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>
    <alltransclusions gatcontinue="Dagger" />
  </query-continue>
  <query>
    <pages>
      <page ns="10" title="Malline:Copy to your site" missing="" />
      <page pageid="299" ns="10" title="Malline:CSS3 multiple column layout" />
      <page pageid="300" ns="10" title="Malline:Caution" />
      <page pageid="328" ns="10" title="Malline:Col-2" />
      <page pageid="327" ns="10" title="Malline:Col-begin" />
      <page pageid="329" ns="10" title="Malline:Col-end" />
      <page pageid="301" ns="10" title="Malline:Column-count" />
      <page pageid="302" ns="10" title="Malline:Column-generating template families" />
      <page pageid="303" ns="10" title="Malline:Column-rule" />
      <page pageid="304" ns="10" title="Malline:Column-width" />
    </pages>
  </query>
</api>