Zachary Slater: Can a GPL game engine be used on consoles like the Xbox 360 and Playstation 3?
Forest Hale: Not directly, however copyright holders have the right to provide other licenses on a case by case basis, in this case, id Software has a technology licensing program with reasonable prices, I am providing IllFonic with a license to my modifications and the modifications of many contributors (with whom I had to individually arrange licensing for this purpose over the years, and contributions I can not re-license I will have to remove or replace).
All my cards are on the table, as the DarkPlaces engine is developed in the open.
So IllFonic has a license from id Software for Quake engine on Sony Playstation 3 and Microsoft Xbox 360, and a license from me, which collectively allows them to use the DarkPlaces engine.
The GPL code and open assets for Nexuiz have forked under the new project name of Xonotic.