[deafbybeheading]

As a big fan of the GPL, ...I'm skeptical. I don't think Valve would benefit from keeping any potential modifications (or even plugins) secret, given that these would be far removed from its bread-and-butter.

A friend once suggested that outside of licensing pressure, maintainership is a huge driving force behind open-source contributions: you find something that does almost what you need, then you make the changes you require, and if you get these accepted upstream, they're maintained for you for free, pretty much forever. In many situations, that's far more important than any IP you're trying to conceal.

[FooBarWidget]

Because it's far easier for a manager to say "no" than to say "yes". By not releasing code, he's running less risk than by releasing code. There might be a chance that he missed something and violated copyright somewhere, accidentally leaked some company secret, or accidentally gave competitors an advantage. Saying "no" is the easier choice.

[nightpool]

In case you missed it, there aren't any managers at Valve... http://news.ycombinator.com/item?id=3871463 http://www.valvesoftware.com/company/Valve_Handbook_LowRes.p...