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="TB_AFB_smear.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="31372" ns="6" title="Tập tin:T0501.gif" imagerepository="local">
        <imageinfo>
          <ii timestamp="2009-05-21T14:48:30Z" user="Ngocluy" />
        </imageinfo>
      </page>
      <page pageid="31385" ns="6" title="Tập tin:T0502.gif" imagerepository="local">
        <imageinfo>
          <ii timestamp="2009-05-21T14:59:06Z" user="Ngocluy" />
        </imageinfo>
      </page>
      <page pageid="31092" ns="6" title="Tập tin:T9.1.jpg" imagerepository="local">
        <imageinfo>
          <ii timestamp="2009-05-20T13:41:21Z" user="DuongDuc" />
        </imageinfo>
      </page>
      <page pageid="28682" ns="6" title="Tập tin:TBT Bao dien tu Dan tri Pham Huy Hoan phat bieu khai mac NTDT2008.jpg" imagerepository="local">
        <imageinfo>
          <ii timestamp="2008-11-21T14:44:50Z" user="Nam Hy Hoàng Phong" />
        </imageinfo>
      </page>
    </pages>
  </query>
</api>