Seriously one of the best online webgame communities [1] I have ever been a part of. Full of mods [2] and sporting it's own competitive league [3], tagpro is in active development and is close to being fully open source [4].

It's capture the flag in it's essence, with deep strategy enhanced by individual skill. Once you "get it," you'll be hooked.

[1] http://tagpro.reddit.com

[2] http://www.reddit.com/r/TagPro/wiki/index#wiki_modding_the_g...

[3] http://www.reddit.com/r/TagPro/wiki/mltp

[4] http://www.reddit.com/r/TagPro/comments/1mfjo3/community_inv...