C compilers

SunPlus released sources for the C compiler. It doesn't include the assembler and is based on gcc2 so quite hard to compile: https://github.com/vsmile-dev/unsp-gcc

uN'SP IDE is the official IDE for the CPU used. It can still be downloaded from GeneralPlus website (for example in the GPL951 section) - local copy

Assemblers

XASM is the original assembler provided by the uN'SP IDE

Naken assembler has support for uN'SP and provides a standard include file for SPG200 registers.

Work in progress patch to add uN'SP support in vasm. There are problems in vasm handling the pure 16-bit CPU, I have asked the vasm developers for help solving that.

This early homebrew experiment took an interesting approach of not using an assembler at all.

Emulators

MAME has good support for the V.Smile.

Unununium is a standalone emulator, but is known to have some bugs.

Häftig is a work in progress emulator.