The newly released HBL uses libnx-compiled apps ONLY (at the moment). Well, to get RetroArch running on the Switch HBL, we would need to have all of the already compiled libtransistor RetroArch cores ported/compiled with the libnx library. If anyone skilled enough in coding wants to tackle this: FCEUMM has a Switch target, this could be used as a base example to begin porting from LibTransistor to LibNX: https://github.com/libretro/libretro-fceumm/blob/master/Makefile.libretro#L265 LibNX source code: https://github.com/switchbrew/libnx The best option here would be to have RetroArch to build its cores using both libtransistor and libnx for further compatibility down the road. LibNX has a huge thing on its favour right now, and that is JIT. With JIT, some of the slow cores that use more heavy resources than 2D consoles could see a major improvement in speed and performance. Since the 34c3 conference this December 28th, there have been two note-worthy homebrew releases, one being Snes9x 2010 and the other being a port of Doom '93. However, there seems to be something else in the works which has been quietly been commited to RetroArch's GitHub page. More cores have been compiled to work on the Switch, other than Snes9x 2010. Cores like FCEUMM, VBA Next and Virtual Jaguar are some of which are already working on the Switch, with more cores being worked on. You can watch videos of the cores compiled so far running on the Switch: Videos of RetroArch on the Nintendo Switch https://streamable.com/4yjz1 The commits all seem to use/be based in libtransistor, as well as some of the libnx libraries that team ReSwitched has released these past months. Cores currently available on the Switch: Snes9x 2010 (SNES) Snes9x (SNES) FCEUMM (NES) Virtual Jaguar (Jaguar) GearBoy (GB, GBC) VBA Next (GB, GBC, GBA) Picodrive (Genesis, MegaDrive, Master System, 32x, Sega CD) Handy (Atari Lynx) Yabause (Saturn) [Slow] FBA Alpha [Slow] Desmume (DS) [Slow] Also, Cheats are working for the RetroArch cores available as of January 14th, 2018. As of Jan 30th, 2018, @Daeken has begun work on a preliminary GPU library for the Switch: https://github.com/daeken/traNVparency This could boost the performance of certain cores (3D console cores most likely) For Gamecube/N64/PS2 cores, a GL driver or Vulkan driver is needed. An example: https://github.com/Rinnegatamante/vitaGL The official Switch's SDK might have Vulkan support in one way or another next to Nvidia's proprietary API, though it is not confirmed. A homebrew SDK with GL/Vulkan would be the best option to avoid proprietary (copyrighted) code.