Valve Corporation (also known as
Valve Software, commonly referred to as
Valve) is an American
video game developer and
digital distribution company headquartered in
Bellevue,
Washington, United States. Its
Luxembourg-based business office subsidiary for
European regions,
Valve S.a.r.l., was opened in 2012. Founded in 1996 as
Valve L.L.C. by former
Microsoft employees
Gabe Newell and
Mike Harrington, the company has developed the critically acclaimed
Half-Life,
Counter-Strike,
Portal,
Day of Defeat,
Team Fortress,
Left 4 Dead video game series, alongside
Dota 2. It also developed and maintains
Source on which most of its games run, and the
software distribution platform Steam, which has led to the
Steam Machine, a line of pre-built gaming computers running
SteamOS.