Thanks for the pointers.
Achieving the parallax seems to be easy enough, but combining it with all these aminations seems a bit more tricky. The animations are more complex than animate.css's approach of just animating when the component is displayed - you can play the animation in reverse by scrolling up rather than down.
I've seen the New York Times and BBC produces stories told in that parallax / animated type way and it's very effective. I'm guessing therefore that they use a standard parallax approach and them one or more animation libraries together; I was hoping there was one neat library that brought it all together but maybe that's asking for too much.