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>
    <alllinks galcontinue="Software_resources" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Joining the discussion" missing="" />
      <page pageid="18" ns="0" title="Backups" />
      <page pageid="23" ns="0" title="File and directory permissions and ownership" />
      <page pageid="22" ns="0" title="Guidelines and Terms of use" />
      <page pageid="14" ns="0" title="Hardware resources" />
      <page pageid="11" ns="0" title="Logging in to a terminal session" />
      <page pageid="21" ns="0" title="Migrating your data safely" />
      <page pageid="2" ns="0" title="Obtaining an account" />
      <page pageid="12" ns="0" title="Running jobs on our servers" />
      <page pageid="24" ns="0" title="Safety and security at the Lab" />
    </pages>
  </query>
</api>