This is a thought-experiment app based around the idea of having a terminal emulator running in a separate container from the session inside of it, with the kernel as the only intermediary.

This is accomplished by means of file descriptor passing of the pseudo-terminal device from a small "agent" program running on the other side of a container boundary. The agent is started using the usual container tools (flatpak-spawn, toolbox, podman), but creating a session is done purely via sockets.

Boxi uses different application identifiers when it is run for different containers. This allows creating individual launcher icons for each container.