Rhai VS embedded-scripting-languages

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

Hopefully the linked README provides a general overview (I know I need to write some more documentation!), but Steel is an implementation of the scheme programming language (not entirely compliant yet, but aiming for R5RS and R7RS compliance). It can be used as a standalone language via the interpreter/repl (like Python or Racket), or it can be embedded inside applications, like Lua. There are hundreds (thousands, probably) of embeddable languages, each with their own flavor - see a list compiled here for example https://github.com/dbohdan/embedded-scripting-languages

Use cases are generally for either configuration, scripting, or plugins - so scripting in games, or adding extensions to your text editor without having to use FFI or RPC + serializing a bunch of data. The advantage it has over using dynamic libraries (in general) is it runs in the same process, and can access the internal data structures directly without a lot of ceremony involved. The downside is typically is not as fast as native code unless a JIT is involved.

Javascript is an example of an embedded scripting, where the browser is the host application.

> There is a huge opportunity, IMO, for more players here.

There are quite a few embeddable scripting languages [1]. I think these days it's less common to embed a language mostly because there are good high-level languages that applications can be predominantly written in.

[1] https://github.com/dbohdan/embedded-scripting-languages

I'm not a huge fan of Lua but I think it is at least way more popular and better on every measure than TCL. There are plenty of other better less well-known options too: Rhai, Wren, AngelScript, Starlark (for some use cases), etc. There's a good list here.

or perhaps use one of this list (depending on who's writing the configuration): https://github.com/dbohdan/embedded-scripting-languages

https://github.com/dbohdan/embedded-scripting-languages (coincidentally, from a user whose name I recognize from the Tcl wiki)