It would actually be really cool if games officially adopted this kind of engine-based model that we see in some of the examples, where the "engine" would be FOSS (meaning it can be ported, modded, improved, etc.), and the "game" that is sold is the compiled binary blob graphics, assets, scripts, etc.<p>In short, I guess it would basically be like selling RPG Maker games or DOOM wad's, but without the engine itself being proprietary.