Sometime, you have to retrieve an xml document from a remote site (like wsdl for a webservice or whatever). But often, you get a flat file unreadable.
To obtain a pretty-print xml document, throw it content into xmllint as follow:
curl http://server/remotefile.xml | xmllint --format -
You can obtain your document from a remote server via ssh as well.
ssh account@server 'cat remotefile.xml' | xmllint --format -