Steam is a content delivery, digital rights management, multiplayer and communications service and platform developed by Valve Corporation for digital entertainment. It is currently used to digitally distribute and manage games including Half-Life, Half-Life 2 and Counter-Strike: Source.
Steam also replaces WON, the original authentication framework for Half-Life multiplayer games and a number of other now largely or entirely defunct titles.
Steam offers more than games, content downloadable from Steam includes popular tools like Half Life Model Viewer and Hammer World Editor, a map editting tool.
Steam has over eleven million active accounts and that number is constantly growing, with new user accounts being created daily.