I'll go on the record and say that I don't think what you downloaded here is actually the Half-Life 2 source code.
Well, it took less than half a minute to compile, completely error-free. Although that may be a testament to the superb coding talents at Valve, it is but the first of many clues that cause me to question the validity of this file that you got "from some guy who knows this guy who used to be on IRC."
The associated "content files" are extremely small. 8K, as a matter of fact, for the "combine" level. I have emails longer than 8K. No, I'm not doubting the superb abilities of Valve's coders to create some incredible compression techniques, I'm just noting that the file is about as big as an animated forum icon. In fact, if you open it, it IS an animated forum icon. One of those dancing anime chicks with the independently-moving breasts. Things like this, you know, make me question the authenticity of the source code that you have. Which would fit, in its entirety, on a floppy disk.
I question some of the filenames. Although this IS a beta, I'm skeptical that Valve would actually compile their flagship product into a single executable named "u_r_gay.exe."
And finally, the executable that this source code creates would appear to be a Strawberry Shortcake screensaver.
These are subtle, subtle clues. But I think they add up to a meaningful conclusion.
Score: 8.13; Total Votes: 2584 as of 2009-12-09.