I have experience of embedding and modifying both QuickJS and Lua. QuickJS is not bad, but Lua is a lot easier and has fewer bugs. JavaScript is a very complicated language under the surface; I think very few people, if any, know and remember all its quirks.

Amazfit's Zepp OS uses quickjs to run 3rd party watchfaces and apps in their smartwatch

I was surprised to find out I'd been wearing javascript on my arm all this time

It sounds like you're saying quickjs is what you'd try if you wanted to embed a language, but you haven't tried embedding quickjs yet?

I think there’s a fork called quickjs-ng that’s actively maintained on GH. Should be able to use it as a lib maybe with some externing.

I’ve also had luck using it in a wasm runtime thanks to quickjs-emscripten. Good if you need sandboxing sans full process isolation.

Thank you for sharing your experience! Wasm provides full process isolation, doesn't it? Do you mean that QuickJS provides cheaper sandboxing than wasm?

I’m not sure if wasm would be considered full process isolation but it does provide software based sandboxing. I’m referring to running quickjs in wasm by compiling it with emscripten.

https://github.com/justjake/quickjs-emscripten

I see, thanks!

While QuickJS is nice, JavaScript as a language is much uglier and more complicated than Lua.