This gist page uses "me not know, but me know now" to express even a cave man can do it (no offense to cavemen).

I learned one thing: Apply XSL to an XML by editing the XML. But can we flip it?

The web works in MVC ways. Web servers are controllers that output the view populated with data.

(XML) Data is in the backend. (XSLT) View page is the front end. (XPath) Query filters is requesting (XML) data like controllers do.