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="Add.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="154" ns="6" title="File:Accessing Accounts.png" />
      <page pageid="1157" ns="6" title="File:Account.png" />
      <page pageid="1179" ns="6" title="File:AccountImport1.jpg" />
      <page pageid="170" ns="6" title="File:Account Management Screen.png" />
      <page pageid="172" ns="6" title="File:Account Summary.png" />
      <page pageid="1156" ns="6" title="File:Accounts Filter Enabled.png" />
      <page pageid="151" ns="6" title="File:Accounts List.png" />
      <page pageid="152" ns="6" title="File:Accounts Management.png" />
      <page pageid="167" ns="6" title="File:Accounts Manager.png" />
      <page pageid="153" ns="6" title="File:Accounts Manager Edit User.png" />
    </pages>
  </query>
</api>