r571 / 28-09-2014
Gambatte is a portable, open-source Game Boy Color emulator. Its accuracy is among the highest and is based off numerous reverse engineering tests and documented studies. It is currently available as both a core for RetroArch, as well as an individual emulator. That said, it's not actively developed anymore.
Windows: Doesn't mention minimum
Linux: Doesn't mention minimum
Mac: OS X+