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="2" ns="0" title="Main Page" contentmodel="wikitext" pagelanguage="en" touched="2015-04-08T09:03:42Z" lastrevid="16842" counter="584714" length="3850" />
      <page pageid="3543" ns="0" title="All Cards" contentmodel="wikitext" pagelanguage="en" touched="2015-04-09T17:55:16Z" lastrevid="16026" counter="13241" length="5616" />
      <page pageid="3562" ns="10" title="Template:TitleAndCard" contentmodel="wikitext" pagelanguage="en" touched="2015-04-09T21:57:48Z" lastrevid="9490" counter="5350" length="37" />
      <page pageid="3567" ns="0" title="Random Card" contentmodel="wikitext" pagelanguage="en" touched="2015-04-09T17:55:16Z" lastrevid="15363" counter="22340" length="2985" />
      <page pageid="3602" ns="0" title="Deck as PDF" contentmodel="wikitext" pagelanguage="en" touched="2015-04-07T08:55:39Z" lastrevid="16617" counter="77584" length="2454" />
      <page pageid="6112" ns="0" title="All Discussions" contentmodel="wikitext" pagelanguage="en" touched="2015-04-08T09:03:42Z" lastrevid="15717" counter="1388" length="5928" />
      <page pageid="6116" ns="0" title="Exp17" contentmodel="wikitext" pagelanguage="en" touched="2015-04-09T17:55:16Z" lastrevid="15875" counter="9333" length="644" />
      <page pageid="6120" ns="0" title="New Main Page" contentmodel="wikitext" pagelanguage="en" touched="2015-04-08T09:03:42Z" lastrevid="16252" counter="27310" length="4299" />
      <page pageid="6123" ns="0" title="New Main Page 2" contentmodel="wikitext" pagelanguage="en" touched="2015-04-08T09:03:42Z" lastrevid="15982" counter="5805" length="3849" />
    </pages>
  </query>
</api>