Its interesting that on one hand, we have this shouting "embrace, extend, extinguish!" directed at TypeScript, and on the other, Facebook with Flow and Babel is

Its interesting that on one hand, we have this shouting "embrace, extend, extinguish!" directed at TypeScript, and on the other, Facebook with Flow and Babel is doing precisely that: its extending JS with their own type system, adding support for said type annotations to Babel (which is still thought of as the es.next -> es.current compiler) and still calling it JavaScript; or at least, muddying the waters (no extension change). Strangely, it appears to work. I've seen claims that Flow is better because "its just JavaScript, not another language" I don't get it.