Few links to interesting/useful sites related to defrag and/or quake3

General defrag site with a huge alive forum and many useful things on it, serverlist, pinboard, records overview etc.

ws.q3df.org

Map database for quake3 and mods, also has tutorials on mapping and skins

Russian site about defrag, competitions, other DF stuff

IRC:

#defrag        general df channel

#dfmap        df mapping channel

#bsh            bsh clan channel

#dStyle        ds clan channel

#sDF           sdf clan channel (openarena df mostly)