Because raw directory indexes are fragile and often taken down, the community has moved to:
Download parent ROMs first, then clones. Keep the neogeo.zip or other BIOS files in the same roms/ folder. index of mame roms
Let’s get one thing straight: MAME is 100% legal. The emulator itself is open-source and freely distributed. However, ROMs (the game data) are copyrighted software. Because raw directory indexes are fragile and often
You are legally allowed to download a MAME ROM only if: Most "index of mame roms" directories are operating
Most "index of mame roms" directories are operating without copyright permission. Hosting or downloading from them may violate laws in your jurisdiction. That said, many copyright holders tolerate emulation of "abandonware" (games no longer commercially available), but "abandoned" is not a legal status.
MAME releases a new version every month. Each version updates ROM sets (fixing dumps, adding new games, renaming files). Collectors want complete "full sets" (e.g., mame0245_full.zip set) matching a specific MAME version. Indices often host these massive archives (over 80GB compressed).