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="1940_-_La_California_b.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="146" ns="6" title="File:08-noi siamo livornesi.ogg" />
      <page pageid="100" ns="6" title="File:1795-VISITA VESCOVO ALLIATA.pdf" />
      <page pageid="93" ns="6" title="File:1840 Map of Florence, Alabama.jpeg">
        <duplicatefiles>
          <df name="1840_Map_of_Florence,_Alabama.jpeg" user="Spyder Monkey" timestamp="2009-06-29T22:01:41Z" shared="" />
        </duplicatefiles>
      </page>
      <page pageid="120" ns="6" title="File:1886-VISITA VESCOVO GELLI.pdf" />
      <page pageid="290" ns="6" title="File:1925 - Braccio di Bibbona.jpg" />
      <page pageid="291" ns="6" title="File:1930 - Braccio di Bibbona.jpg" />
      <page pageid="292" ns="6" title="File:1935 - Braccio di Bibbona, Ferruccio Demi.jpg" />
      <page pageid="293" ns="6" title="File:1935 - Osteria Gabbani.jpg" />
      <page pageid="294" ns="6" title="File:1938 - cerimonia per l&#039;arrivo delll&#039;elettricità.jpg" />
      <page pageid="295" ns="6" title="File:1940 - La California a.jpg" />
    </pages>
  </query>
</api>