You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allimages gaifrom="Simulink SupportedBlocksSinksSources.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="4" ns="6" title="File:HelloWorld1.jpg" />
      <page pageid="2" ns="6" title="File:HelloWorld2.jpg" />
      <page pageid="25" ns="6" title="File:MediaWikiSidebarLogo.png" />
      <page pageid="6" ns="6" title="File:Simulink SupportedBlocksAll.jpg" />
      <page pageid="7" ns="6" title="File:Simulink SupportedBlocksDiscrete.jpg" />
      <page pageid="8" ns="6" title="File:Simulink SupportedBlocksLogicalBit.jpg" />
      <page pageid="9" ns="6" title="File:Simulink SupportedBlocksLookup.jpg" />
      <page pageid="10" ns="6" title="File:Simulink SupportedBlocksMath.jpg" />
      <page pageid="5" ns="6" title="File:Simulink SupportedBlocksMisc.jpg" />
      <page pageid="11" ns="6" title="File:Simulink SupportedBlocksSignalRouting.jpg" />
    </pages>
  </query>
</api>