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="21" ns="0" title="Чайник" contentmodel="wikitext" pagelanguage="ru" touched="2008-07-22T19:11:41Z" lastrevid="529" counter="43132" length="1080" />
      <page pageid="25" ns="0" title="Метрополитен" contentmodel="wikitext" pagelanguage="ru" touched="2020-08-27T17:29:14Z" lastrevid="7330" counter="51400" length="2814" />
      <page pageid="66" ns="0" title="ОСТРОБ" contentmodel="wikitext" pagelanguage="ru" touched="2014-11-19T18:56:31Z" lastrevid="3176" counter="44797" length="1501" />
      <page pageid="128" ns="0" title="Крыса-мутант" contentmodel="wikitext" pagelanguage="ru" touched="2010-06-01T18:51:41Z" lastrevid="2605" counter="40640" length="1918" />
      <page pageid="129" ns="0" title="Танковый Тоннель" contentmodel="wikitext" pagelanguage="ru" touched="2008-07-24T10:39:40Z" lastrevid="548" counter="38102" length="943" />
      <page pageid="150" ns="0" title="Юлия Шавель" contentmodel="wikitext" pagelanguage="ru" touched="2012-12-06T13:33:58Z" lastrevid="4549" counter="38630" length="5629" />
      <page pageid="199" ns="0" title="Метрофорум" contentmodel="wikitext" pagelanguage="ru" touched="2009-06-04T19:28:09Z" lastrevid="1194" counter="53568" length="3015" />
      <page pageid="222" ns="0" title="Владимир Гарюгин" contentmodel="wikitext" pagelanguage="ru" touched="2012-12-06T14:09:57Z" lastrevid="4554" counter="27909" length="8094" />
    </pages>
  </query>
</api>