Mods Online is a news and community forum, with a very active user base.

My Aperture Labs: Welcome to the Aperture Science Enrichment Center’s Online Community Networking Web Service (or ASECOCNWS for short). Here at the ASECOCNWS, test subjects may attempt to solve Portal puzzles, build their own Portal puzzle environments, or simply talk about cake.

OzSource is the home of the Australian Gaming Combine. Steam discussion, Community Portal, Gaming news and opinions, critiques, retrospectives. Oz Source has been resurrected from its Half Life 2 Deathmatch origins.

Planet Half-Life is the daddy of them all. It’s been online longer than most and is generally updated daily.

Play Stuff is a Social, Creative Lounge, for Geeks and Gamers.

Podcast 17 is a weekly verbal tour of the Half-Life community. It covers everything related to the Half-Life universe and features lively, informative recordings.

Portal: Prelude, as its name states, is an unofficial prequel to the game Portal. Its story revolves around the pre-GlaDOS epoch, even before she was plugged in.

SLUM is Czech Steam community and fan portal about Steam and Valve games.

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.

Steam Friends covers all the news related to Steam and Valve.

Steam Community and News Portal

SteamPowered is the home of Steam, a digital distribution platform. The website offers visitors the ability to buy and download games, interactive with other Steam users.