That particular codebase isn't going to help you much- Gabe and Co. re-wrote portions of the Source engine subsequent to that leak. Moreover, I can assure you that if they figure out whom is the guilty party on making a "version" of Half Life exist on Pandora without their permission, you can expect that they're going to ruin much, much more than your day.
lulzfish said:
They're closed-source.
But I'll give you 20 bucks if you can get us the code to any one of those unobfuscated