Maybe there's a big list I'm ignorant of but it's somewhat interesting that it doesn't happen more often. e.g. my favorite PC arena FPS as a teen was Tremulous;

Maybe there's a big list I'm ignorant of but it's somewhat interesting that it doesn't happen more often. e.g. my favorite PC arena FPS as a teen was Tremulous; it was originally a mod but after Quake 3's engine was released under the GPL they turned the mod into a standalone game with it. Totally free, too, but I bet it could have had some financial success if the store model was as popular and accessible back then. Natural Selection is a similar game that did enjoy commercial success... But for better or worse the GPL seems to increase the likelihood of free as in beer releases, too. Maybe any potential revenue sharing model is just too hard for a lot of projects to set up (or was back then) since the GPL also can attract a wide set of contributors.