Game Engine Analysis

The source engine developed by the Valve Corporation is most notably associated with the games Counter Strike: Source, Half-Life 2, Team Fortress 2, and the Portal series. The Source engine is known for the ability to render HDR lighting setups and an advanced facial animation, and lipsync editor. As far licensing the source engine, the exact cost is shrouded by an non-disclosure agreement, in order to use the engine you'd have to contact Valve personally. To get a feel for the engine however you can purchase Garry's Mod on Steam for about 10 bucks, which is basically a watered down Source Dev Kit.

Compared to other engines, Source is primarily built for FPS games, and there it shines especially in the context of multiplayer and co-op; both the Counter-Strike and Left 4 Dead series are evidence of this. While the graphic capabilities of the engine are definitely strong, I wouldn't say that graphics are the main selling point. It's the ability to play smoothly online with friends, facilitated by the Steam interface of course. The Source engine is highly optimized for high latency situations, with accurate projectile prediction capabilities even when working on unstable networks.

As far as audio capabilities the Source engine supports 2D, 3D and 5.1 stereo surround sound with pre-rendered Doppler effects. Supported API's include FMOD and OpenAL. The source engine also includes it's own audio editor called Vaudio for scripting ambient loops and trigger events.