I can certainly look at offering a privately-hostable version eventually. It's running on a typical asp.net stack, so shouldn't be too hard to install elsewhere.
I'm currently focused on getting the public service out there, but if you're keen to get Jooplicate running locally please drop me an email andrew@equin.co.uk . It would be useful to know what kind of requirements you have.
Yes, for now it's HTML, which is better than nothing.
My plan for the future is to pass the HTML to a server-side browser renderer (using the user agent captured in the snapshot). So then you'll get a JPEG as well.
I'm trying to keep things simple for this initial version and iterate based on feedback.
Jooplicate is doing some tricky stuff in the background. For example, it's working cross-domain and sanitizing the HTML.
I work for a university that still is very hesitant on using cloud services, because they don't want student data going outside our machines.