Wayvara is a Wayland Varvara emulator running in exaequOS. It is able to run graphical Uxn apps (rom files) that are written in Uxntal and compiled with uxnasm (included in exaequOS as well).
Uxn (https://wiki.xxiivv.com/site/uxn.html) is a stacked-based virtual machine created by Hundredrabbits.