Valve Corporation is a developer, publisher, and digital distributor based in the United States. It owns and operates the biggest PC digital distribution platform, Steam. The company was founded in 1996 by Gabe Newell and Mike Harrington. The company developed and published such titles and series as Half-Life, Counter-Strike, Dota, Left 4 Dead, Portal, Day of Defeat and others. Valve has designed and manufactures such hardware as HTC Vive and Valve Index virtual reality headsets.