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="poll" />
  </query-continue>
  <query>
    <pages>
      <page pageid="778" ns="0" title="BOOTP Client" />
      <page pageid="780" ns="0" title="DHCP Client" />
      <page pageid="685" ns="0" title="DHCPv6 Client" />
      <page pageid="1089" ns="0" title="Dynamic DNS Update" />
      <page pageid="1194" ns="0" title="Extensible Authentication Protocol (EAP)" />
      <page pageid="975" ns="0" title="Multicast Listener Discovery" />
      <page pageid="977" ns="0" title="Multicast Listener Discovery version 2" />
      <page pageid="1163" ns="0" title="Simple Network Time Protocol" />
      <page pageid="950" ns="0" title="Stream Control Transmission Protocol" />
      <page pageid="1180" ns="0" title="Struct:ttTimeCal" />
    </pages>
  </query>
</api>