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 ns="0" title="Content Manager/Setup" missing="" contentmodel="wikitext" pagelanguage="en-gb" />
      <page ns="0" title="Content Manager/System Requirements" missing="" contentmodel="wikitext" pagelanguage="en-gb" />
      <page pageid="6" ns="0" title="Composer" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-05-14T15:31:44Z" lastrevid="738" counter="35861" length="5546" />
      <page pageid="79" ns="0" title="Player" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-05-14T15:33:50Z" lastrevid="739" counter="8968" length="2699" />
      <page pageid="81" ns="0" title="Queue Management" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-03-19T18:00:48Z" lastrevid="266" counter="3005" length="616" />
      <page pageid="126" ns="0" title="Retail Analytics/Setup" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-04-30T20:48:32Z" lastrevid="734" counter="3887" length="1638" />
      <page pageid="134" ns="0" title="Retail Analytics/System Requirements" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-02-26T11:15:20Z" lastrevid="582" counter="2437" length="528" />
      <page pageid="2" ns="0" title="Setup" contentmodel="wikitext" pagelanguage="en-gb" touched="2013-04-28T15:36:37Z" lastrevid="707" counter="13921" length="3269" />
    </pages>
  </query>
</api>