I'll publish the source shortly as part of a post-jam writeup, but (spoilers) yes I'm going to try adding languages. It would really only involve getting different "die" configurations and changing out the dictionary (or starting to use some more elaborate words API).
I'm in the process of putting together my post-mortem article (which will be up at my blog when I'm done), but the short answer is "I used cl-notebook and parenscript". The first is a notebook-style editor for Common Lisp (for which I'm in the process of writing an `itch.io` exporter), and the second is a library that provides a CL->JS transformation for an extended subset of the language.
