NOTE 09.11.2020 : Development on mxGraph has now stopped, this repo is effectively end of life.
The PHP model was deprecated after release 4.0.3 and the archive can be found here.
The unmaintained npm build is here
The mxGraph library uses no third-party software, it requires no plugins and can be integrated in virtually any framework (it's vanilla JS).
We created mxGraph in 2005 as a commercial project and it ran through to 2016 that way. Our USP was the support for non-SVG browsers, when that advantage expired we moved onto commercial activity around draw.io. mxGraph is pretty much feature complete, production tested in many large enterprises and stable for many years.
Over time you can expect this codebase will break features against new browser releases, it's not advised to start new projects against this codebase for that reason.