http://www.stud.uni-karlsruhe.de/~unk6/transluxent/"TransluXent is an implementation of an X Server which uses OpenGL for what would be the graphics card driver. As such it can easily offer translucent windows."
It will proabably be finished before Microsoft's own effort is done in Longhorn (due out in 2004-5)
This is great! Finally, alpha-blended windows and shadows!
