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="S&amp;D-Kendal_Multiview_Market.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="274" ns="6" title="File:Camms Yard 89 Stricklandgate -An Old Kendal Yard.jpg" />
      <page pageid="199" ns="6" title="File:Dowker&#039;s Hospital Reduced Rules.jpg" />
      <page pageid="200" ns="6" title="File:Dowker&#039;s Hospital Stengal E16342.jpg" />
      <page pageid="165" ns="6" title="File:Finkle Street Old Pump Inn Fish Market JHHogg.png" />
      <page pageid="229" ns="6" title="File:Gillinggate Roods Terrace.jpg" />
      <page pageid="166" ns="6" title="File:Greenside.png" />
      <page pageid="299" ns="6" title="File:James-Kerr-Murray-Ironmonger-Advert-53-Stricklandgate.jpg" />
      <page pageid="64" ns="6" title="File:Kirkland Yard 23 Curwen1900.png" />
      <page pageid="223" ns="6" title="File:Liverpool and Kendal Stage Coach Advert 1768 Kings Arms.jpg" />
      <page pageid="33" ns="6" title="File:Rose and Crown Inn pre1876.jpg" />
    </pages>
  </query>
</api>