It would be nice if global templates had a scripting language that was truly multilingual. By this I mean that every keyword, comment, variable name, and method call could be localized.
The only programming languages I'm aware of with this property are Scratch, Blockly, and eToys. (See https://www.wired.com/story/coding-is-for-everyoneas-long-as-you-speak-english/ )
However, I believe we can make a variant of JavaScript which is fully multilingual, and use this to write Scribunto modules (T61101).