General
 
Binary Arts
Fragged
id Software
PlanetGecko
PlanetQ3
PlanetQuake
Q3A Top 100
Q3Arena.com
Q3Arena.net
Quake III Arena
Quake3 Nation
Quake3World

Levels
 
FilePlanet
Vexar's Map Center
Vondur's War Supply
ztn's recycler

Level Reviews
 
..::LvL
M.O.B.S. Review Crew
QIC
The Big House

Skins
 
Super's Skin Site
UMUSTDIE

Editing
 
qeradiant.com
Quake3Mods
q-workshop3
RUST