DOM Monster Bookmarklet : DOM Monster is a cross-platform, cross-browser bookmarklet that will analyze the DOM & other features of the page you're on, and give you its bill of ...
Prototype : Easy Ajax and DOM manipulation for dynamic web applications
hunt : Library to detect when DOM elements become visible and disappear on scroll.
localForage : localForage is a handy library that improves the offline experience of your web app by using asynchronous storage (via IndexedDB or WebSQL where avail...
DOM Storage Query Language (DomSQL) is an SQL inspired interface for DOM Storage (or Web Storage as defined in the W3C working draft).