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>
    <allpages gapcontinue="Regional_Live_CD" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1238" ns="0" title="Red Hat">
        <revisions>
          <rev contentformat="text/x-wiki" contentmodel="wikitext" xml:space="preserve">The [[Red Hat]] web site can be found at http://www.redhat.com.  Fedora Core is one of [[Red Hat | Red Hat's]] popular distributions because it is free and allows for community participation.

{{page-stub}}</rev>
        </revisions>
      </page>
      <page pageid="1182" ns="0" title="Redirection">
        <revisions>
          <rev contentformat="text/x-wiki" contentmodel="wikitext" xml:space="preserve">[[Redirection]]

First, you have input / output streams. This is where the keyboard (input) data or display (output) data is (normally) going to/from.

cmd &gt; write file &lt;br&gt;
cmd &lt; read file to pipe input in &lt;br&gt;
cmd &gt;&gt; append write file &lt;br&gt;
cmd 1&gt;log.out 2&gt;</rev>
        </revisions>
      </page>
    </pages>
  </query>
</api>