GtkGLArea is an OpenGL widget for the GTK+ GUI toolkit. Just as GTK+ is built on top of GDK, GtkGLArea is built on top of gdkgl, which is basically a wrapper around GLX functions. The widget itself is very similar to the GtkDrawinigArea widget; it adds only few extra functions. Lower-level gdkgl functions make it easy to render on any widget that has OpenGL-capable visuals. The ability to render to off-screen pixmaps is also supported.