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="XMREngine Script Engine" contentmodel="wikitext" pagelanguage="en" touched="2018-04-07T14:07:36Z" lastrevid="20" counter="15605" length="2739" />
      <page pageid="5" ns="0" title="In-world Currency" contentmodel="wikitext" pagelanguage="en" touched="2015-02-03T21:47:56Z" lastrevid="6" counter="9088" length="388" new="" />
      <page pageid="6" ns="0" title="Ephemeral Groups" contentmodel="wikitext" pagelanguage="en" touched="2015-02-03T21:48:36Z" lastrevid="7" counter="9326" length="3393" new="" />
      <page pageid="7" ns="0" title="Chat/IM Language Translator" contentmodel="wikitext" pagelanguage="en" touched="2015-02-03T21:49:09Z" lastrevid="8" counter="8822" length="3523" new="" />
      <page pageid="17" ns="0" title="Add DreamNation to your Viewer (Cool VL Viewer)" contentmodel="wikitext" pagelanguage="en" touched="2015-02-03T22:17:00Z" lastrevid="18" counter="12463" length="346" new="" />
      <page pageid="18" ns="0" title="Add DreamNation to your Viewer (Singularity)" contentmodel="wikitext" pagelanguage="en" touched="2015-02-03T22:18:06Z" lastrevid="19" counter="15228" length="697" new="" />
    </pages>
  </query>
</api>