GnGeo

Overview

Games launch by ROM-set name, such as mslug for Metal Slug. GnGeo supports AES emulation, save states, and home, arcade, and unibios modes.

Setup requires SDL 1.2.x, libz, and a NeoGeo BIOS. Game files must be ZIP archives; the BIOS must be uncompressed. GnGeo searches under $prefix/share/gngeo/ by default. The documented source build runs ./configure, make, and make install; NASM 0.98 is optional for i386 assembly optimization. The repository has no releases, so users should be prepared for a source-oriented installation.

Key features

Display, audio, and controls

Fullscreen, resolution scaling, interpolation, raster interrupts, and selectable blitters and effects offer substantial control over presentation. Sound and sample-rate options, joystick support, per-player control settings, and configurable hotkeys cover common tuning needs. These options reward users who want to adjust behavior, but make GnGeo less suitable for someone seeking a polished, minimal-setup experience.

Emulation choices and frontends

GnGeo can use Cyclone, Starscream, or Gen68k for its 68k core, and DrZ80, Raze, or MAME Z80 for its Z80 core; defaults depend on the target. The README also describes GGF, XGngeo, and gngeogui frontends, including game previews and configuration options. Those frontends can provide a more visual route through the emulator, while the command line remains the direct option for users who prefer explicit control.

Pricing

GnGeo is free and open source. Its sole plan, GnGeo, costs 0.00 USD per free; there is no free trial because no paid tier is described. The price does not remove the setup requirements: users still need the listed libraries and BIOS, and the README says commercial use of GnGeo as a whole is forbidden because of included code and licensing.

Platforms

GnGeo targets Linux, with the project also describing possible support for other Unix systems. Linux is the platform to choose it for; broader Unix support should not be treated as a given. Its SDL 1.2.x dependency and source-build workflow also make it a less straightforward fit than software distributed as a ready-to-run release.

Who it's for

GnGeo is a sensible choice for Linux users who want NeoGeo emulation with selectable CPU cores, configurable display and controls, save states, and per-game settings. It is less appropriate for people who want a turnkey install, do not have the required BIOS, or need to use the emulator commercially.

Pros and cons

• Pros: Broad display, sound, and control settings let users tailor the emulation rather than accept a fixed setup.
• Pros: Per-game configuration, selectable CPU cores, and frontend options give technically confident users several ways to manage their library.
• Cons: SDL 1.2.x, libz, a separate BIOS, and a source build make installation more involved than a ready-to-run package.
• Cons: The stated commercial-use restriction rules it out for commercial deployments.
• Cons: No repository releases means users should not expect a published release download there.

Alternatives

For other options, browse Neo Geo Emulators.

• Virtual Jaguar is a free emulator for Android, iOS, Linux, macOS, the web, and Windows; choose it if that platform range matters and you can use a libretro frontend such as RetroArch.
• NeoCD/SDL is free for Linux and Windows, but its non-commercial limits and requirement for an original NeoGeo CD BIOS make it a better fit only when those terms and its CD focus suit your needs.
• NeoDS is free to use for non-commercial purposes; consider it if that licensing scope fits your use.
• NeoRAGEx is a free Windows emulator with games and BIOS not included; choose it if Windows is your target.
• Geolith is a free option for Linux, macOS, and Windows.
• NeoCD/PS2 is free software, with its BIOS not provided.
• Lynx.emu is a paid, open-source Android app at 2.99 USD per once, with ROMs supplied by the user; it is for Lynx emulation rather than NeoGeo.
• GxGeo is another free option.

Verdict

Choose GnGeo if you want configurable NeoGeo emulation on Linux and are willing to handle its dependencies, BIOS, and source build. Its adjustable emulation and per-game configuration are the main reasons to favor it; the commercial-use restriction and installation burden are the clearest reasons to look elsewhere.