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>
    <templates tlcontinue="1|10|NewEvent" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page">
        <templates>
          <tl ns="0" title="1st preCICE Workshop" />
          <tl ns="0" title="Contrib gdbOF" />
          <tl ns="0" title="Events/15th International OpenFOAM Workshop" />
          <tl ns="0" title="News/FEATool Multiphysics 1.8 with OpenFOAM MATLAB CFD GUI" />
          <tl ns="0" title="News/PFAU18 graz: July 3rd 2019 (Austrian User Meeting)" />
          <tl ns="0" title="PFAU 19 Austrian User Meeting" />
          <tl ns="10" title="Template:Frontpage Community" />
          <tl ns="10" title="Template:Frontpage Forks" />
          <tl ns="10" title="Template:Frontpage Learn" />
          <tl ns="10" title="Template:Frontpage Links" />
        </templates>
      </page>
    </pages>
  </query>
</api>