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>
    <search>
      <p ns="0" title="Projets:Perso:2014:PS-PCR" snippet="... (Peltier always powered), 0.0 &lt;span class=&#039;searchmatch&#039;&gt;meaning&lt;/span&gt; zero power (device always off), 0.2 &lt;span class=&#039;searchmatch&#039;&gt;meaning&lt;/span&gt; 20% power (Peltier on 20% of the time, and off 80% of the time) for example&#10;" size="20049" wordcount="2979" timestamp="2014-05-15T13:05:39Z" />
    </search>
  </query>
</api>