Valve Software is a video game developer made famous by its first product, Half-Life. Valve went on to create Team Fortress Classic (a mod for Half-Life) and several other extensions to Half-Life. They also took on-board the development of the highly popular Counter-Strike and Day of Defeat Half-Life mods. The company created a stir at E3 in May 2003 by debuting what appeared to be a surprisingly complete Half-Life 2. Valve is also still working on the long-awaited Team Fortress 2 standalone game.