Platforma - Wireframe library of layouts and UI elements
ExpressJS - Sinatra inspired web development framework for node.js -- insanely fast, flexible, and simple
Contra Wireframe Kit - Open source wireframe kit for design and prototyping 🚀
Famous Engine - The Famous Engine is a free and open source JavaScript rendering engine.
Source Wireframe Kit - Library of 537 blocks for desktop and mobile prototyping
Chart.js - Easy, object oriented client side graphs for designers and developers.