squeak/pharo
Corman Lisp/Clozure CL/SBCL Common Lisp Interface Manager https://github.com/robert-strandh/McCLIM
meta emu: b-em/atomulator/elkulator/rpcemuspoon/ep128/amstrad cpc/fuse/stella/atari800/hatari/vice/uae/apple II/kegs/basilisk/sheepshaver/vmac/psx/pcsx/mess/EACA Video Genie etc. A lot has compatible FLOSS ROMs included.
sky is the limit: Stellarium