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="Bordcomputer" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="1291" ns="0" title="BMW Z3" />
      <p pageid="1326" ns="0" title="BMW Z3 FAQ" />
      <p pageid="1557" ns="0" title="BMW Z3 Geschichte" />
      <p pageid="1728" ns="0" title="BMW Z3 Typklassen / Versicherung" />
      <p pageid="1295" ns="0" title="BMW Z3 roadster" />
      <p pageid="1300" ns="0" title="BMW Z3 roadster 1.9 16V" />
      <p pageid="1289" ns="0" title="BMW Z4 Roadster" />
      <p pageid="1467" ns="0" title="Bastuck" />
      <p pageid="1556" ns="0" title="Becherhalter" />
      <p pageid="1768" ns="0" title="Beleuchtung" />
    </allpages>
  </query>
</api>