RetroArch is the backend that powers OpenEmu on OS X: http://openemu.org

It's also used by the RetroPie project for the Raspberry Pi, which has made my living room TV a lot more fun: http://blog.petrockblock.com/retropie/

Their official distro/platform/whatever is Lakka: http://www.lakka.tv

I've personally had a better experience with it than with RetroPie. Less configuration-fiddling. Had it on a Pi2, now an Asus Chromebox, great on both (better on the Chromebox—way more single-core horsepower, which is what counts).

It's actually unrelated to OpenEmu. They have their own cores some of which are based on RetroArch cores but they don't use RetroArch cores directly.

Today I learned! Thanks.