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 gafcontinue="BUR_rocket.jpg|3705" />
  </query-continue>
  <query>
    <pages>
      <page pageid="30" ns="0" title="Class 1 weapons" />
      <page pageid="676" ns="0" title="BSA Lewis Gun" />
      <page pageid="699" ns="0" title="Class 3 weapons" />
      <page pageid="755" ns="0" title="BMS Milcam HB" />
      <page pageid="2669" ns="0" title="Class 5 Long weapons" />
      <page pageid="2856" ns="0" title="BRR Tactical light crossbow" />
      <page pageid="3781" ns="0" title="List of bayonets" />
      <page pageid="3817" ns="0" title="BM59 bayonet" />
      <page pageid="5834" ns="0" title="BSA Welrod Mk I" />
    </pages>
  </query>
</api>