The Neo Geo was a cartridge-based arcade system board and home video game console made by SNK in 1990. It was a unique console in that these two products both shared identical hardware, allowing for a truly "arcade-perfect" home console experience. The Neo Geo had an impressive lifespan of over 15 years, with games being developed and published beyond the company's buyout by Playmore.
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MAME has been able to run Neo Geo games for years and over the years, MAME became more accurate with the machine too. The default is the MVS version however it is possible to run the AES versions with some extra work (since MAME itself is like the Neo Geo as in that it can run arcade and console games too). It doesn't support the tile viewer.
Not as accurate as MAME and is no longer supported meaning that it might get harder to run on modern computers or finding ROMS. Still it has sprite ripping features and it is easier to boot up the AES version of a game too.