FCE Ultra X, typically shortened to FCEUX, is an emulator for the Nintendo Entertainment System and Famicom, as well as the Famicom Disk System (FDS). It is an amalgamation of several FCE Ultra forks, to bring the FCE Ultra branches to a halt due to the vast number and their differing features. Ironically, it has also been forked, though mostly to increase the amount of platforms it is on, such as a Gamecube and Wii and Progressbar 1 port known as FCEUGX.