Retro shooters that still have a thriving or active online multiplayer community

[thetwaz]

Thinking about a recent comment I made about Unreal Tournament 99, which still has quite a lot of active and populated servers, what are your favourite retro shooters to play online, and do they still have an active online community? What mods or software do you need to play them?

For UT there is a fan made patch to download, but then it seems to pretty much work put of the original interface, which is cool.

Oldunreal's 469 Patch

 

[skramz]

q3 is stil pretty active last time i checked

 

[Ikagura Ikagura]

Xonotic and Cube 2 Sauerbraten are fairly active.