javacript

configuration

nconf

Hierarchical node.js configuration with files, environment variables, 
command-line arguments, and atomic object merging. 

logging

winston

a multi-transport async logging library 

framework

express

Sinatra inspired web development framework for node.js -- insanely fast, flexible, and simple

Data

mongoose.js

elegant mongodb object modeling for node.js

utilities

moment

Parse, validate, manipulate, and display dates in javascript.

underscore

Underscore.js is a utility-belt library for JavaScript that provides support for the usual functional suspects (each, map, reduce, filter...) without extending any core JavaScript objects.	

bcrypt

bcrypt for NodeJs	

documentation

smartcomments

SmartComments, It's a tool that allow you to create implicit comments from javascript source code. You can integrate it with javascript documentation generators like YUIDocs.

JSDoc 3

An inline API documentation processor for JavaScript. JSDoc 3 is intended to be an upgrade to JsDoc Toolkit (JSDoc 2).