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="Best_Laid_Plans_(Usagi_Tsukino)" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="2375" ns="0" title="BSSM Plots" />
      <p pageid="2024" ns="0" title="Bad Omens (Eclipse, Kyubey)" />
      <p pageid="2646" ns="0" title="Bad Reputation (Makoto Kino)" />
      <p pageid="1986" ns="0" title="Bad Tidings (Eclipse, Kyubey)" />
      <p pageid="455" ns="0" title="Beat Defenders" />
      <p pageid="4760" ns="0" title="Beautiful Wearable Memories" />
      <p pageid="6" ns="0" title="Behavior" />
      <p pageid="1269" ns="0" title="Belated Christmas Gifts (Usagi)" />
      <p pageid="1303" ns="0" title="Belated Christmas Magical Girl Pictures (Minako Aino)" />
      <p pageid="4436" ns="0" title="Bellinor Adelram" />
    </allpages>
  </query>
</api>