The monochrome desktop (ST High resoltion)
and the graphical user interface of Hatari.
"The Pawn" - a game that uses ST-low and ST-medium resolution at the
same time.
The "Do-Things" demo running on Hatari running on Aranym running on
Linux... confusing...
Hatari running DOpE/DROPS, a real-time operating system that is developped at
the university of Dresden.