People who are interested in DOS software might take note of "Pits", a DOS assembler demo from 2024 which features, quote:
- Multithreading (using all hyper-threads / CPU cores)
- Video mode up to Full HD (1920x1080 / 16 bpp)
- 64-iterative ray-casting
- Pure DOS with Protected Mode (no drivers, no DPMI)
It is a seriously technically impressive demo, if not being the most visually impressive.