Geolith vs NeoCDRX

Geolith is a free emulator for the Neo Geo AES, MVS, CD, and CDZ. It supports commercially released AES, MVS, and CD games, and runs on Linux, macOS, BSD, and Windows. Cartridge systems accept TerraOnion .NEO files; CD systems use .bin/.cue and can optionally use .chd images. BIOS files from a recent MAME set are required, with the needed archives varying by system. Geolith synchronizes its CPUs with the video and sound systems, though video event timing is best effort and cycle-accurate rendering remains a longer-term goal. Settings include system and BIOS mode, region, free play, memory card options, palette, and aspect ratio. Supported inputs range from Neo Geo joysticks to a Mahjong Controller, four-player extension board, V-Liner, and the Irritating Maze trackball. The project was written for The Jolly Good API and can be used in multi-emulator frameworks or standalone binaries. It does not support dedicated JAMMA PCB systems or PAL mode; an early Stakes Winner prototype is also unsupported because required data is missing.

NeoCDRX is a free homebrew emulator for Neo Geo CD and CDZ games on GameCube, Wii and Wii U through Virtual Wii. It supports region settings for USA, Europe and Japan, which provide different languages and can affect some game content. The listed processor cores are Z80 3.6 and M68000 3.3, and audio controls include a three-band equalizer for music and sound effects. Supported controllers include Wii Remote, Wii Remote Plus, Wii Remote with Nunchuk and GameCube controller. Media options include SD/SDHC, USB and DVD, plus GameCube options WKF and IDE-EXI V1. Virtual memory card saves can go to SD or USB, or to a physical GameCube memory card. Setup requires a Neo Geo CD/CDZ BIOS file named NeoCD.bin in NeoCDRX/bios. Each game goes in its own folder under NeoCDRX/games, with an mp3 subfolder for music. Wii and Wii U Virtual Wii installations are packaged for Homebrew Channel; using the Wii version requires a way to run unsigned code. The README describes the project as GPL open source, while GitHub lists LGPL-2.1.