Mednafen is a portable, utilizing OpenGL and SDL, argument(command-line)-driven multi-system emulator with many advanced features. The Atari Lynx, GameBoy (Color), GameBoy Advance, NES, PC Engine(TurboGrafx 16), SuperGrafx, Neo Geo Pocket (Color), PC-FX, and WonderSwan (Color) are emulated. Mednafen 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 at the press of a button, and are saved in the popular PNG file format.
Mednafen is distributed under the terms of the GNU GPL.
Due to the threaded model of emulation used in Mednafen, and limitations of SDL, a joystick is preferred over a keyboard to play games, as the joystick will have slightly less latency, although the latency differences may not be perceptible to most people.