yargs the modern, pirate-themed, successor to optimist.
Higher-order functions and common patterns for asynchronous code
Parse, validate, manipulate, and display dates
A querystring parser that supports nesting and arrays, with a depth limit
Tiny millisecond conversion utility
fs-extra contains methods that aren't included in the vanilla Node.js fs package. Such as mkdir -p, cp -r, and rm -rf.
The semantic version parser used by npm.
A light-weight module that brings window.fetch to node.js