Why an XML-based HTML?
    ... when we already have "normal" HTML?
    
    - Access to the strengths of XML:
      
        - Extensibility
 
        - Interoperability
 
      
     
    - Developers can extend XHTML
      
        - Modules
 
        - DTDs
 
        - Schemas
 
        - other XML-based languages
 
      
     
    - Developers can subset XHTML
 
    - XSLT Transformations
 
    - Makes it easy to adapt pages for a wide variety of
    user agents (such as browsers).