I was stumbling due to lack of things to do a moment ago, and I got directed to the GoG Freespace 2 catalog entry.
Now, normally, I'd just say "Screw it" and keep clicking, but a though popped up before I did.
Went something like this:
"Wait...what the fuck? The source code for Freespace 2 is public. How can you sell a free game?"
It's gonna bug me now. Anyway, thoughts?