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="Best_mold_inspector.gif" />
  </query-continue>
  <query>
    <pages>
      <page pageid="249" ns="6" title="File:Back hoe required to did out a septic tank drainfield.gif" />
      <page pageid="190" ns="6" title="File:Basement water mold.gif" />
      <page pageid="191" ns="6" title="File:Bathroom mold.gif" />
      <page pageid="229" ns="6" title="File:Bed Bug.jpg" />
      <page pageid="223" ns="6" title="File:Bed Bug Bites.jpg" />
      <page pageid="228" ns="6" title="File:Bed Bug Exterminator.gif" />
      <page pageid="232" ns="6" title="File:Bed Bugs in Hotel Rooms.jpg" />
      <page pageid="233" ns="6" title="File:Bed bug dogs.jpg" />
      <page pageid="224" ns="6" title="File:Bed bug pest control man.gif" />
      <page pageid="231" ns="6" title="File:Bed bugs on a blue sheet.jpg" />
    </pages>
  </query>
</api>