kcat
Dosbox i586
The biggest hurdle will be finding a C++17 compiler that can target old OSs like that. As far as the codebase is concerned, there's generic fallbacks that don't rely on CPU-specific behavior, but it will depend on C++ standard features like atomics and threads being available.
I could also imagine performance being an issue, given slower CPUs that also lack SIMD extensions, but maybe it'll be fine if things are kept turned down (use few sources, avoid filters/effects and post-processing features, etc).
Maybe this? https://stackoverflow.com/questions/38243718/how-can-i-target-windows-98
I've used DSOAL back in the day (5 years) on an old crap blu brand Android using ExaGear. It was really great getting Diablo 2 to use EAX plus the hrtf stuff made the game really come alive. I'm specifically trying use on iOS now which has all kinds of CPU extensions (NEON especially). But now that i think of it that might not pass through dosbox-pure environment. But yes I was able to tweak the performance. I seen something about minGW compiler too.
