GtkGLExt is an OpenGL extension to GTK 2.0 or later. GtkGLExt provides the GDK objects to support OpenGL rendering in GTK, and GtkWidget API add-ons to make GTK+ widgets OpenGL-capable. As opposed to Jane Loff's GtkGLArea, it does not provide any OpenGL widget, but an interface to use OpenGL on *ANY* GTK+ widget.