CoffeScript had quite a bit of influence on JavaScript and TypeScript today (and/or really great timing w/ similar thinking). All of these were in early releases of CoffeeScript, and showed up in modern JavaScript years later:

* fat arrow functions

* classes

* template strings, multiline strings

* destructuring and ...rest values (splatting)

* elvis operator (foo?.bar?.baz - in TypeScript)

honorable mention

* list/iterator comprehensions (made some good progress in the ES speccing process, but ultimately didn't land)