What language is it? Is the language just specific to that ide or can other language be changed to work with this ide?
It's no secret that I really like Clojure and as a lisp,
it was the easiest language for me to start the prototype
with, but there's no reason this couldn't be done for any
language with a dynamic runtime. The rest is mostly simple
analysis of an AST and some clever inference. So could
Light Table have used JS instead? Certainly - and
hopefully it will get there sooner rather than later.