ! window->Window.Context )
-        window->Window.Context = glXCreateContext(
-            fgDisplay.Display, window->Window.VisualInfo,
-            NULL, fgState.ForceDirectContext | fgState.TryDirectContext
-        );
+        if( ! window->Window.Context )
+            window->Window.Context = glXCreateContext(
+                fgDisplay.Display, window->Window.VisualInfo,
+                NULL, fgState.ForceDirectContext | fgState.TryDirectContext
+            );
     }
     else
         window->Window.Context = glXCreateContext(
@@ -426,27 +455,31 @@ void fgOpenWindow( SFG_Window* window, const char* title,
 
     wmHints.flags = StateHint;
     wmHints.initial_state = fgState.ForceIconic ? IconicState : NormalState;
+    if( GL_FALSE == window->State.IsOffscreen )
+    {
+        /*
+         * Prepare the window and iconified window names...
+         */
+        XStringListToTextProperty( (char **) &title, 1, &textProperty );
 
-    /*
-     * Prepare the window and iconified window names...
-     */
-    XStringListToTextProperty( (char **) &title, 1, &textProperty );
-
-    XSetWMProperties(
-        fgDisplay.Display,
-        window->Window.Handle,
-        &textProperty,
-        &textProperty,
-        0,
-        0,
-        &sizeHints,
-        &wmHints,
-        NULL
-    );
-    XSetWMProtocols( fgDisplay.Display, window->Window.Handle,
-                     &fgDisplay.DeleteWindow, 1 );
-    XMapWindow( fgDisplay.Display, window->Window.Handle );
-
+        XSetWMProperties(
+            fgDisplay.Display,
+            window->Window.Handle,
+            &textProperty,
+            &textProperty,
+            0,
+            0,
+            &sizeHints,
+            &wmHints,
+            NULL
+        );
+    
+        XSetWMProtocols( fgDisplay.Display, window->Window.Handle,
+                         &fgDisplay.DeleteWindow, 1 );
+    
+        XMapWindow( fgDisplay.Display, window->Window.Handle );
+    }
+    
 #elif TARGET_HOST_WIN32
 
     WNDCLASS wc;
@@ -552,7 +585,13 @@ void fgCloseWindow( SFG_Window* window )
 #if TARGET_HOST_UNIX_X11
 
     glXDestroyContext( fgDisplay.Display, window->Window.Context );
-    XDestroyWindow( fgDisplay.Display, window->Window.Handle );
+    if( GL_FALSE == window->State.IsOffscreen )
+        XDestroyWindow( fgDisplay.Display, window->Window.Handle );
+    else
+    {
+        glXDestroyGLXPixmap( fgDisplay.Display, window->Window.Handle );
+        XFreePixmap( fgDisplay.Display, window->Window.Pixmap );
+    }
     XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
 
 #elif TARGET_HOST_WIN32
@@ -671,17 +710,19 @@ void FGAPIENTRY glutShowWindow( void )
     freeglut_assert_ready;
     freeglut_assert_window;
 
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    XMapWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
-    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
+        XMapWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
+        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
 
 #elif TARGET_HOST_WIN32
 
-    ShowWindow( fgStructure.Window->Window.Handle, SW_SHOW );
+        ShowWindow( fgStructure.Window->Window.Handle, SW_SHOW );
 
 #endif
-
+    }
     fgStructure.Window->State.Redisplay = GL_TRUE;
 }
 
@@ -693,21 +734,25 @@ void FGAPIENTRY glutHideWindow( void )
     freeglut_assert_ready;
     freeglut_assert_window;
 
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    if( fgStructure.Window->Parent == NULL )
-        XWithdrawWindow( fgDisplay.Display, fgStructure.Window->Window.Handle,
-                         fgDisplay.Screen );
-    else
-        XUnmapWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
-    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
+        if( fgStructure.Window->Parent == NULL )
+            XWithdrawWindow( fgDisplay.Display,
+                             fgStructure.Window->Window.Handle,
+                             fgDisplay.Screen );
+        else
+            XUnmapWindow( fgDisplay.Display,
+                          fgStructure.Window->Window.Handle );
+        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
 
 #elif TARGET_HOST_WIN32
 
-    ShowWindow( fgStructure.Window->Window.Handle, SW_HIDE );
+        ShowWindow( fgStructure.Window->Window.Handle, SW_HIDE );
 
 #endif
-
+    }
     fgStructure.Window->State.Redisplay = GL_FALSE;
 }
 
@@ -720,19 +765,20 @@ void FGAPIENTRY glutIconifyWindow( void )
     freeglut_assert_window;
 
     fgStructure.Window->State.Visible   = GL_FALSE;
-
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    XIconifyWindow( fgDisplay.Display, fgStructure.Window->Window.Handle,
-                    fgDisplay.Screen );
-    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
+        XIconifyWindow( fgDisplay.Display, fgStructure.Window->Window.Handle,
+                        fgDisplay.Screen );
+        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
 
 #elif TARGET_HOST_WIN32
 
-    ShowWindow( fgStructure.Window->Window.Handle, SW_MINIMIZE );
+        ShowWindow( fgStructure.Window->Window.Handle, SW_MINIMIZE );
 
 #endif
-
+    }
     fgStructure.Window->State.Redisplay = GL_FALSE;
 }
 
@@ -743,12 +789,11 @@ void FGAPIENTRY glutSetWindowTitle( const char* title )
 {
     freeglut_assert_ready;
     freeglut_assert_window;
-    if( fgStructure.Window->Parent != NULL )
-        return;
-
+    if( ! fgStructure.Window->Parent &&
+        ( GL_FALSE == fgStructure.Window->State.IsOffscreen ) )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    {
         XTextProperty text;
         
         text.value = (unsigned char *) title;
@@ -763,14 +808,13 @@ void FGAPIENTRY glutSetWindowTitle( const char* title )
         );
         
         XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
-    }
 
 #elif TARGET_HOST_WIN32
 
-    SetWindowText( fgStructure.Window->Window.Handle, title );
+        SetWindowText( fgStructure.Window->Window.Handle, title );
 
 #endif
-
+    }
 }
 
 /*
@@ -781,12 +825,11 @@ void FGAPIENTRY glutSetIconTitle( const char* title )
     freeglut_assert_ready;
     freeglut_assert_window;
 
-    if( fgStructure.Window->Parent != NULL )
-        return;
-
+    if( ! fgStructure.Window->Parent &&
+        GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    {
         XTextProperty text;
         
         text.value = (unsigned char *) title;
@@ -801,14 +844,13 @@ void FGAPIENTRY glutSetIconTitle( const char* title )
         );
 
         XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
-    }
 
 #elif TARGET_HOST_WIN32
 
-    SetWindowText( fgStructure.Window->Window.Handle, title );
+        SetWindowText( fgStructure.Window->Window.Handle, title );
 
 #endif
-
+    }
 }
 
 /*
@@ -819,9 +861,13 @@ void FGAPIENTRY glutReshapeWindow( int width, int height )
     freeglut_assert_ready;
     freeglut_assert_window;
 
-    fgStructure.Window->State.NeedToResize = GL_TRUE;
-    fgStructure.Window->State.Width  = width ;
-    fgStructure.Window->State.Height = height;
+    /* XXX Could delete/create/set-window-id for offscreen. */
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
+        fgStructure.Window->State.NeedToResize = GL_TRUE;
+        fgStructure.Window->State.Width  = width ;
+        fgStructure.Window->State.Height = height;
+    }
 }
 
 /*
@@ -832,14 +878,16 @@ void FGAPIENTRY glutPositionWindow( int x, int y )
     freeglut_assert_ready;
     freeglut_assert_window;
 
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    XMoveWindow( fgDisplay.Display, fgStructure.Window->Window.Handle, x, y );
-    XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
+        XMoveWindow( fgDisplay.Display, fgStructure.Window->Window.Handle,
+                     x, y );
+        XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
 
 #elif TARGET_HOST_WIN32
 
-    {
         RECT winRect;
         
         GetWindowRect( fgStructure.Window->Window.Handle, &winRect );
@@ -851,10 +899,9 @@ void FGAPIENTRY glutPositionWindow( int x, int y )
             winRect.bottom - winRect.top,
             TRUE
         );
-    }
 
 #endif
-
+    }
 }
 
 /*
@@ -865,21 +912,23 @@ void FGAPIENTRY glutPushWindow( void )
     freeglut_assert_ready;
     freeglut_assert_window;
 
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    XLowerWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
+        XLowerWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
 
 #elif TARGET_HOST_WIN32
 
-    SetWindowPos(
-        fgStructure.Window->Window.Handle,
-        HWND_BOTTOM,
-        0, 0, 0, 0,
-        SWP_NOSIZE | SWP_NOMOVE
-    );
+        SetWindowPos(
+            fgStructure.Window->Window.Handle,
+            HWND_BOTTOM,
+            0, 0, 0, 0,
+            SWP_NOSIZE | SWP_NOMOVE
+        );
 
 #endif
-
+    }
 }
 
 /*
@@ -890,21 +939,23 @@ void FGAPIENTRY glutPopWindow( void )
     freeglut_assert_ready;
     freeglut_assert_window;
 
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
+    {
 #if TARGET_HOST_UNIX_X11
 
-    XRaiseWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
+        XRaiseWindow( fgDisplay.Display, fgStructure.Window->Window.Handle );
 
 #elif TARGET_HOST_WIN32
 
-    SetWindowPos(
-        fgStructure.Window->Window.Handle,
-        HWND_TOP,
-        0, 0, 0, 0,
-        SWP_NOSIZE | SWP_NOMOVE
-    );
+        SetWindowPos(
+            fgStructure.Window->Window.Handle,
+            HWND_TOP,
+            0, 0, 0, 0,
+            SWP_NOSIZE | SWP_NOMOVE
+        );
 
 #endif
-
+    }
 }
 
 /*
@@ -915,8 +966,9 @@ void FGAPIENTRY glutFullScreen( void )
     freeglut_assert_ready;
     freeglut_assert_window;
 
-#if TARGET_HOST_UNIX_X11
+    if( GL_FALSE == fgStructure.Window->State.IsOffscreen )
     {
+#if TARGET_HOST_UNIX_X11
         int x, y;
         Window w;
 
@@ -946,9 +998,7 @@ void FGAPIENTRY glutFullScreen( void )
             );
             XFlush( fgDisplay.Display ); /* XXX Shouldn't need this */
         }
-    }
 #elif TARGET_HOST_WIN32
-    {
         RECT rect;
 
         /* For fullscreen mode, force the top-left corner to 0,0
@@ -980,8 +1030,8 @@ void FGAPIENTRY glutFullScreen( void )
                       SWP_NOACTIVATE | SWP_NOOWNERZORDER | SWP_NOSENDCHANGING |
                       SWP_NOZORDER
                     );
-    }
 #endif
+    }
 }
 
 /*
@@ -994,7 +1044,7 @@ void* FGAPIENTRY glutGetWindowData( void )
 
 void FGAPIENTRY glutSetWindowData(void* data)
 {
-    fgStructure.Window->UserData=data;
+    fgStructure.Window->UserData = data;
 }
 
 /*** END OF FILE ***/