RetroArch
RetroArch is a free and open-source, cross-platform frontend for emulators, game engines, video games, media players and other applications. It is the reference implementation of the libretro API, designed to be fast, lightweight, portable and without dependencies. It is licensed under the GNU GPLv3. RetroArch runs programs converted into dynamic libraries called libretro cores, using several user interfaces such as command-line interface, a few graphical user interfaces optimized for gamepads, several input, audio and video drivers, plus other sophisticated features like dynamic rate control, audio filters, multi-pass shaders, netplay, gameplay rewinding, cheats, etc. RetroArch has been ported to many platforms.