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>
    <allfileusages gafcontinue="CurationManual_10.gif" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1411" ns="6" title="File:Comp1.jpg" />
      <page pageid="1412" ns="6" title="File:Comp2.jpg" />
      <page pageid="1368" ns="6" title="File:CurationManual 01.gif" />
      <page pageid="1369" ns="6" title="File:CurationManual 02.gif" />
      <page pageid="1370" ns="6" title="File:CurationManual 03.gif" />
      <page pageid="1372" ns="6" title="File:CurationManual 05.gif" />
      <page pageid="1373" ns="6" title="File:CurationManual 06.gif" />
      <page pageid="1374" ns="6" title="File:CurationManual 07.gif" />
      <page pageid="1375" ns="6" title="File:CurationManual 08.gif" />
      <page pageid="1376" ns="6" title="File:CurationManual 09.gif" />
    </pages>
  </query>
</api>