From time to time, I see web pages whose content is solely written in XML (not HTML or XHTML). These pages usually have some style sheets (either XSLT or CSS) attached to them which makes them look like any other ordinary web page.
My question is, what are the advantages of such an approach (if any), and why would anyone choose to work this way?
EDIT: If this is a good thing, why is it not widespread?
EDIT 2: Thanks everyone for the great responses. They really enlightened me. I also found this question whose content is also related.
It’s easier to generate it programmatically and reuse it for other purposes than displaying as webpage.
Update:
Not everyone needs to generate it programmatically or reuse it for other purposes than displaying as webpage. It’s then easier to use plain HTML.