GnGeo vs NeoBox

GnGeo is a free NeoGeo emulator for Linux, with the project also describing possible support for other Unix systems. It runs NeoGeo ROM sets identified by their MAME names; the listed example starts Metal Slug with `gngeo mslug`. Command-line options include home, arcade, and unibios modes, as well as fullscreen display, scaling, interpolation, raster interrupts, blitters, and visual effects. Sound and joystick support, player controls, and hotkeys are configurable. Settings can be supplied on the command line or in user and per-game configuration files. The project describes graphical frontends with features such as game previews and configuration options. GnGeo requires SDL 1.2.x, libz, and a NeoGeo BIOS; NASM 0.98 is optional for i386 assembly optimization. Games must be ZIP files, while the BIOS must not be, and the default search location is `$prefix/share/gngeo/`. The README describes a source build using `./configure`, `make`, and `make install`. The repository lists no releases, and its licensing notes forbid commercial use of GnGeo as a whole because of included code and licensing.

NeoBox is a native macOS app with a built-in Geolith Neo Geo emulator; users provide their own ROMs and BIOS files. It accepts MAME-format ZIPs, scans ROM folders, organizes recognized games with bundled metadata, and watches folders for additions. The maker says metadata covers 158 games, including MVS and AES titles through KOF 2003. NeoBox provides timestamped save states, numbered slots, per-game memory cards, and F12 screenshots. Display options include an optional Metal-rendered CRT shader, Auto 4:3, and pixel-perfect integer scaling. Xbox, PlayStation, Switch Pro, and MFi controllers work over USB or Bluetooth, with keyboard input also available. Users can select external MAME instead of Geolith; the maker says the library, save states, and bindings carry over. NeoBox requires macOS 14 or later and is native for Apple Silicon. The Mac App Store listing describes it as signed and notarized. The NeoBox: Neo Geo Player plan costs $14.99 as a one-time purchase.