The simplest thing I know of is the minimal Cage compositor for wayland, that only supports running a single fullscreen program: https://github.com/Hjdskes/cage

The simplest thing I know of is the minimal Cage compositor for wayland, that only supports running a single fullscreen program: https://github.com/Hjdskes/cage https://github.com/Hjdskes/cage With some hackery, you could probably build this as a backend for GTK/Qt that would run the server in the same process. But I don't know how useful that would really be.