Welcome to gnuboy, one of the fastest if not the fastest GB/GBC emu- lator available. gnuboy was written well over 20 years ago and achieved full speed on most machines of that era, on today's machines it runs close to 0% CPU usage. Unlike most modern GB emulators, gnuboy doesn't strive to be cycle-accurate (except where necessary), but to be fast, portable and compatible and to provide a good gaming experience.