There is mame and mame32UI. Mame32UI is regular mame with a built in frontend that makes navigating games easy, but it is extremely ugly for an arcade cab. It is mostly for the casual gamer on a nondedicated computer.
Er,
Mame32 has been renamed to
MameUI for many reasons, the "break the camel's back" one probably being that 64 bit builds are officially being released for both mame and mameUI, making the "32" ending of the old name sound, well, old.
Of course the official reason
was to prevent confusion between official (CLI) mame 32 bit build, official (CLI) mame 64 bit build, win GUI mame (mameUI) 32 bit build, and win GUI mame (mameUI) 64 bit build. Now usually called (32 bit) mame, 64 bit mame, mameUI 32 bit, and mameUI 64 bit, respectively.
And since official mame has been 32 bit
for over six years, it's about time
mame32's name changed.
(Nothing against JohnIV or the rest of the mameUI team; it's very hard to change a commonly used name without a commonly accepted reason like 64 bit builds.)