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>
    <alltransclusions gatcontinue="Button|4973" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1286" ns="0" title="EAC Drive Options" />
      <page pageid="1540" ns="100" title="Foobar2000:Freedb masstagger (foo freedb)" />
      <page pageid="2502" ns="100" title="Foobar2000:Components/Decoding Speed Test (foo benchmark)" />
      <page pageid="3568" ns="100" title="Foobar2000:Properties" />
      <page pageid="3639" ns="100" title="Foobar2000:File Operations (foo fileops)" />
      <page pageid="3828" ns="100" title="Foobar2000:Components/BPM Analyser (foo bpm)" />
      <page pageid="3999" ns="100" title="Foobar2000:Converter" />
      <page pageid="4009" ns="100" title="Foobar2000:How to install a component" />
      <page pageid="4147" ns="100" title="Foobar2000:Components/m-TAGS (foo tags)" />
      <page pageid="4688" ns="10" title="Template:Brokenlink" />
    </pages>
  </query>
</api>