Tidarque is an open source VRML browser for Unix. It intends to be robust, full-featured, flexible and fast (in that order !).
vuVolume is a framework for volume rendering algorithms in C++. When creating a new rendering method in vuVolume it is possible to just concentrate on the actual algorithm and let the framework take care of the more administrative tasks.
MusicWatcher is a perl based non-realtime music analysis and visualization system with complete example implementations. One example renders a 3d music driven animation in povray.
The Open Descent Foundation (ODF) is a community for developers, who want to help to create open source programs, tools, etc. for the famous games Descent1, -2 or -3. Everyone can join the ODF if he accepts the idea of writing open source programs.
PerlGo: the classic board game of Go, featuring a Pov-Ray rendered game board and animation capabilities as well as SGF-import and autoplay.
spyGLass is an OpenGL call tracer and debugger. It goes a step further than simply using ltrace because it knows what the arguments to the various gl* calls are, and it also knows about OpenGL's error flag.