GtkGLExt is an OpenGL extension to GTK+. It provides additional GDK objects which support OpenGL rendering in GTK+, and GtkWidget API add-ons to make GTK+ widgets OpenGL-capable.
Openmark will be a Open Source benchmark that will have 32/64 bit options for video rendering tests on X11 as well as HD speed, FSB, etc benchmarks. Also many tools like: temp monitor, speed control, etc.