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="Basemesh_arshlevon_toes.obj" />
  </query-continue>
  <query>
    <pages>
      <page pageid="603" ns="6" title="File:BRDF Brice-Vandemoortele.jpg" />
      <page pageid="569" ns="6" title="File:Basemesh 01.gif" />
      <page pageid="1376" ns="6" title="File:Basemesh 01.obj.zip" />
      <page pageid="1456" ns="6" title="File:Basemesh Body Anzhou.zip" />
      <page pageid="1457" ns="6" title="File:Basemesh Bust Anzhou.zip" />
      <page pageid="570" ns="6" title="File:Basemesh anzhou body.gif" />
      <page pageid="571" ns="6" title="File:Basemesh anzhou bust.gif" />
      <page pageid="572" ns="6" title="File:Basemesh arshlevon shoes.gif" />
      <page pageid="1444" ns="6" title="File:Basemesh arshlevon shoes.obj" />
      <page pageid="573" ns="6" title="File:Basemesh arshlevon toes.gif" />
    </pages>
  </query>
</api>