Valve, creators of best-selling game franchises (such as Counter-Strike, Dota 2, Half-Life, Left 4 Dead, Portal, and Team Fortress) and leading technologies (such as Steam and Source), today launched user-defined  "Tagging" of products on Steam, a leading platform for games and software with over 75 million accounts worldwide. Now available in beta, Tagging gives Steam customers the ability to... more.