D3.js - D3.js is a JavaScript library for manipulating documents based on data. D3 helps you bring data to life using HTML, SVG, and CSS.
Pixi.js - Fast lightweight 2D library that works across all devices
Chart.js - Easy, object oriented client side graphs for designers and developers.
Snap.svg - Snap.svg is a javascript SVG library for the modern web.
Chartist.js - Chartist.JS - simple responsive charts.
Raphael - Raphael.js is an Object Oriented drawing library. It is good at making in-depth diagrams with complex interactions.