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>
    <links gplcontinue="1|0|Batch_system_status" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4681" ns="0" title="ARC6 EL9" contentmodel="wikitext" pagelanguage="en" touched="2023-12-12T12:12:58Z" lastrevid="21504" counter="1195" length="4745" />
      <page pageid="4226" ns="0" title="ARGO Nagios Monitoring" contentmodel="wikitext" pagelanguage="en" touched="2016-09-27T15:51:20Z" lastrevid="12500" counter="9235" length="949" />
      <page pageid="3680" ns="0" title="ARGUS deployment" contentmodel="wikitext" pagelanguage="en" touched="2014-10-29T15:35:53Z" lastrevid="6525" counter="21226" length="5959" />
      <page pageid="1956" ns="0" title="ATLAS Monitoring For Sites" contentmodel="wikitext" pagelanguage="en" touched="2015-04-30T13:28:45Z" lastrevid="8277" counter="8164" length="3355" />
      <page pageid="3903" ns="0" title="ATLAS Site Availability and Performance (ASAP)" contentmodel="wikitext" pagelanguage="en" touched="2017-08-13T13:44:05Z" lastrevid="15222" counter="31988" length="5488" />
      <page pageid="2590" ns="0" title="ATLAS Software Installation" contentmodel="wikitext" pagelanguage="en" touched="2010-09-29T17:22:18Z" lastrevid="2590" counter="6720" length="1361" />
      <page pageid="3759" ns="0" title="A quick guide to CVMFS" contentmodel="wikitext" pagelanguage="en" touched="2015-12-02T13:35:32Z" lastrevid="10105" counter="32152" length="6510" />
      <page pageid="3617" ns="0" title="Adoption of Backup GridPP Voms Servers" contentmodel="wikitext" pagelanguage="en" touched="2014-04-15T13:23:23Z" lastrevid="3993" counter="14315" length="11959" />
      <page pageid="3391" ns="0" title="Argus Server" contentmodel="wikitext" pagelanguage="en" touched="2019-03-18T09:40:17Z" lastrevid="19653" counter="38257" length="12346" />
      <page pageid="1729" ns="0" title="Atlas FCR Procedure" contentmodel="wikitext" pagelanguage="en" touched="2007-04-25T14:06:28Z" lastrevid="1729" counter="5862" length="1005" />
    </pages>
  </query>
</api>