this is a Cloud9 clone of : https://bitbucket.org/scriptoid/diagramo
running file 'web\editor\light-editor.html' works...
There are install instruction at :
Download files at : http://diagramo.com/download.php
Install instruction : https://github.com/paulwade/diagramo/blob/master/diagramo/INSTALL.txt
First hit on GitHub search of 'diagramo' : https://github.com/alexgheorghiu/diagramo
First hit on GitHub search of 'diagramo' (seems more complete) : https://github.com/neojjang/diagramo