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>
    <allimages gaicontinue="Comp_menuboard_data.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="151" ns="6" title="File:Change res.png" />
      <page pageid="16" ns="6" title="File:Comp clock analog.png" />
      <page pageid="17" ns="6" title="File:Comp clock countdown.png" />
      <page pageid="18" ns="6" title="File:Comp clock digital.png" />
      <page pageid="8" ns="6" title="File:Comp configurations.png" />
      <page pageid="21" ns="6" title="File:Comp date.png" />
      <page pageid="117" ns="6" title="File:Comp enterprise.png" />
      <page pageid="130" ns="6" title="File:Comp interactivity.png" />
      <page pageid="66" ns="6" title="File:Comp layout background.png" />
      <page pageid="68" ns="6" title="File:Comp layout mask.png" />
    </pages>
  </query>
</api>