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>
    <allredirects garcontinue="BestPractices/Coding_Guidelines|1663" />
  </query-continue>
  <query>
    <pages>
      <page pageid="291" ns="0" title="BGP/PCEP protocol library" />
      <page pageid="506" ns="0" title="BGP-LS/PCEP" />
      <page pageid="773" ns="0" title="General Style Guidelines" />
      <page pageid="894" ns="0" title="BGP-LS/PCEP:Release Notes 2013" />
      <page pageid="902" ns="0" title="BGP LS PCEP:Release Notes 2013" />
      <page pageid="907" ns="0" title="BGP-LS/PCEP:Release Plan 2013" />
      <page pageid="1937" ns="0" title="TCPMD5:Helium User Guide" />
      <page pageid="2927" ns="0" title="BGP Stress Testing With An Internet Feed" />
      <page pageid="3680" ns="0" title="BGP LS PCEP:Restconf" />
      <page pageid="3950" ns="0" title="BGP LS PCEP:BerylliumHow-To&#039;s/Tutorials" />
    </pages>
  </query>
</api>