Valve Corporation

Valve Corporation, also known as Valve Software, is an American video game developer, publisher, hardware, and digital distribution company headquartered in Bellevue, Washington. It is the developer of game franchises including Half-Life, Counter-Strike, Portal, Team Fortress, Left 4 Dead and Dota, the software service Steam, and hardware including the Steam Machine, Steam Deck and Valve Index.

Valve was founded in 1996 by former Microsoft employees Gabe Newell and Mike Harrington. Their debut game, the first-person shooter (FPS) Half-Life (1998), was a critical and commercial success that had a lasting influence on the genre. Harrington left in 2000. In 2003, Valve launched Steam, followed by Half-Life 2 (2004), the episodic sequels Half-Life 2: Episode One (2006) and Episode Two (2007), the puzzle games Portal (2007) and Portal 2 (2011), and the multiplayer games Team Fortress 2 (2007), Left 4 Dead (2008), and Dota 2 (2013).