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>
    <pages>
      <page pageid="57" ns="0" title="Center for Systemic Peace" />
      <page pageid="43" ns="0" title="Global Health Observatory (GHO)" />
      <page pageid="108" ns="0" title="International Diabetes Federation" />
      <page pageid="30" ns="0" title="International Energy Agency (IEA)" />
      <page pageid="1" ns="0" title="International Futures (IFs)" />
      <page pageid="89" ns="0" title="OECD Statistics Database Online" />
      <page pageid="1739" ns="0" title="Social Accounting Matrix (SAM)" />
      <page pageid="55" ns="0" title="World Resources Institute (WRI)" />
    </pages>
  </query>
</api>