UXN

About this profile

Detail	Value
Type	libretro
Classification	Community fork
Source	https://codeberg.org/iyzsong/uxn-libretro
Upstream	https://github.com/chmod222/zuxn
Version	0.0.2, stated in build.zig.zon
Revision	iyzsong/uxn-libretro@2037b34ee0bf
Profiled	2026-03-25
Profile	YAML, JSON
Cores	uxn

Technical notes

Libretro wrapper around the zuxn library (Zig implementation of the Uxn/Varvara spec by Hundred Rabbits). The file device in Varvara handles ROM-initiated I/O but does not load system files from the system directory.

No BIOS or firmware files required.

Why no files

Uxn/Varvara is a software-defined stack machine with 64KB of memory. The VM has no firmware or BIOS. ROMs compiled from Uxntal assembly are loaded directly via libretro game_info. The .info declares no firmware.

Next steps

• Get your files, for the setup you play on
• Every system, and the files each one needs
• When a game does not start

Data as of 4 November 2026.