Background on XML

• XML (Extensible Markup Language) : meta-syntax
• Simplified version of SGML
  
  
• HTML is one application of SGML, with one set of elements:

   <TITLE>XML and Accessibility</TITLE>
    <ADDRESS lang=fr>Daniel Dardailler</ADDRESS>
    <H1>Introduction</H1>
   

• In XML or SGML, on can define new elements:

   <MENU>Gastronomique</MENU>
    <ENTREE>Salade de Rougets
      <PHOTO url="sr.jpg">
         <DESC lang=fr>Une assiette de mache avec 3 rougets et des olives au centre</DESC>
         <DESC lang=en>A plate of salad with 3 mullets and olives in the center </DESC>      
      </PHOTO>
    </ENTREE>
   

Same issues of text equivalence, structure, etc as with "known" tagsets (HTML, SVG, SMIL...), plus new issue of unknown semantics.