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>
    <allimages>
      <img name="Batch.png" timestamp="2009-10-12T20:38:30Z" url="http://mx.phenomix.org/images/e/e7/Batch.png" descriptionurl="http://mx.phenomix.org/index.php/File:Batch.png" ns="6" title="File:Batch.png" />
      <img name="BatchSmall.png" timestamp="2009-10-12T17:35:40Z" url="http://mx.phenomix.org/images/d/d1/BatchSmall.png" descriptionurl="http://mx.phenomix.org/index.php/File:BatchSmall.png" ns="6" title="File:BatchSmall.png" />
      <img name="Batch_pcr_ss.png" timestamp="2011-04-04T17:08:27Z" url="http://mx.phenomix.org/images/4/4e/Batch_pcr_ss.png" descriptionurl="http://mx.phenomix.org/index.php/File:Batch_pcr_ss.png" ns="6" title="File:Batch pcr ss.png" />
      <img name="Chr_show.png" timestamp="2008-09-28T01:43:15Z" url="http://mx.phenomix.org/images/9/93/Chr_show.png" descriptionurl="http://mx.phenomix.org/index.php/File:Chr_show.png" ns="6" title="File:Chr show.png" />
      <img name="Class_show.png" timestamp="2010-05-20T17:22:43Z" url="http://mx.phenomix.org/images/2/2d/Class_show.png" descriptionurl="http://mx.phenomix.org/index.php/File:Class_show.png" ns="6" title="File:Class show.png" />
      <img name="Content_template_show.png" timestamp="2008-09-27T18:26:30Z" url="http://mx.phenomix.org/images/f/f4/Content_template_show.png" descriptionurl="http://mx.phenomix.org/index.php/File:Content_template_show.png" ns="6" title="File:Content template show.png" />
      <img name="Edit_in_place_class.png" timestamp="2010-05-20T17:23:58Z" url="http://mx.phenomix.org/images/b/b2/Edit_in_place_class.png" descriptionurl="http://mx.phenomix.org/index.php/File:Edit_in_place_class.png" ns="6" title="File:Edit in place class.png" />
      <img name="Endnote_import.jpg" timestamp="2009-11-19T18:27:43Z" url="http://mx.phenomix.org/images/7/77/Endnote_import.jpg" descriptionurl="http://mx.phenomix.org/index.php/File:Endnote_import.jpg" ns="6" title="File:Endnote import.jpg" />
      <img name="Extract_terms_small.png" timestamp="2009-10-12T18:03:00Z" url="http://mx.phenomix.org/images/4/4a/Extract_terms_small.png" descriptionurl="http://mx.phenomix.org/index.php/File:Extract_terms_small.png" ns="6" title="File:Extract terms small.png" />
      <img name="FASTA_import.jpg" timestamp="2009-11-19T18:33:31Z" url="http://mx.phenomix.org/images/7/7d/FASTA_import.jpg" descriptionurl="http://mx.phenomix.org/index.php/File:FASTA_import.jpg" ns="6" title="File:FASTA import.jpg" />
    </allimages>
  </query>
  <query-continue>
    <allimages aicontinue="Filter_by_tags_small.png" />
  </query-continue>
</api>