DarkPlaces is a gameplay modification and a source port engine based on the computer game Quake. It adds enhanced network code, with asynchronous delta compression inspired by Tribes networking, a built in server browser, real-time lighting, and bump mapping, makes use of the OpenGL Shading Language and supports Ogg Vorbis. DarkPlaces is actively developed by Forest "LordHavoc" Hale and contributors. It is based on the Quake source code. Games that use DarkPlaces include Nexuiz, Transfusion, Xonotic and Nehahra (and by extension the machinima film The Seal of Nehahra).