emmd vs EmulatorJS

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.

EmulatorJS is a free, open-source frontend for RetroArch that lets a site owner embed an emulator in a web page. The project provides a code generator, and says the resulting embed can be added with a few lines of code. EmulatorJS uses RetroArch’s libretro cores to run games. Its supported systems documentation includes NES, Nintendo 64, PlayStation, PSP, Sega systems, and Commodore systems, though the project warns that this list may be out of date. Built-in options allow customization, and multiple languages are supported. The project describes EmulatorJS as a library or plugin rather than a standalone website, and it does not provide a Docker container. A public CDN offers paths labeled stable, latest, and nightly. The listed platforms are web, Android, iOS, and self-hosted. Pages must be served through a web server; opening an HTML file directly is unsupported. Threaded cores may improve performance, but need SharedArrayBuffer enabled through COOP and COEP response headers. The 4.3.0-pre release is marked as a prerelease and is discouraged for production use where stability is needed.