Valve the company behind the games such as Half Life and Half Life 2 is located in Bellevue, Washington. They are a exciting and dynamic company well known for picking up mods as retail games and welcoming budding game designers to there head office for tours.

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Source

Source

Commercial licence

The Source engine is a 3D game engine developed by Valve Corporation. Its unique features include a large degree of modularity and flexibility, an artist-driven...

GoldSrc

GoldSrc

Commercial licence

This QuakeWorld-based engine powered some of the most critically acclaimed engine's of it's day, like Half-Life, Counter-Strike, Day of Defeat, and many...

Source²

Source²

Commercial licence

The announced next gen Source engine in the making. A set of Source 2 tools for building new environments will ship with Half-Life: Alyx, enabling any...