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.