draw.io is an online diagramming web site that delivers the source in this project.
draw.io uses the mxGraph library as the base of the stack, with the GraphEditor example from mxGraph as the base of the application part. The mxGraph library build used is stored under /etc/mxgraph/mxClient.js.
draw.io is dual licensed under either the GPL v3 or the mxGraph Commerical License. To use the commercial license, you must license from JGraph for payment.
A development guide is being started on the Github project wiki. There is a draw.io tag on Stack Overflow currently, please make sure any questions adhere to their guidelines for question.
The mxGraph documentation provides a lot of the docs for the bottom part of the stack. There is an mxgraph tag on SO.
The simplest way to run draw.io initially is to fork this project, publish the master branch to Github pages and the pages sites will have the full editor functionality (sans the integrations).
draw.io supports IE 9+, Chrome 30+, Firefox 31+, Safari versions actively patched by Apple (6.2.x, 7.1.x, 8.0.x and 9.x at time of writing), Opera 20+, Native Android browser 5.x+, the default browser in the current and previous major iOS versions (e.g. 9.x and 8.x) and Edge 20+.