The latest version of the GUI is available publicly at http://rackhd.github.io/on-web-ui you can also download a zip of the latest version.
This zip file can be extracted inside “on-http/static/http” to serve the UI from the MonoRail API server.
Source code for the web user interface is available at https://github.com/RackHD/on-web-ui. There is also a README for learning how to about UI development.