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="Come_Iniziare.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="286" ns="6" title="File:4d74febfd5732campagna bilanci home page.jpg" />
      <page pageid="183" ns="6" title="File:AGREEMENT FOR ALLOCATION OF COSTS.pdf" />
      <page pageid="181" ns="6" title="File:Agency agreement.pdf" />
      <page pageid="15226" ns="6" title="File:Areaclienti.pdf" />
      <page pageid="15227" ns="6" title="File:Arearis.jpg" />
      <page pageid="220" ns="6" title="File:Atto di citazione per disconoscimento di paternità.doc" />
      <page pageid="184" ns="6" title="File:BYLAWS OF newco.pdf" />
      <page pageid="136" ns="6" title="File:Brochure.doc" />
      <page pageid="56" ns="6" title="File:By-nc-sa.eu.png" />
      <page pageid="180" ns="6" title="File:COMMERCIAL LEASE.pdf" />
    </pages>
  </query>
</api>