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>
    <images gimcontinue="1|Flags_fr.gif" />
  </query-continue>
  <query>
    <pages>
      <page pageid="154" ns="6" title="File:Flags ae.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="180" counter="8983" length="0" new="" />
      <page pageid="155" ns="6" title="File:Flags ar.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="181" counter="5739" length="0" new="" />
      <page pageid="156" ns="6" title="File:Flags bg.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="182" counter="6060" length="0" new="" />
      <page pageid="157" ns="6" title="File:Flags br.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="183" counter="5252" length="0" new="" />
      <page pageid="158" ns="6" title="File:Flags cz.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="184" counter="8237" length="0" new="" />
      <page pageid="159" ns="6" title="File:Flags de.gif" contentmodel="wikitext" pagelanguage="en" touched="2012-01-05T01:28:34Z" lastrevid="185" counter="30269" length="0" new="" />
      <page pageid="160" ns="6" title="File:Flags dk.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="186" counter="4247" length="0" new="" />
      <page pageid="161" ns="6" title="File:Flags en.png" contentmodel="wikitext" pagelanguage="en" touched="2012-02-13T13:13:19Z" lastrevid="187" counter="37217" length="0" new="" />
      <page pageid="162" ns="6" title="File:Flags es.gif" contentmodel="wikitext" pagelanguage="en" touched="2012-01-20T12:31:53Z" lastrevid="188" counter="7173" length="0" new="" />
      <page pageid="163" ns="6" title="File:Flags fi.gif" contentmodel="wikitext" pagelanguage="en" touched="2011-10-24T14:26:40Z" lastrevid="189" counter="7807" length="0" new="" />
    </pages>
  </query>
</api>