MAME 2003-Plus is an evolved version of the classic MAME 0.78 codebase. While the original 0.78 set was frozen in time, the "Plus" version is a Libretro-maintained core
The is a specific, highly-regarded snapshot of arcade game ROMs corresponding to MAME version 0.78 (released around 2003–2004), often paired with the unofficial "MAME Plus!" derivative emulator. mame 078 plus romset