Console messages for cool kids
Tired of adding prefix for each broswer when it comes to the new css3 attributes?
Tiny polyfill for the placeholder form element attribute. Requires Prototype.js.
Allows for automatic Image fallbacks for browsers that can't handle SVGs
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.