You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information.
<?xml version="1.0"?>
<api>
  <query-continue>
    <allcategories accontinue="To_be_deleted" />
  </query-continue>
  <query>
    <allcategories>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Comimg to SISSA</c>
      <c size="16" pages="16" files="0" subcats="0" xml:space="preserve">Coming to SISSA</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Coming to SISSA Coming to SISSA</c>
      <c size="28" pages="28" files="0" subcats="0" xml:space="preserve">Life in Trieste</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Life in Trieste Life in Trieste</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">Pages with broken file links</c>
      <c size="31" pages="31" files="0" subcats="0" xml:space="preserve">SISSA</c>
      <c size="0" pages="0" files="0" subcats="0" xml:space="preserve">SISSA Life in SISSA</c>
      <c size="2" pages="2" files="0" subcats="0" xml:space="preserve">Students' reps</c>
      <c size="6" pages="6" files="0" subcats="0" xml:space="preserve">To be checked</c>
    </allcategories>
  </query>
</api>