It's really worth looking into the recent project that transpiled the Lua VM into JavaScript, and which allows Lua to be used in the browser -- even to interact with the DOM. The size of the Lua VM in JS is under 200 kB, not much bigger than a large JavaScript library.
I've seen that. I need to learn Lua. I have a friend who uses it as the scripting layer on top of all his C work, and he says its the best setup he's ever tried.