The software used was a commercial tool made upon Guacamole (Apache) called Inuvika. It's pretty awful, but having Linux and Windows apps on the same virtual desktop is quite cool. I don't know how much of that functionality comes from Guacamole or from the Inuvika addons.

Inuvika/Guacamole also support plain RDP, but we didn't use this, just the html5 client (browser)

If you want to see what open-source can do then look at Guacamole and go from there.

Don't think that helps, but...