This is to be a "work-in-progress" directory of all Quake-related websites still in existence today as well as a memorial for the sites no longer with us. Hopefully this can help to bring all of the scattered communities together. I know I am missing many many websites please post all that you know here and I will continue to update this. Also, my memory is a little fuzzy so please feel free to correct any wrong information I have posted and I will update.
Generalhttp://planetquake.gamespy.com Planet Quake
http://www.quake3world.com Quake 3 World
Quake Videoshttp://www.own-age.com Own-age
http://www.quakeunity.com Quake Unity
http://premonition.dinodivine.com [PT] Tania's Premonition
Mapshttp://q3a.ath.cx Defrag Map Directory
http://lvlworld.com Quake 3 Map Directory
Defraghttp://www.breakdown-hq.com Home of Defrag and DF Competitions such as DFWC.
http://www.q3df.org MdD Server Records and the new "OPC" forums.
http://www.speedcapture.com Fastcap World Records
http://www.bedepa.de Berserker's Defrag Page
Clans/Teamshttp://teameventhorizon.com Team Event Horizon (Team-Based Tricking)
Q3 Toolshttp://q3mme.proboards.com/index.cgi Q3 Movie Maker's Edition
http://bpeers.com Q3A Shader Editor
http://www.qeradiant.com Radiant, Quake Level Editor
http://dev.alientrap.org/wiki/7 NetRadiant, User Updated Q3 Level Editor
http://shaderlab.com Q3Map2, compiler for Q3 Maps
Otherhttp://www.idsoftware.com iD Software, Gaming Company that created Quake
http://www.quakelive.com iD's new free browser-based Quake game based on Q3
Unsortedhttp://cggdev.orghttp://www.esreality.comTemporarily Offlinehttp://www.german-defrag.deR.I.Phttp://www.overdrivepc.com/forum The largest community forum in Q3 history.
http://www.ctf4.com AscendWand's site dedicated to ctf4
http://q3a.sytes.net First map database
http://www.mousepotato.org Old Server Records hosted by m00m1n
http://www.trickingq3.com Quake 3 Tricking Tutorials