distcc is a parallel build system that distributes compilation of C/C++/ObjC code across machines on a network. It can be set up in just a few minutes and makes builds up to ten times faster. It does not require machines to share a filesystem or have the same libraries or header files, and installation does not need superuser privileges.
libmng is the reference library for MNG, the animation extension to the popular PNG format. It provides powerful animation features combined with PNG's robustness and patent freedom.
pybliographer is a tool for managing bibliographic databases. It currently supports BibTeX files for reading and writing, and can also read Ovid files.
Wormz is graphical multiplayer game for many players (1 to 100, there can be 'bots' controlled by the computer). The basic principe is similar to the BSD game 'worm' - just stay alive longer than your opponents and you win.