Before the Switch came around, the Wii U was the all-in-one Nintendo machine that every homebrew enthusiasts could have wished for. It could run Wii U and Wii games natively, and with the virtual Wii environment (also known as vWii) running in its hardware, which was basically full Wii hardware backwards compatibility, it allowed for everything that ran previously on the Wii to also run on the Wii U almost by default.
The Wii U also offered new emulation options when it came to Virtual Console, adding DS and a new N64 emulator, both of which offered new options for Virtual Console injections, making the Wii U the best option to emulate everything from Nintendo's catalogue from the NES, all the way up to the Wii, including SNES, Game Boy, GBC, GBA, DS, Nintendo 64 and even Gamecube through Nintendont on vWii, making the only missing Nintendo system on the Wii U at this point in time the 3DS, with everything else being playable on it.
However, the Wii U came and went, and a lot of users felt like the homebrew community and its developments towards Wii U-specific applications was lacking, specially compared to that of the Wii's overwhelming homebrew scene. Most of the Wii U usage when it comes to homebrew was backpedaling on Wii-specific applications, with very few apps being actual native Wii U software that made use of the additional hardware power that the U had compared to the Wii's.
Eventually, the Wii U ended up getting RetroArch alongside a wide variety of cores to go with it, but with recent developments in the Wii U scene, RetroArch had been left behind to make use of the most recent and developed CFW for the device, this one being the Aroma custom firmware by @Maschell , which allows running homebrew applications as apps directly shown in the Home Menu, alongside a lot of other features.
Since then, RetroArch was stuck to run in the older development version of Aroma, titled "Tiramisu", that didn't have the current features of Aroma, and doesn't provide RetroArch with the same functionality of running it as an app in the Home Menu. Originally, builds for Aroma already existed, but these builds had the huge drawback of taking minutes to boot even a single game, and each time a new game or core was booted up, the same occurred, with the user having to wait minutes to be able to launch just one game.
This is all starting to change as of recent weeks in Aroma's own source code, thanks to the steady development by devoted Wii U users and hackers like @QuarkTheAwesome, @ploggy, @Maschell, @Vague Rant and others, RetroArch now has early alpha builds of RetroArch and some of its cores with Aroma compatibility, which have started to show up in RetroArch's own Github issue regarding Aroma compatibility According to some research, it seems like recent changes in the Aroma code for beta 17 regarding the Wii U's own CafeOS' FAT32 filesystem driver, and some optimizations to improve 'readdir' and 'stat' have been a key part in making the current RetroArch build for Aroma load assets and cores at a much faster speed compared to before.
According to @QuarkTheAwesome, their most recent work regarding RetroArch for Aroma covers the following:
Not only that, but progress on RetroArch's PSX core titled "PCSX Rearmed" has also been getting developments specifically for the Wii U to make use of threaded rendering, threaded compiler, fast mutexes, AX audio driver and an unai GPU driver, all of these to bring PlayStation games to a playable and decent framerate on the Wii U. This is yet another potential core that could be added into a more recent and updated RetroArch version for the Wii U, once full Aroma compatibility is ironed out.
While the Wii U certainly doesn't have much prominence nowadays in homebrew communities, it's always good to see older consoles still getting some love way past their prime, more so for consoles like the Wii U that had so much of its back catalogue (and overall) potential left to waste.
Just to reiterate, this builds of RetroArch for Aroma are in no way an official release, and they're essentially just alpha/testing versions for debugging plausible issues that might arise.
The developers involved in Wii U hacking are working on the WUHB version of RetroArch, so be sure to follow GamerParadise's own RetroArch Wii U thread to keep a close eye on any updates regarding RA through Aroma.
Source GameParadise's RetroArch Wii U Discussion Thread
