Is there's wayland server running as X11 client? Like XWayland but reversed.
Weston, the reference compositor for Wayland, has a special feature where instead of running it directly on hardware, you can also use it to run Wayland clients under X. At an X terminal, type
weston and press Enter.
From man 1 weston with my emphasis:
Weston has several backends as loadable modules: it can run on Linux KMS (kernel modesetting via DRM), as an X client, or inside another Wayland server instance.
Source: Jan Newmarch. "Running Wayland". Programming Wayland Clients, chapter 5. Found via Google Search for
wayland under x.
No, you don't type
westoffto close it.