Hey everyone.
I'm working on a game and so far I'm inclined to use zDoom. I'm not sure if I'd actually be able to sell it though. I got the impression I could sell zDoom based games as long as the source code is included, but digging through the zDoom files I see things in there using the GNU license as well. Does anybody know anything about this? I'm guessing it's probably not allowed, in which case I'll just distribute the game for free.