Prototype : Easy Ajax and DOM manipulation for dynamic web applications
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
JavascriptOO : Every javascript project you should be looking into.
With examples, categories, install commands, CDN links, project and author stats, and more.
EnhanceJS : EnhanceJS is a new Javascript framework designed to improve the application of Progressive Enhancement by first testing browser capabilities for key J...
store.js : localStorage wrapper for all browsers without using cookies or flash. Uses localStorage, globalStorage, and userData behavior under the hood.
Modest Maps is a small, extensible, and free library for designers and developers who want to use interactive maps in their own projects.