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>
    <allpages apcontinue="Barbaras_24.10.07" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="1174" ns="0" title="BNR" />
      <p pageid="76" ns="0" title="Barbara" />
      <p pageid="153" ns="0" title="Barbara geht einkaufen" />
      <p pageid="314" ns="0" title="Barbara handelt" />
      <p pageid="332" ns="0" title="Barbara im Spital" />
      <p pageid="277" ns="0" title="Barbara im Zentral CDs" />
      <p pageid="276" ns="0" title="Barbara liest die Pressemitteilung" />
      <p pageid="305" ns="0" title="Barbara und Gilles streiten sich" />
      <p pageid="230" ns="0" title="Barbaras 09.11.07" />
      <p pageid="257" ns="0" title="Barbaras 14.11.07" />
    </allpages>
  </query>
</api>