Typed.js
Typed.js is a library that types. Enter in any string, and watch it type at the speed you've set, backspace what it's typed, and begin a new sentence for however many strings you've set.
You may like
nice-waves is a Vanilla JS library that makes creating waves a breeze.
GSAP is an industry standard JavaScript animation library from GreenSock that lets you craft high-performance animations that work in every major browser.
Javascript animation engine.
The official website for mojs.
Velocity.js: An incredibly fast animation engine for motion designers.
The JavaScript animation engine of the future.