Wow. Okay I did a search just because I am the curious type and nothing came up.
Anyone heard of or 'played' Sauerbraten? (http://www.sauerbraten.org)
I'll let you guys read it for yourselves but one of the 'big' features is being able to map in-game. And cooperatively.
I can assume, this being a forum all about maps (duh), it isn't very powerful, but still works for the basic quake 3 era (?) stuff, on mapping terms. Except with other engine gimmicks. Pretty decent for being open source too.
Oh and that lovely bloom. :ssj:
