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

Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.

Chart.js - Easy, object oriented client side graphs for designers and developers.

Square - Square helps millions of sellers run their business-from secure credit card processing to point of sale solutions. Get paid faster with Square. Sign up today!

Famous Engine - The Famous Engine is a free and open source JavaScript rendering engine.

Taptalk - Personal video and photo messaging