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="Iteaduino Leonardo" snippet="...ns, the processor will reset, breaking the USB connection to the computer (&lt;span class=&#039;searchmatch&#039;&gt;meaning&lt;/span&gt; that the virtual serial / COM port will disappear). After the processor &#10;" size="11326" wordcount="1795" timestamp="2014-06-15T10:16:45Z" />
      <p ns="0" title="Nextion Instruction Set" snippet="| align=&amp;quot;center&amp;quot; style=&amp;quot;background:#f0f0f0;&amp;quot;|&#039;&#039;&#039;&lt;span class=&#039;searchmatch&#039;&gt;Meaning&lt;/span&gt;&#039;&#039;&#039;&#10;| align=&amp;quot;center&amp;quot; style=&amp;quot;background:#f0f0f0;&amp;quot;|&#039;&#039;&#039;&lt;span class=&#039;searchmatch&#039;&gt;Meaning&lt;/span&gt;&#039;&#039;&#039;&#10;" size="40809" wordcount="6105" timestamp="2017-03-31T08:41:24Z" />
      <p ns="0" title="Nextion Editor Quick Start Guide" snippet="Text component is for user to input characters. Click each attribute, its &lt;span class=&#039;searchmatch&#039;&gt;meaning&lt;/span&gt; will be shown on the bottom. &#10;" size="14016" wordcount="2106" timestamp="2017-06-29T09:59:32Z" />
    </search>
  </query>
</api>