Editing

Bittoman's Lair
Download custom made maps for the Quake series.
http://www.angelfire.com/bc/bittoman/

BSP: Quake editor
Map editor and tutorial.
http://ourworld.compuserve.com/homepages/bernier/

BSP Headquarters
Home of the BSP Quake Editor
http://www.bspquakeeditor.com

Deathmatch maps
Contains custom deathmap maps.
http://www.angelfire.com/wy/oldquake/qmaps1.html

Geniacs Quake Map Played List
One line reviews of many Quake maps.
http://www.geniac.net/quake.htm

Gom Jabbar's Hideout
Includes downloads, map information and news.
http://www.gomjabbar.de/

QBrt's Quake Levels
Includes downloads and how to use them.
http://www.xs4all.nl/~brt/quake/index.html

Quake Editing Utilities
Various downloadable Quake utilities.
http://www.montefiore.ulg.ac.be/~quinet/games/QEU/

QuArK
Editor for games based on or similar to iD's series of Quake games. Supports 21 distinct games and their mods. Integrates a map editor, archive editors and texture management.
http://quark.planetquake.gamespy.com

Quark
Quake editor for Quake1, Quake2 and Hexen2: levels, QuakeC, maps, models, sounds.
http://www.planetquake.com/quark/

Quest
A 3d map editor for the series.
http://quest-ed.sourceforge.net/

Retinal's Broken Machine
Home of Quake and Q2 mapper Retinal, author of the Broken series.
http://retinal.fov120.com/

XL Repository
Includes downloads for Quake and Quake II.
http://www.modempool.com/pault