⏰ Day.js 2KB immutable date library alternative to Moment.js with the same modern API
Object.observe polyfill/shim trying to be compliant
A lightweight engine that allows you to hitch new capabilities to the browser (prollyfill).
A better way to use localStorage and sessionStorage
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.