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>
    <allfileusages afcontinue="Cloud_affiliation_Almondplus_screen_3.png" />
  </query-continue>
  <query>
    <allfileusages>
      <f ns="6" title="File:Belkin Wemo.jpg" />
      <f ns="6" title="File:Central Motion Sensor.jpg" />
      <f ns="6" title="File:Centralite 3 Series.jpg" />
      <f ns="6" title="File:Climax CO-8ZBS.png" />
      <f ns="6" title="File:Climax LS-1E-G-GZBS.jpg" />
      <f ns="6" title="File:Climax Motion.jpg" />
      <f ns="6" title="File:Climax SD-8SCZBS.jpg" />
      <f ns="6" title="File:Climax pss29.png" />
      <f ns="6" title="File:Cloud affiliation Almondplus screen 1.png" />
      <f ns="6" title="File:Cloud affiliation Almondplus screen 2.png" />
    </allfileusages>
  </query>
</api>