Open Quartz is a project to supply artwork to create a full game based around the Quake source code. The pak0 module contains content (maps, models, graphics and sounds) and Quake code which controls the behavior and rules of the game. There is also a playable version available that ships with the Darkplaces engine by LordHavoc. The final goal of Openquartz is to become a 100% replacement for the original Quake game data that runs in all the free Quake engines available at present.
Poopmup is a game, a sort of a shoot-em-up, but with a twist. As a child, you where tortured in the playground. You were a victim of the highschool hierarchy. You hacked hours on end, and built a machine that transformed you into a bird. You are now free (as in speech) to fly around the city and poop on passers-by.
Doom was the classic 3D shoot'em'up game from id Software. PrBoom is a game engine for playing Doom levels, which runs on both Windows and Linux/Unix systems. It uses the SDL graphics library. PrBoom a very faithful Doom port, with great effort taken to be compatible with as many original Doom levels and demos as possible.
ProQuake is a modification to the Quake source which is specifically intended for intense deathmatch play. It is a rock solid set of enhancements to unmodified NetQuake, such as precise aim, and other small, simple changes that improve the quality of netplay enormously. ProQuake is fully compatible with standard NetQuake and Clanring CRMod++ features including team scores, match timer, and client pings.