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>
    <allimages gaicontinue="04b_pyramid_tn_new.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="964" ns="6" title="File:01 box tn.jpg" />
      <page pageid="1221" ns="6" title="File:02a cylinder tn.jpg" />
      <page pageid="1206" ns="6" title="File:02b cylinder tn.jpg" />
      <page pageid="5992" ns="6" title="File:02b cylinder tn new.png" />
      <page pageid="1180" ns="6" title="File:03 freespace tn.gif" />
      <page pageid="741" ns="6" title="File:03a cone tn.jpg" />
      <page pageid="726" ns="6" title="File:03b cone tn.jpg" />
      <page pageid="5994" ns="6" title="File:03b cone tn new.png" />
      <page pageid="1187" ns="6" title="File:04a pyramid tn.jpg" />
      <page pageid="1056" ns="6" title="File:04b pyramid tn.jpg" />
    </pages>
  </query>
</api>