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>
    <protectedtitles ptstart="2009-09-01T18:42:51Z" />
  </query-continue>
  <query>
    <protectedtitles>
      <pt ns="1" title="Talk:Pathloss 5 - Basic program information" timestamp="2011-09-28T16:40:41Z" level="sysop" />
      <pt ns="1" title="Talk:Pathloss 5 - Import links from text file" timestamp="2010-06-10T17:53:33Z" level="sysop" />
      <pt ns="13" title="Help talk:Contents" timestamp="2010-04-14T17:09:07Z" level="sysop" />
      <pt ns="4" title="PathlossWiki:General disclaimer" timestamp="2010-04-14T17:06:27Z" level="sysop" />
      <pt ns="4" title="PathlossWiki:Autoconfirmed users" timestamp="2010-04-06T14:46:46Z" level="sysop" />
      <pt ns="1" title="Talk:SRTM" timestamp="2010-04-06T14:44:35Z" level="sysop" />
      <pt ns="5" title="PathlossWiki talk:General disclaimer" timestamp="2010-03-24T20:08:35Z" level="sysop" />
      <pt ns="3" title="User talk:Chrisg" timestamp="2010-03-24T20:08:02Z" level="sysop" />
      <pt ns="1" title="Talk:Pathloss 4.0 revision history" timestamp="2009-12-02T20:24:43Z" level="sysop" />
      <pt ns="1" title="Talk:Pathloss 5 - Import sites from text file" timestamp="2009-11-10T18:41:40Z" level="sysop" />
    </protectedtitles>
  </query>
</api>