nabla-linux

You could try to use the Win32 debug API in the same way like Linux UML by using ptrace. But it would probably still be much slower because of missing things like PTRACE_SYSCALL. More performant would be a noMMU variant of UML for Windows, supporting only PIE executables, similar to nabla-linux [1]. This is also quite similar to how mssql for Linux works NT kernel+Win32 in a single usermode process (single address space) [2]. Interestingly, mssql also uses memory protection keys to recover a bit of fault tolerance but last time I checked Win32 does not have an API for MPKs. [1] https://github.com/nabla-containers/nabla-linux [2] https://threedots.ovh/slides/Drawbridge.pdf

Have you tried compiling Linux as User Mode Linux with emscripten? I imagine something like this https://github.com/nabla-containers/nabla-linux would run on wasm, too?