You have probably already done the GtkRadiant/installation or at least found out what GtkRadiant is, otherwise you would not have found this book, but, to tell it again, its a Level Design program also known as mapping program, with it, you make and design maps to play in all games based on the id Tech 3 engine. Technically, GtkRadiant will create .map files, which then are compiled by the compiler Q3Map2. You have probably already downloaded a few maps, and are now interested in making some maps yourself, if this is the case, then this is a good place to learn. If you already have mapped for some time, but want to learn a bit more, this will be a good place to learn, after I have written some more stuff.
Game packs exist for the following games. Generally, this includes support for all expansions and modifications as well.
- Doom 3- A Windows-only variant called D3Radiant (based on Q3Radiant, not GtkRadiant) is integrated into Doom 3. GtkRadiant 1.5.x can be used to make Doom 3 maps in Linux, by utilizing Doom 3's integrated map compiler in conjunction.
 - Quake
 - Quake II
 - Quake III Arena
 - Quake 4- Being based on the id tech 4 engine, it also uses a version of D3Radiant internally. However, GtkRadiant 1.5 can still be used to create maps on Linux.
 - Return To Castle Wolfenstein
 - Wolfenstein: Enemy Territory
 - Half-Life
 - Heretic II
 - Soldier of Fortune II: Double Helix
 - Star Trek: Voyager Elite Force
 - Star Wars Jedi Knight II: Jedi Outcast
 - Star Wars Jedi Knight: Jedi Academy
 - Medal of Honor: Allied Assault
 - Call of Duty
 - Call of Duty 2
 - Nexuiz
 - Xonotic
 - Tremulous
 - War§ow
 - Prey
 - Darkplaces
 - UFO: Alien Invasion
 
In addition, the following games and projects use GtkRadiant as a map editor, by using the GtkRadiant Quake III Arena game pack and an external map compiler or converter:
- Neverball
 - Crystal Space game engine
 - Irrlicht Engine (supports Q3A .bsp files)
 - Blob Wars : Blob And Conquer (custom game pack)