Verified answer

You opened an XML file , that opened in a browser that requires a stylesheet to see the xml file.

If you open it with the correct application or a simple program , You'll see the guts of the file.

http://getfirefox.com/ shows xml files with or without a stylesheet!

Is this a page *you* created somehow? If so, then, note that some software (or you) mistakenly places an <xml> statement as the very first statement at the top of a web page. This doesn't sit very well with some browsers depending on the <doctype> specified...The <xml> statement should be removed from the file.