• simple markup language

<para>You can use <application>Emacs</application> for
editing your text files.</para>
  • markup creates documents with a rich information content

    • semantics is important

    • presentation (formatting) is not important at this stage

  • XML schema defines set of elements that can be used to markup document content

    • various syntaxes for XML schemas: DTD, W3C XML Schema, RELAX NG