KMatrix3d is a nice 3D matrix OpenGL screen saver for KDE.
This version is based on the code by Thomas John.
IMPORTANT: Packagers wanted - please contact developer.
Currently I'm working on the V2 version of KMatrix3D which will contain following effects:
1) endless corridor section
2) matrix world transitions
3) matrix reloaded intro effects
4) extensive use of shaders
5) performace improvements