Mirror Hall is an experimental app that aims to turn any Linux device into a
second monitor.

It is designed on both desktop and mobile devices, and supports both
hardware-accelerated and software-based encoding to stream video efficiently.

Mirror Hall makes use of a new, experimental GNOME feature to create virtual
monitors, and requires UDP traffic to be allowed by the network and firewall.
Support for other desktops will be added once a standardized API exists.