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="DSP_Plugin" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="44785" ns="0" title="Basic Plugin Guide - Tutorial" />
      <p pageid="44720" ns="0" title="Beginner&#039;s Basic Plugin Guide" />
      <p pageid="209" ns="0" title="Box source code here" />
      <p pageid="224" ns="0" title="Color Editor" />
      <p pageid="347" ns="0" title="Complete JavaScript API technology framework" />
      <p pageid="48588" ns="0" title="Complex Numbers" />
      <p pageid="228" ns="0" title="Creating Classic Skins" />
      <p pageid="67" ns="0" title="Creating Custom Cursors" />
      <p pageid="227" ns="0" title="Creating Modern Skins" />
      <p pageid="226" ns="0" title="Creating a ClassicPro Skin" />
    </allpages>
  </query>
</api>