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="551" ns="0" title="Шарипов, Ади Шарипович" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-19T03:34:16Z" lastrevid="1102" counter="1829" length="4600" />
      <page pageid="1252" ns="0" title="Список улиц Алма-Аты" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-18T13:59:42Z" lastrevid="2504" counter="2996" length="32497" />
      <page pageid="1454" ns="0" title="Сейталиев, Токтоналы" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-19T03:04:52Z" lastrevid="2908" counter="763" length="8382" />
      <page pageid="1814" ns="0" title="Казахский государственный академический театр для детей и юношества имени Г. Мусрепова" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-19T03:27:56Z" lastrevid="3631" counter="1216" length="11211" />
      <page pageid="1915" ns="0" title="Балкаш-Шокпарское восстание" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-18T18:54:35Z" lastrevid="3833" counter="942" length="19259" />
      <page pageid="5002" ns="0" title="Казы-карта" contentmodel="wikitext" pagelanguage="ru" touched="2017-04-19T03:27:30Z" lastrevid="10019" counter="1535" length="8754" />
    </pages>
  </query>
</api>