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>
    <querypage qpoffset="10" />
  </query-continue>
  <query>
    <querypage name="Ancientpages">
      <results>
        <page value="20131113133135" timestamp="2013-11-13T13:31:35Z" ns="0" title="Distretti nel comune di Bari" />
        <page value="20140113143052" timestamp="2014-01-13T14:30:52Z" ns="0" title="Portal:Header" />
        <page value="20140212153342" timestamp="2014-02-12T15:33:42Z" ns="0" title="Distretto 6 Bari ovest" />
        <page value="20140217105442" timestamp="2014-02-17T10:54:42Z" ns="0" title="Distretto 6 Bari Centro" />
        <page value="20140227102633" timestamp="2014-02-27T10:26:33Z" ns="0" title="Distretti sanitari nella Provincia di Bari" />
        <page value="20140227102804" timestamp="2014-02-27T10:28:04Z" ns="0" title="Distretti sanitari nella Provincia di Bologna" />
        <page value="20140227103033" timestamp="2014-02-27T10:30:33Z" ns="0" title="Distretti sanitari nella Provincia di Palermo" />
        <page value="20140227103219" timestamp="2014-02-27T10:32:19Z" ns="0" title="Distretti sanitari nella Provincia di Cagliari" />
        <page value="20140305092535" timestamp="2014-03-05T09:25:35Z" ns="0" title="Distretti sanitari nella Provincia di Roma" />
        <page value="20140305093134" timestamp="2014-03-05T09:31:34Z" ns="0" title="Distretto G4" />
      </results>
    </querypage>
  </query>
</api>