http://www.webdevout.net/articles/beware-of-xhtml

   1.  What is XHTML?
   2. Myths of XHTML
   3. Benefits of XML
   4. Content type is everything
   5. HTML compatibility guidelines
   6. Internet Explorer incompatibility
   7. Content negotiation
   8. Null End Tags (NET)
   9. Firefox and other problems
  10. Conclusion
  11. List of standards-related sites that break as XHTML
  12. List of standards-related sites that stick with HTML
  13. Related sites
  14. See also