[yannn]

Good point, I don't know how hard transitioning back would be, we would need to review the language diff. Is it simple stuff like removing type annotations and reverting "i += 1" (Luau) by "i = i + 1" (Lua) ?

I don't know if they have an interpreter only mode.

Yes, our projet runs on WebAssembly. (https://app.cu.bzh)

[implicit]

Luau also adds a continue keyword. It's probably the most troublesome thing you might encounter if you wanted to go from Luau back to Lua.