Had a conversation with the great guy who writes the emulator ZEsarUX today and he gave permission for his emulator to be made into a core. Some of the convo:
“ME: Good emulator, if i can just ask, is it possible to package for retroarch to go along side of fuse?”“Cesar: Yes, I remember now, I heard about libretro.Go on if you want to add to libretro, thanks!”
Im not a programmer, but if someone wishs to convert it, then permission has been granted.