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>
    <alllinks galcontinue="К_вопросу_о_клонировании_человека_в_третьем_рейхе|243" />
  </query-continue>
  <query>
    <pages>
      <page pageid="8" ns="8" title="MediaWiki:Common.css" />
      <page pageid="243" ns="14" title="Категория:Публикации" />
      <page pageid="265" ns="0" title="Статьи БМ Моносова" />
      <page pageid="279" ns="10" title="Шаблон:Публикации" />
    </pages>
  </query>
</api>