Cage is a kiosk compositor for Wayland. A kiosk is a window manager
(in the X11 world) or compositor (in the Wayland world) that is
designed for a user experience wherein user interaction and activities
outside the scope of the running application are prevented. That is, a
kiosk compositor displays a single maximized application at a time and
prevents the user from interacting with anything but this application.

WWW: https://www.hjdskes.nl/projects/cage/