Please See Below!
They are either derivatives, extensions or add-ons which complement or can outright improve the overall experience. These builds are very often created by independent developers whom simply want to bring more greatness to an already excellent emulator.
An unofficial build of MESS from 2009 made by one of MAME's active developers. It uses a fixed game list and works better for certains games such as Zelda's Adventure.
Please check MAME's change log section to find out..!
Nothing additional to provide for this sub-section.