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>
    <allimages gaicontinue="2._Index_db._png.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="149" ns="6" title="File:1.1 Search Button.PNG" />
      <page pageid="168" ns="6" title="File:1.Automatic Indexer.png" />
      <page pageid="166" ns="6" title="File:1. Index Config.PNG" />
      <page pageid="148" ns="6" title="File:1. Quick Find.png" />
      <page pageid="158" ns="6" title="File:10. Reset.PNG" />
      <page pageid="161" ns="6" title="File:12 LoadSaveEdit Queries.PNG" />
      <page pageid="162" ns="6" title="File:13. Save Query.PNG" />
      <page pageid="163" ns="6" title="File:14. Loadquery.PNG" />
      <page pageid="159" ns="6" title="File:15. Search View.PNG" />
      <page pageid="160" ns="6" title="File:16. Quick View.PNG" />
    </pages>
  </query>
</api>