script.aculo.us : script.aculo.us provides you with
easy-to-use, cross-browser user
interface JavaScript libraries to make
your web sites and web applications fly.
Band.js : An interface for the Web Audio API that supports rhythms, multiple instruments, repeating sections, and complex time signatures.
Scrollama : Scrollama is a modern & lightweight JavaScript library for scrollytelling using IntersectionObserver in favor of scroll events. The goal of this libra...
TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
base2 is a lightweight library that irons out all the annoying differences in JavaScript implementations. It provides the additional functionality from JavaScript 1.6+ that only Mozilla browsers implement.