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>
    <alllinks galcontinue="執筆規約|440" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="メインページ" />
      <page pageid="234" ns="700" title="パブリック:ご意見" />
      <page pageid="244" ns="0" title="新規ページ作成" />
      <page pageid="261" ns="12" title="ヘルプ:執筆の手引き" />
      <page pageid="415" ns="501" title="固定項目 議論:シンクロ攻撃" />
      <page pageid="448" ns="12" title="ヘルプ:ページの作成方法" />
      <page pageid="449" ns="0" title="執筆規約" />
    </pages>
  </query>
</api>