I am not sure if there is prior art for X11 proper, but there is at least one Wayland compositor built on top of the Godot engine that can run X programs throug

I am not sure if there is prior art for X11 proper, but there is at least one Wayland compositor built on top of the Godot engine that can run X programs through XWayland: https://github.com/SimulaVR/Simula https://github.com/SimulaVR/Simula And yes, with a bit of hacking you can do silly things like put physics on the windows and shoot holes in them. It won't get you close to what is in that Unity demo though. That would require re-designing all the apps. In my experience it's a massive pain in the ass to get eye-candy like that working correctly for arbitrary UIs and it's not worth the effort for most apps.