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>
    <allredirects garcontinue="History_of_Computers_-_Schrodinger&#039;s_Cat" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="History of Computer - The Athlon Processor" missing="" />
      <page pageid="996" ns="0" title="Earth Science 7- Antarctica/ Australia/ New Zealand Period 1" />
      <page pageid="770" ns="0" title="Earth Science 7- Bangui, Central African Republic" />
      <page pageid="2147" ns="0" title="History of Computers - Alan Turing" />
      <page pageid="1365" ns="0" title="History of Computers - CorelDRAW" />
      <page pageid="2883" ns="0" title="History of Computers - Douglas Engelbart" />
      <page pageid="1375" ns="0" title="History of Computers - Norbert Wiener" />
      <page pageid="625" ns="0" title="History of Computers - Origins of IBM" />
      <page pageid="335" ns="0" title="History of Computers - Projection Keyboard" />
      <page pageid="1374" ns="0" title="History of Computers - Push Technology" />
    </pages>
  </query>
</api>