mxGraph is a fully client side JavaScript diagramming library. It is the underlying technology that powers the drawing functionality that you see in https://www.draw.io.
We started developing mxGraph in 2005 when Internet Explorer 6 and Firefox 1.5 were the latest browsers, thus we still support all browsers back this far for IE and FF, as well as most Opera, Chrome and Safari versions. mxGraph supports iOS and Android touch events.
mxGraph uses the vector drawing language native to the browser being used, VML for IE 8- and SVG for more modern browsers.
mxGraph uses no third-party software, it requires no plugins and can be integrated in virtually any framework. Also provided is server-side functionality in Java and .NET for persistence (open and save) functionality, as well as server-side image generation.
mxGraph is dual licensed. It is licensed under the non-commercial CC, http://creativecommons.org/licenses/by-nc-sa/3.0/, and the mxGraph license, http://www.jgraph.com/mxlicense.html. The mxGraph license is for commercial use, you can find the pricing at http://www.jgraph.com/purchase.html.
If you prefer to download a zip of the mxGraph package, you can obtain that from http://www.jgraph.com/download.html.
In the root folder there is an index.html file that contains links to all resources. You can view the documentation online on the Github pages branch, http://jgraph.github.com/mxgraph. The key resources are the JavaScript user manual, the JavaScript examples and the JavaScript API specificiation.
If you have a programming question relating to mxGraph, you can either use Stackoverflow, http://stackoverflow.com/questions/ask/?tags=mxgraph, or our own technical forum http://forum.jgraph.com. Be aware Stackoverflow is a general Q&A site, ensure you use the mxgraph tag, that you have read the posting FAQ and that you have a programming question.
If your question is not programming related, or what you have to say is not a question, use our Google+ community instead, https://plus.google.com/b/100634082864796769666/communities/103111053636844545203.
If your interest is commercial and you prefer to talk privately, contact us via the jgraph.com site, http://www.jgraph.com/contact.html.
If you have bug reports or feature requests, use the Github issue tracker, https://github.com/jgraph/mxgraph/issues.