GnGeo vs NeoCD-Libretro

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.

NeoCD-Libretro has no write-up on Specifiction yet; its figures are above.