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="Butter.jpg|1005" />
  </query-continue>
  <query>
    <pages>
      <page pageid="286" ns="0" title="Withdrawing jurisdiction" />
      <page pageid="976" ns="2" title="User:Achoicenotanecho/Userpage 3" />
      <page pageid="977" ns="2" title="User:Conservative/Personal development skill sets etc" />
      <page pageid="978" ns="2" title="User:Conservative/Christianity" />
      <page pageid="981" ns="2" title="User:Conservative/Music various types" />
      <page pageid="985" ns="2" title="User:Achoicenotanecho/Classical music" />
      <page pageid="1001" ns="2" title="User:Conservative/Cognitive performance" />
      <page pageid="1002" ns="2" title="User:Conservative/Classical and related music" />
      <page pageid="1005" ns="2" title="User:Achoicenotanecho/IR" />
    </pages>
  </query>
</api>