Despite its age, MAME 0.84 is still widely searched for several reasons:
The reason 0.84 sets are so widely distributed on archive sites, torrents, and ROM repositories is because of the "abandonware" argument—a term that holds no legal weight. Capcom, SNK, Namco, and Nintendo still hold copyrights over these games. However, because these games are no longer sold in arcades (and many rights holders are defunct), enforcement is rare for non-commercial use. mame 0.84 romset