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="Basic_definition|117" />
  </query-continue>
  <query>
    <pages>
      <page pageid="10" ns="0" title="Normal space" />
      <page pageid="11" ns="0" title="Characteristic subgroup" />
      <page pageid="25" ns="0" title="Group (mathematics)" />
      <page pageid="33" ns="0" title="Dimension of a vector space" />
      <page pageid="40" ns="0" title="Simple" />
      <page pageid="43" ns="0" title="Normal form (linear algebra)" />
      <page pageid="53" ns="0" title="Perfect matching" />
      <page pageid="55" ns="0" title="Perfect power" />
      <page pageid="76" ns="0" title="Regular space" />
      <page pageid="149" ns="0" title="Center" />
    </pages>
  </query>
</api>