http://www.planethalf-life.com/swarm A mod in which humans fight against xen-creatures.

http://www.counter-strike.net The best HL mod after Team Fortress Classic.

http://counter-strike.notrix.net An unofficial counter-strike site.

http://i.am/unbc_cs A counter-strike site with many skins and other additional things for the mod.

http://www.sierrastudios.com/games/teamfortress The Team Fortress 2 site.

http://www.planetfortress.com/tf2 An unofficial TF2 site with lots of pictures , videos and more.

http://skins.counter-strike.net/skinshack Skins for counter-strike.

http://www.blackmesa.eon.dk/xenonexus/index.html Single player maps with scenarios for Half-Life so you'll never get bored playing alone...

http://www.counter-strike.deThe german site of the famous mod.It's being updated more regular than the usual one.

http://mod.thegamers.net/mods/hl.shtmlThis site contains maybe every half-life mod there is!!!

http://www.planethalflife.comThe total Half-life site.Contains EVERYTHING that concerns HL.You MUST visit it!!!

http://3dmr.gamedesign.net/reviews/opfor/Single player maps for my favourite game:Opposing Force.Unfortunately there aren't many maps for the time being.

http://www.planethalflife.com/mankeThis specific site belongs to Neil Manke , the best single-player maps' designer.One of his greatest creatings is "They Hunger".