We have closed the loop.
The launcher can now assemble tal files on the fly, you can use Left to write #uxn programs, Nasu to make graphics, Dexe to include them into your projects.
That means you can have a complete workstation on a NDS, GBA, Playdate, etc..
Thanks to everyone who helped to put this together.
@celeste It's a little vm, I have a couple of notes on it here: https://wiki.xxiivv.com/site/uxn.html
Lemme know if you have any questions.
@celeste pico-8 is a fantasy console, it's a program made to look like a an old console.
Uxn is a virtual machine, so it runs everything through a little virtual cpu with 32 instructions. Porting uxn for example is only a matter of porting the emulator, porting pico-8 means porting a lua compiler.
@neauoire
I obviously understand the difference between PICO-8 and Uxn (particularly in intent) but porting a Lua interpreter is not significantly harder than porting Uxn, it's pure ANSI C and is meant to be ultra-portable just like Uxn. It'd be the rest of the large internals of PICO-8 that'd be difficult to port (especially since it's proprietary and impossible for anyone to port themselves :P)
Devine Lu Linvega
Cel 
nytpu the wyvern