I took a link to some text from someone at Valve a long while back. Sometime last year. It was either from here or PHL, I'm not for certain. Also, I should have said 'mostly original', the Havok engine slipped my mind.
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Almost forgot. Yes, it was said to be for HL2 and TF2. I believe I saw mention of CS2 being done on it also, but I'd have to dig up the article to be for certain.
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Go go Google.
http://www.shacknews.com/onearticle.x/7313/This comment was edited on Jan 4, 03:41.