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>
    <allpages apcontinue="Implementation" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="34" ns="0" title="Circumferential and Radial measurements" />
      <p pageid="1" ns="0" title="CometWiki" />
      <p pageid="4" ns="0" title="Cometparams.ini parameter file" />
      <p pageid="45" ns="0" title="Description of the Model" />
      <p pageid="17" ns="0" title="Detailed Program Flow" />
      <p pageid="30" ns="0" title="Display settings" />
      <p pageid="35" ns="0" title="Ellipsoid and Capsule symmetry breaking" />
      <p pageid="8" ns="0" title="Examples" />
      <p pageid="33" ns="0" title="Forces during Symmetry Breaking" />
      <p pageid="46" ns="0" title="How comet works" />
    </allpages>
  </query>
</api>