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>
    <allpages gapcontinue="Булевы_функции_и_полиномы" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1166" ns="0" title="Актуальные математические задачи, связанные с проектированием СБИС" contentmodel="wikitext" pagelanguage="ru" touched="2023-08-29T10:59:41Z" lastrevid="10367" counter="2548" length="3211" />
      <page pageid="78" ns="0" title="Алексеев Валерий Борисович" contentmodel="wikitext" pagelanguage="ru" touched="2022-03-10T17:22:26Z" lastrevid="8958" counter="4210" length="251" redirect="" />
      <page pageid="21" ns="0" title="Архитектурные особенности современных вычислительных систем" contentmodel="wikitext" pagelanguage="ru" touched="2019-02-09T15:03:19Z" lastrevid="5837" counter="6656" length="5268" />
      <page pageid="1736" ns="0" title="Большие графы и модели сложных сетей" contentmodel="wikitext" pagelanguage="ru" touched="2023-04-02T19:53:21Z" lastrevid="10180" counter="11631" length="12480" />
    </pages>
  </query>
</api>