The HTML5 Shiv : The HTML5 Shiv enables use of HTML5 sectioning elements in legacy Internet Explorer and provides basic HTML5 styling for Internet Explorer 6-9, Safari...
store.js : localStorage wrapper for all browsers without using cookies or flash. Uses localStorage, globalStorage, and userData behavior under the hood.
Leaflet : A Modern, Lightweight Open-Source JavaScript Library for Interactive Maps
Sammy is a tiny javascript framework built on top of jQuery, It's RESTful Evented Javascript.