Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
While hope may be lost with Urban Terror HD, it seems the XreaL version of Enemy Territory is moving along nicely.
XreaL is an open-source game engine that Phoronix was the first to report on in April of 2009. The lead developer of XreaL claims it to be the most advanced open-source game engine. It's code is based upon the open-source id Tech 3 engine , but it's been rewritten to provide a pure GLSL (GL Shading Language) renderer, is written against the OpenGL ES 2.0 specification, emerging OpenGL 3.x support, a true 64-bit HDR rendering pipeline, shadow mapping, light interaction system, and many other visual features lacking from nearly all open-source game engines. XreaL is not up to the same level as say the Unigine engine, but it's graphics back in 2009 were great and on the same level -- if not better -- than Nexuiz, which could be considered the open-source game with the most compelling graphics capabilities.