rndgen is a Java application that mirrors the functionality available from Leon's Random Generators. They use a database of words and sentence forms to create various kinds of random text, including band names, song lyrics, jokes, advice, and essays. They are whimsical and mostly nonsense. You definitely need a particular sense of humor to appreciate them.
These games are recreations of simple ASCII graphics games originally written in BASIC. They are ideal for use as Perl programming tutorials. Some of the first few games are PerlBlaster (defend your planet from invading aliens), PerlRacer (steer your car through the twisting passages), and PerlArena (eliminate the mutant hordes).
GEMpire is a simple turn based multiplayer strategy game, written in java, designed to be played over the internet in client-server fashion. It is a generalization of the commercial game Empire Deluxe for the PC. It consists mainly of a server, a client, a map editor, and a random map generator.
TuxKart is a 3D GoKart racing game with several famous OpenSource mascots participating. The game uses PLIB and OpenGL, and is portable to a wide range of OS's. There are several racecourses provided, with full information on how to add your own. Except for a few minor details, this game is essentially complete, and very playable.