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="De_tre_mostrene" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="10" ns="0" title="Bamse Brakar" />
      <p pageid="11" ns="0" title="Berthe Tuppenhaugs fortellinger" />
      <p pageid="12" ns="0" title="Bjørnen og reven" />
      <p pageid="206" ns="0" title="Chapter 1" />
      <p pageid="208" ns="0" title="Chapter 10" />
      <p pageid="207" ns="0" title="Chapter 2" />
      <p pageid="13" ns="0" title="De syv folene" />
      <p pageid="14" ns="0" title="De tolv villender" />
      <p pageid="15" ns="0" title="De tre bukkene Bruse som skulle gå til seters og gjøre seg fete" />
      <p pageid="16" ns="0" title="De tre kongsdøtre i berget det blå" />
    </allpages>
  </query>
</api>