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>
    <pageswithprop pwpcontinue="3749" />
  </query-continue>
  <query>
    <pageswithprop>
      <page pageid="232" ns="0" title="AVerage" value="aVerage" />
      <page pageid="383" ns="0" title="P54 shuttle" value="p54 shuttle" />
      <page pageid="1363" ns="0" title="Xp2 caabaiczw32" value="xp2_caabaiczw32" />
      <page pageid="2196" ns="0" title="X66" value="x66" />
      <page pageid="2570" ns="0" title="P18 bi-block hassler" value="p18 bi-block hassler" />
      <page pageid="3025" ns="0" title="P5760 unit Life cell" value="p5760 unit Life cell" />
      <page pageid="3495" ns="0" title="P690 60P5H2V0 gun" value="p690 60P5H2V0 gun" />
      <page pageid="3497" ns="0" title="P416 60P5H2V0 gun" value="p416 60P5H2V0 gun" />
      <page pageid="3581" ns="0" title="Von Neumann neighbourhood" value="von Neumann neighbourhood" />
      <page pageid="3685" ns="0" title="P110 traffic jam" value="p110 traffic jam" />
    </pageswithprop>
  </query>
</api>