Mednafen is a portable argument (command-line)-driven multi-system emulator. It has the ability to remap hotkey functions and virtual system inputs to a keyboard, a joystick, or both simultaneously. Save states are supported, as is real-time game rewinding. Screen snapshots may be taken, in the PNG file format, at the press of a button. Mednafen can record audiovisual movies in the QuickTime file format, with several different lossless codecs supported.

The following systems are supported: Atari Lynx, Neo Geo Pocket (Color), WonderSwan, GameBoy (Color), GameBoy Advance, Nintendo Entertainment System, Super Nintendo Entertainment System/Super Famicom, Virtual Boy, PC Engine/TurboGrafx 16 (CD), SuperGrafx, PC-FX, Sega Game Gear, Sega Genesis/Megadrive, Sega Master System, and Sony PlayStation.