RGraph

RGraph is an HTML5 software library for charting written in native JavaScript. It was created in 2008. RGraph started as an easy-to-use commercial tool based on HTML5 canvas only. It's currently freely available to use under the open-source GPL license and supports more than 50 chart types in both SVG and canvas.

License
RGraph is dual licensed using the Open Source GPLv2 and commercial.

Mentions
In July 2014, Salesforce made RGraph available to be plugged into the reporting and dashboard tools on its mobile platform. RGraph is among six third-party visualization tools available inside the dashboards, together with Google Charts, D3.js, CanvasJS, Chart.js, and Highcharts.

In a book "Android Cookbook: Problems and Solutions for Android Developers," RGraph is recommended as an alternative to creating Android charts in pure Java.