OpenArena (version 0.8.8) is what happens when 2000s Linux users give Quake 3 the Freedoom treatment. The groundwork was already made quickly with Q3's source code being made in a surprisingly short timespan leading to the ioquake3 source port (for lack of a better word), so all that needed were a small handful of people that knew 3D modeling and texturing. It just ended up being that one of the more skilled art people was also horny for anime (monster-)girls. Good for them, I guess. Read some old chatter that a new iteration called "OA3" would shake up both the visual styling and character design, but maybe personal lives stalled that goal. Don't know everything.

Just how (in)compatible is this with the CPMA mod patch, though? There was also an oldish ioquake3 blog entry about raytracing, but that was also made during the time of Quake Wars, so functionality there is not as clear. Actually, take this second paragraph as an acknowledgement that I haven't taken part of a multiplayer server that wasn't automatically filled by an AI yet, so my information isn't as useful there. Wish I was more aware of the modding scene for OA/Q3 when activity was really ticking.

The game is quite literally off-market Quake III Arena, there's not much to say here.