Valve is a video game company founded in 1996 that develops games like Counter-Strike, Team Fortress 2, and the Half-Life and Portal series. It also operates Steam, the dominant PC gaming platform with over 70% market share. Valve does not disclose financials but was valued at $4 billion in 2011 and has grown rapidly through Steam's success and games like Dota 2 and CS:GO. While known for having no management structure, Valve continues to drive the PC gaming market forward with innovations in VR, the Source engine, and Steam Machines.