Simple to use, blazing fast and thoroughly tested websocket client and server for Node.js
Higher-order functions and common patterns for asynchronous code
Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.
A logger for just about everything.
YAML 1.2 parser and serializer
A querystring parser that supports nesting and arrays, with a depth limit
Handlebars provides the power necessary to let you build semantic templates effectively with no frustration
get colors in your node.js console
Redis client library