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="Binding_energy_15.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="68" ns="6" title="File:Associated Sub Issues.JPG" />
      <page pageid="115" ns="6" title="File:Benefit of Object Oriented Documentation.xls" />
      <page pageid="1672" ns="6" title="File:Binding Energy Graph.png">
        <duplicatefiles>
          <df name="Binding_Energy_fig_7.png" user="Thorlp" timestamp="2012-01-29T15:18:05Z" />
        </duplicatefiles>
      </page>
      <page pageid="2068" ns="6" title="File:Binding Energy fig 7.png">
        <duplicatefiles>
          <df name="Binding_Energy_Graph.png" user="Thorlp" timestamp="2011-11-30T15:32:40Z" />
        </duplicatefiles>
      </page>
      <page pageid="2036" ns="6" title="File:Binding energy 1.png" />
      <page pageid="2045" ns="6" title="File:Binding energy 10.png" />
      <page pageid="2046" ns="6" title="File:Binding energy 11.png" />
      <page pageid="2047" ns="6" title="File:Binding energy 12.png" />
      <page pageid="2048" ns="6" title="File:Binding energy 13.png" />
      <page pageid="2049" ns="6" title="File:Binding energy 14.png" />
    </pages>
  </query>
</api>