DarkPlaces

DarkPlaces is a 3D game engine based on Quake, created by Forest Hale. It features many improvements over the original Quake engine, such as client-side QuakeC, limited support for the Quake 3 material shader system, decals, support for Quake 3 file formats, etc, while still remaining fully compatible to the original Quake assets and its QuakeC code. Hence why no major changes to the interface have been made. Darkplaces is licensed under the GNU General Public License.

Games
DarkPlaces is being used by the first-person shooter games Nexuiz, Open Quartz and Xonotic.