>>5355253open source doesn't just mean the source code is released, it generally means it's under a licence that doesn't prevent further modification and distribution.
simply distributing source code along with the product under the same eula (which is what asperite does) doesn't mean it's open source in any way.
the difference between free/libre software and open source software is mostly philospohical. free software and open source licences are not substantially different.
the main issue with doom permissions is that the actual content of the game -- textures, levels, sounds, branding, etc -- is what they need permission for. not the game engine.
there are projects like freedoom etc that replace all the content in the game with a new free game with no restrictions, which in that case getting permission would be trivial.
