emmd vs Genesis Plus GX

emmd is a free Sega Genesis (Mega Drive) emulator written in Go and targeting Model 1 hardware. Its desktop library can scan ROMs and organize games with artwork and metadata. It includes save-state management, rewind, fast-forward, shader effects, RetroAchievements integration and configurable settings. The emulator supports Motorola 68000 and Zilog Z80 CPUs, VDP rendering, YM2612 FM synthesis and SN76489 PSG audio. It handles two-player three-button and six-button controllers, battery-backed SRAM, and save states checked with CRC32 checksums and ROM CRC matching. NTSC and PAL can be detected from a ROM header or selected manually. A LibRetro core is available for compatible frontends, and a documented macOS build creates an application bundle with an icon and code signing. The stated scope is officially licensed, released Genesis games; unlicensed or homebrew games, prototypes, beta ROMs and non-controller peripherals are unsupported. Platforms listed are Windows, macOS, Linux and iOS. Building requires Go 1.25 or later, and the repository identifies the license as GPL-3.0.

Genesis Plus GX is a free, open-source emulator for Sega's 8-bit and 16-bit systems, including SG-1000, Mark-III, Master System, Game Gear, Genesis/Mega Drive, and Sega/Mega CD. It supports backward-compatibility modes and describes its CPU, video, and sound emulation as highly accurate, with cycle-accurate CPU and sound synchronization. The emulator reads raw and interleaved ROMs, as well as CUE+BIN, ISO+WAV, and ISO+OGG CD images. Emulated peripherals include 2-, 3-, and 6-button pads, multitaps, the Sega Mouse, and light guns; supported cartridge hardware includes SVP DSP, EEPROMs, Game Genie, Action Replay, and Lock-On. Standalone builds are available for GameCube and Wii, and the project lists access through frontends such as RetroArch, BizHawk, and OpenEmu. It describes compatibility with released software for its supported systems, while noting that it cannot test every game from start to finish. Some Master System games depend on particular hardware or VDP modes. The multi-platform core source is under a non-commercial license.