As far as I understand it, that distinction doesn't really make sense with Wayland. The display server / compositor is also the "window manager". Client applic

As far as I understand it, that distinction doesn't really make sense with Wayland. The display server / compositor is also the "window manager". Client applications have their own buffer they draw on, and they negotiate the details of its handling with the compositor which manages the composition of all client buffers (and other data, such as input events) to form the final result. I suppose it's technically possible to write a protocol that involves a third client process (a "window manager") to draw something around another client's buffer and tell the compositor how to position things, but that sounds like a nightmare to synchronize.