GtkGLArea is an OpenGL widget for the GTK+ GUI toolkit.
Just as GTK+ is build on top of GDK, GtkGLArea is built on top of gdkgl which is basically wrapper around GLX functions. The widget itself is derived from GtkDrawinigArea widget and adds only few extra functions.
Lower level gdkgl functions make it easy to render on any widget that has OpenGL capable visual, rendering to off-screen pixmaps is also supported.
Related project which may iterest those who use GTK-- is GtkGLArea--. It is a C++ wrapper for gtkglarea written by Karl Nelson.
You need GTK+ and either OpenGL or Mesa, if you have both you can choose which one to use by giving --with-lib-GL or --with-lib-MesaGL option to configure.
Run './configure --help' to see all options you may give at configuration stage. Run './configure' and 'make' to build. You may now test programs in examples directory. Run 'make install' to install.
Include files go to PREFIX/include/gtkgl/
Library files go to PREFIX/lib/