Valve Community

L4D Maps is a website completely dedicated to Left 4 Dead and everything about it.

HL2 DM University’s mission statement is to promote and improve the online Half-Life 2 Deathmatch experience for all players by providing an extensive repository of useful and interesting information and files.

Gaming.Fi is a Finnish website covering plenty of games other than Valve’s games. It features plenty of updates and an active forum.

SteamCard is a simple way to display your stats from the Steam Community, just like a Live! Gamercard. SteamCards are just PNG images, which means you can embed them into forums, signatures etc. Different styles of SteamCard are avaliable so you can stand out from the crowd.

Stu-Pidaso is a website aimed at Half-Life and everything related to it.

HL Gaming covers all the news related to Valve gaming, including TF2, L4D and all your HL favourites.

Chain Studios is a Russian development studio, that creates mods for Half-Life

EviL’s Knights Clan is a Spanish language clan and community.

Steambans.com is a global banlist/watchlist made for the Steam technology from Valve. All bans that are accepted will enter a database which then is used to protect all servers under their supervision.

The L4D Map Database is a library of all Left 4 Dead maps (official and custom) in the form of a wiki that anyone can contribute to. Includes downloads, screenshots, videos, information, and more for each map.

Sven Co-Op is a co-operative mod for Half-Life 1. It allows players to play together to defeat the computer controlled enemies. It is possible to play through the original Half-Life game with friends and there are also hundreds of maps specifically designed for co-op play.

HL2World.com is a news and forum based site that has been around for a long time. The forum is particularly active.