What are the advantages of creating web pages with XML instead of HTML?

Question

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 w

Answer 1

One possible advantage would be for use of the data of the page in something other than a web browser; that would (presumably) be easier to do if a page's content were well-formed XML. Of course in theory a well-formed, semantic XHTML page should be nearly as able to be parsed, as well.

It can also be easier to generate XML instead of XHTML, depending on the data source.