XGL is an X server architecture layered on top of OpenGL. It is at an early stage in development and a number of important pieces are still missing. Xglx is the only server yet that use this architecture, it requires an already existing X server and is only intended for testing and development.
Because of a slow "development process", Novell decides to migrate the CVS of the Project and to make it private, paying developers to "speed up" the process.
The results are in these screenshots.
The next generation of Graphic Server on Linux? I hope it's true!