We just came across this a few days ago and evaluated its use for a new project. Instead for our needs we're moving forward with http://www.mindmup.com Certainly they're not directly comparable, as mindmup is a mindmapping tool, but depending what you're attempting to diagram and what your needs are, mindmup so far seems pretty awesome - all the front-end and back-end code is MIT licensed in github which was a huge plus.