yargs the modern, pirate-themed, successor to optimist.
fs-extra contains methods that aren't included in the vanilla Node.js fs package. Such as mkdir -p, cp -r, and rm -rf.
YAML 1.2 parser and serializer
Simple to use, blazing fast and thoroughly tested websocket client and server for Node.js
a little globber
Handlebars provides the power necessary to let you build semantic templates effectively with no frustration
Lodash modular utilities.
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.