EmulatorJS vs Mega-Pi

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NES, Nintendo 64, PlayStation, PSP, Sega systems, and Commodore systems, though the project warns that this list may be out of date.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.

Mega-Pi is a free, bare-metal Sega Mega Drive/Genesis emulator for Raspberry Pi hardware. It targets Raspberry Pi 3 and 4 and runs without an operating system such as Linux, which the project associates with near-instant boot and very low input latency. The emulator uses the Picodrive core and Circle bare-metal C++ framework, assigning orchestration, video, audio, and input work across four ARM cores. It scans .bin, .md, and .gen Genesis or Mega Drive files, plus Sega CD/Mega CD .cue files with .bin tracks and compressed .chd files. Sega CD emulation includes the Sub-CPU, PCM audio, CD audio, and rotation/scaling graphics hardware. Video uses 2× integer nearest-neighbor scaling to 640×480, with 44.1 kHz stereo through the Pi PWM sound engine. USB gamepads and keyboards are supported, and save states reside on the SD card. Running it requires a FAT32 card, boot files, a kernel image, game files, and USB input devices; Sega CD also needs regional BIOS files.