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 afcontinue="CurationManual_07.gif|1367" />
  </query-continue>
  <query>
    <allfileusages>
      <f fromid="1383" ns="6" title="File:Comp1.jpg" />
      <f fromid="1383" ns="6" title="File:Comp2.jpg" />
      <f fromid="1367" ns="6" title="File:CurationManual 01.gif" />
      <f fromid="1384" ns="6" title="File:CurationManual 01.gif" />
      <f fromid="1367" ns="6" title="File:CurationManual 02.gif" />
      <f fromid="1383" ns="6" title="File:CurationManual 02.gif" />
      <f fromid="1367" ns="6" title="File:CurationManual 03.gif" />
      <f fromid="1367" ns="6" title="File:CurationManual 05.gif" />
      <f fromid="1383" ns="6" title="File:CurationManual 05.gif" />
      <f fromid="1367" ns="6" title="File:CurationManual 06.gif" />
    </allfileusages>
  </query>
</api>