XML is a meta-language. You use it to define specific languages. Languages never do anything, they just allow us to express things. Also, it is not true that XML is a "storage language". Just the opposite, in fact. You can store XML docs however you please. XML is better thought of as a transfer language. PS. If you don't think XML "does" anything, you'll have to explain how it is that many systems (e.g. jetty) use XML as a (bad) programming language. It's a lamentable abuse of XML, but it exists in the wild, and that just one of many examples.
