> Lua [is] the language with the best chance at making it into a browser engine
For better or for worse, I think there is pretty much 0 chance of Lua or for that matter Python showing up natively in browsers. There are too many technical and political things in the way.
But we already have good tools for compiling both of those languages into JavaScript. If for example the Python community made JavaScript a priority to compile to, we could make it run very well and integrate nicely with the browser environment.
For better or for worse, I think there is pretty much 0 chance of Lua or for that matter Python showing up natively in browsers. There are too many technical and political things in the way.
But we already have good tools for compiling both of those languages into JavaScript. If for example the Python community made JavaScript a priority to compile to, we could make it run very well and integrate nicely with the browser environment.