Source engine

The Source engine is a game engine developed by Valve Software for their first-person shooter computer game Half-Life 2 and for licensing to other developers. It provides rendering, sound, user interface, networking, artificial intelligence, and physics.

The engine is expected to debut with Half-Life 2. Valve is also porting the original Half-Life and mods like Counter-Strike to the Source engine (appropriately titled Counter-Strike: Source).

Troika Games' Vampire: The Masquerade - Bloodlines was the first publically announced licensee of the Source engine. Valve later announced licensees including Arkane Studios (for Arx Fatalis 2) and Smiling Gator Productions (for Twilight War, an MMORPG) .