TraceKit : Not all browsers support stack traces on error objects, but TraceKit squeezes out as much useful information as possible and normalizes it.
voxel.css : The goal of this project is to provide a lightweight 3D CSS library with very simple implementation.
Protovis : Protovis composes custom views of data with simple marks such as bars and dots. Unlike low-level graphics libraries that quickly become tedious for vi...
PeerJS : Peer-to-peer data in the web browser.
PeerJS completes WebRTC as an API abstraction, connection broker, and binary serialization format
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.
Modest Maps is a small, extensible, and free library for designers and developers who want to use interactive maps in their own projects.