I recall PinMAME being a fork of MAME, the UI was identical and they borrowed a lot of cores like the 6809 and various common sound boards that video used, like the Williams Yamaha 2151 and Midway DCS AD2105 DSP.

For a while they tried to keep the manufacturers happy by not allowing modified ROMs to run, I got a special build from the developers to let me run anything I wanted. I think those restrictions do not exist anymore.