A better way to use localStorage and sessionStorage
A tool to show and add tags to images
A behavior for Internet Explorer allowing it to recognize and render various CSS3 box decoration properties
Tiny polyfill for the placeholder form element attribute. Requires Prototype.js.
CSS4 parent selector based on jQuery
Small, fast, awesome. The only ES5-ish set of polyfills (shims) you can mix-and-match because they're individual AMD modules.