Currently, when browsing XML files using Microsoft® Internet Explorer, the XML documents are not validated. In addition, when viewing the source of the document, only the XML is returned and there is no way to view the output from the XSL or XSLT style sheet that may have been used to transform that XML document. The Internet Explorer tools for validating XML and viewing XSLT output will enable a shell option when viewing XML files to see the processed XSL output. In addition, you can also validate XML against an embedded schema when loading XML via the Internet Explorer MIME viewer. This can be a useful tool when you are trying to debug XSL formatting problems in Internet Explorer or are doing quick schema validation.
Web Browsers / Internet Explorer
Internet Explorer Tools for Validating XML and Viewing XSLT Output