RetroArch version 1.5.0 has been released:
"RetroArch is the official reference frontend for the libretro API."
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.
RetroArch sets the standard on cross-platform portability right now.