@dGr8LookinSparky asked me to make a list of quake3 mods that have an active forum. So far I found:
iortcw: https://github.com/iortcw/iortcw (very active on github but I can’t find a website or forum for them. It is a single player game based on quake3 code).
Urban Terror: https://www.urbanterror.info (very active and has forum).
Spearmint: https://clover.moe/spearmint/ (forum can be found at: https://forum.clover.moe/ )
Exessive dawn: http://edawn-mod.org/ (check out latest improvements at http://edawn-mod.org/forum/viewtopic.php?f=5&t=7 )
CPMA: https://playmorepromode.com/ see youtube clip down on page for more info on features.
Quake3 Programming Discussion Forum: https://www.quake3world.com/forum/viewforum.php?f=16
Dead but maybe useful:
Quake3-fortress: some development tools can be found at: https://web.archive.org/web/20080509161711/http://www.q3f.com/devtools.html
OpenArena: http://openarena.ws/smfnews.php (been years since last release but forum still active: http://openarena.ws/board/index.php )
Dead and probably useless:
Freeze Tag: some quake3 mod which code can be found at: https://web.archive.org/web/20090410063054/http://freeze.planetquake.gamespy.com:80/ Might be used as a base for a trem mod.
Ps many more live and dead Quake3 based mods can be found at: https://www.moddb.com/games/quake-iii-arena/mods
I hope this you will find something useful at at least one of above so you don’t have to ‘re-invent the wheel’.
See you in game,