Libretro is a simple but powerful development interface that allows for
the easy creation of emulators, games and multimedia applications that
can plug straight into any libretro-compatible frontend. This development
interface is open to others so that they can run these pluggable emulator
and game cores also in their own programs or devices.

SameBoy is an extremely accurate open source Nintendo Gameboy (DMG)
and Gameboy Color (CGB) emulator, written in portable C.

It features link cable emulation, and includes open source DMG and CGB
boot ROMs.

Homepage:
https://docs.libretro.com/library/sameboy/
