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="InViu_routes_v4.0_main_screen.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="59" ns="6" title="File:CellID info.png" />
      <page pageid="896" ns="6" title="File:Cell Information.png" />
      <page pageid="185" ns="6" title="File:Cellid.pdf" />
      <page pageid="895" ns="6" title="File:Device Details.png" />
      <page pageid="52" ns="6" title="File:ENAiKOON-keypad-mapper-31-en-gps precision.png" />
      <page pageid="53" ns="6" title="File:ENAiKOON-keypad-mapper-31-en-keypad.png" />
      <page pageid="887" ns="6" title="File:How to contribute headline.png" />
      <page pageid="805" ns="6" title="File:Identical sid and mnc.png" />
      <page pageid="54" ns="6" title="File:InViu OpenCellID v2.0 main screen.png" />
      <page pageid="55" ns="6" title="File:InViu OpenCellID v2.0 settings.png" />
    </pages>
  </query>
</api>