Libretro is a simple but powerful development interface that allows for the
easy creation of emulators, games and multimedia applications that can plug
straight into any libretro-compatible frontend. This development interface is
open to others so that they can run these pluggable emulator and game cores
also in their own programs or devices.

Snes9x is a Super Nintendo Entertainment System / Super Famicom emulator.

This is a port of SNES9x 1.43 for libretro (it was previously called CAT SFC).
It is an ideal alternative to emulators with a more uncompromising approach to
accuracy, since it runs at full speed on low end devices, for example, low
power ARM SoCs.