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="08._Partitioning_C.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="12178" ns="6" title="File:00. Point Linux Logo.PNG" />
      <page pageid="12179" ns="6" title="File:01 Start from cd.png" />
      <page pageid="12180" ns="6" title="File:02 Start the Installmanager.png" />
      <page pageid="12181" ns="6" title="File:03. Language selection.png" />
      <page pageid="12182" ns="6" title="File:04. Timezone.png" />
      <page pageid="12183" ns="6" title="File:05. Keyboardlayout.png" />
      <page pageid="12184" ns="6" title="File:06. Creating a User.png" />
      <page pageid="12185" ns="6" title="File:07. Select hard disk for Installation.png" />
      <page pageid="12186" ns="6" title="File:08. Partitioning A.png" />
      <page pageid="12187" ns="6" title="File:08. Partitioning B.png" />
    </pages>
  </query>
</api>