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="Baustelle_8A_2014/2015" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="3941" ns="0" title="BAM" />
      <p pageid="3892" ns="0" title="BESEN" />
      <p pageid="1317" ns="0" title="Ballett" />
      <p pageid="489" ns="0" title="Barock" />
      <p pageid="2488" ns="0" title="Basketball" />
      <p pageid="2029" ns="0" title="Baustelle: Bewegungsgesetze GK2" />
      <p pageid="2765" ns="0" title="Baustelle: Elastischer Stoß GK2" />
      <p pageid="2764" ns="0" title="Baustelle: Unelastischer Stoß GK2" />
      <p pageid="2045" ns="0" title="Baustelle: Ursache von Bewegung GK2" />
      <p pageid="3303" ns="0" title="Baustelle 6a 2012/13" />
    </allpages>
  </query>
</api>