I don't know what kind of use case you have in mind specifically, but wherever you would use a scripting engine, you can embed a small Wasm runtime instead and

I don't know what kind of use case you have in mind specifically, but wherever you would use a scripting engine, you can embed a small Wasm runtime instead and let your end-users pick their favorite* language (*) as long as there is a toolchain that supports using it on Wasm :P