Extensible Hypertext Markup Language (XHTML) Classroom Training and Certification Classes

In the absence of other markup languages, XHTML would not make much difference, however you will get more advantages as more and more XML tools become available. Web applications that is concerned with semantics acquire more advantages of using XHTML

In order to make a HTML document in XML format, you would need to make necessary changes to convert it to proper XML because HTML is not in XML format in general.

When all the browsers are expected to do the same thing, the mechanism of error detection makes the browsers very hard to write. Added to this, HTML browsers accept any input irrespective of the correctness of the value in order to derive more sensibility from it. Therefore the author is left with no clues of the errors that they would make and this seems to be a big discrepancy for the new user agents as HTML documents are often so poor.