XWayland isn't a normal Wayland client - it requires special assistance from the compositor. In particular, the compositor acts as the X window manager and ther

XWayland isn't a normal Wayland client - it requires special assistance from the compositor. In particular, the compositor acts as the X window manager and there's a special interface between it and XWayland on the Wayland side to make everything work. I don't think it's possible to even implement something like XWayland as an ordinary Wayland client. By design, ordinary Wayland windows are not permitted to know or control their on-screen position, and X relies heavily on apps being able to do both. This is also a major reason why Wine will never support Wayland in the same way that it does X. Basically, if your preferred compositor ever gets fed up of maintaining support for running X applications, the only way you'll be able to run apps that haven't been ported to Wayland is in an emulated desktop confined to its own window. Expect this to happen sooner rather than later given the current attitudes to backwards compatibility. (Think about Ubuntu dropping support for 32-bit applications, for example.) On the positive side, at least Windows 10 doesn't suffer from the same limitation...