nodeunit - Easy unit testing in node.js and the browser, based on the assert module.
sharedb - A database frontend for concurrent editing systems
react-waypoint - A React component to execute a function whenever you scroll to an element.
dnode - turtles all the way down rpc
next.io - No more hells. Callbacks made easy, with error handlers and more.
Telescope - An open-source social news app built with Meteor
yarr - Yet Another React Router inspired by the Express router (~1200 bytes)