Hritserver has progressed to version 0.1.2. It can generate HTML for compare view, with parallel texts that will be able to syncro-scroll, plain HTML versions, a dropdown menu to select versions, and a few services like stripping XML into markup and plain text. The back-end is also taking shape:
The idea here is to build up a web page in any web-development system whatsoever from a series of configurable components. Each component is just a fragment of HTML whose formatting and markup can be specified by the user. When I say markup I don't mean XML, I mean standoff properties. So you can have multiple markup sets and stylesheets for one text that combine sensibly. Or you can just ask for that component and let the default formatting do all the hard work for you.
The back-end shown above in a very early version is supposed to be a 'reference implementation' that fully exercises the HritServer application. So you can see what it is capable of and how to do it at the same time.