Sentry is a realtime error logging and aggregation platform
Async utilities for node and the browser
Promise based HTTP client for the browser and node.js
An alternative to Underscore.js, delivering consistency, customization, performance, and extra features.
The de-facto solution to flexible routing with nested views
Ajax with less suck - (and node.js HTTP client to match)
browser-side require() the node.js way
Dynamic, browser-based visualization library
Observable data. Reactive functions. Simple code.
Micro check library
Timeago is a jQuery plugin that makes it easy to support automatically updating fuzzy timestamps (e.g. "4 minutes ago").
Micro client-side router inspired by the Express router (~1200 bytes)