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>
    <alltransclusions gatcontinue="Bandera|7871" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1620" ns="10" title="Plantilla:Ficha de videoconsola" />
      <page pageid="1712" ns="0" title="Canon Inc." />
      <page pageid="4095" ns="6" title="Archivo:Microbee, Melbourne Museum.jpg" />
      <page pageid="4476" ns="0" title="Samsung" />
      <page pageid="6070" ns="0" title="Sharp Corporation" />
      <page pageid="6326" ns="0" title="César Astudillo" />
      <page pageid="6392" ns="0" title="Sonic the Hedgehog" />
      <page pageid="6690" ns="0" title="Acorn Computers" />
      <page pageid="7752" ns="0" title="Amper" />
      <page pageid="8499" ns="0" title="Mandriva" />
    </pages>
  </query>
</api>