Rhai VS duckscript

For that world there is also Rhai (https://github.com/rhaiscript/rhai), TypeScript, Scheme, etc.

Though Moonbit does look nice too.

As far as I know there exists rhai scripting lang. You can check it out -> https://github.com/rhaiscript/rhai

Version 1.13.0 is released to crates.io.

Check out https://github.com/rhaiscript/rhai/blob/main/src/func/native.rs

The OS would be built in Rust and the module system could be made using ELF executibles (fast, but it could be really hard to implement modules to communicate with the kernel), WASM (can compile from many languages, slower but not too slow, APIs can be simple enough to implement if the correct VM is choses) or even a custom scripting language like rhai (slower, but best way for the implementation [way to connect modules and kernel]).

For sure, that's where something like rhai would shine: https://crates.io/crates/rhai

Currently i'm using it in cargo-make but will also use it later to parse args for duckscript commands.

At it's most basic you could make a really simple interpreter by just doing such a thing, and there is essentially already such a simple language like that built for/in rust called Duckscript (rust has a surprisingly large number of little embedded languages), and that would be completely and entirely sufficient for many purposes, though if you want speed then you'll need to JIT or AOT the code, which is why wasm is so handy as you can interpret or JIT (or even AOT it with wasmer) without the much larger overhead of a, for example, javascript or java embedded runtime.