Chart.js is an easy, object oriented client side graphs for designers and developers. You can visualise your data in 6 different ways. Each of them animated, fully customizable and look great, even on retina displays. Chart.js uses the HTML5 canvas element. It supports all modern browsers, and polyfills provide support for IE7/8.
Chart.js is dependency free, lightweight (4.5k when minified and gzipped) and offers loads of customization options. it is licensed under MIT License.