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>
    <allredirects>
      <r ns="0" title="Davis Vantage Vue" />
      <r ns="0" title="FAQ WX" />
      <r ns="0" title="FAQ WeeWX" />
      <r ns="0" title="Software webcam" />
      <r ns="0" title="Visual Start Meteoclimatic" />
      <r ns="0" title="WDconsole RPI" />
      <r ns="0" title="¿Donde puedo localizar los driver del datalogger para Windows?" />
    </allredirects>
  </query>
</api>