[sondr3]

I think they are more at the opposite side of the spectrum, languages like Flow, CoffeeScript and TypeScript are more akin to supersets of JavaScript (with potentially "simpler" syntax). Languages like ReScript and PureScript come from the functional world that as a feature compile to JS, but where the type system are sound without any of the baggage from JS and features that are (at least as of now) not available in JS like pattern matching. They are not an evolution of JS like Flow or CoffeeScript, but are rather for developers who want something more than just "JavaScript with types".