TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
Workbox : JavaScript Libraries for adding offline support to web apps.
JavascriptOO : Every javascript project you should be looking into.
With examples, categories, install commands, CDN links, project and author stats, and more.
Tracery : A story-grammar generation library for javascript. Write grammar objects, get generative stories.
jsPDF : A library to generate PDFs in client-side JavaScript.
Namespace.js is a small javascript script which provide namespacing utilities. It is framework independent. It also allows you to remotely include files.