emmd vs Nostalgist.js

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.

Nostalgist.js has no write-up on Specifiction yet; its figures are above.