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>
    <allimages>
      <img name="D2501ac4b3.jpg" timestamp="2014-12-17T14:37:50Z" url="http://wiki.rpg.ru/images/9/95/D2501ac4b3.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:D2501ac4b3.jpg" ns="6" title="Файл:D2501ac4b3.jpg" />
      <img name="School.jpg" timestamp="2014-02-10T06:54:27Z" url="http://wiki.rpg.ru/images/8/82/School.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:School.jpg" ns="6" title="Файл:School.jpg" />
      <img name="ЗКлого.jpg" timestamp="2014-12-17T11:20:03Z" url="http://wiki.rpg.ru/images/5/5c/%D0%97%D0%9A%D0%BB%D0%BE%D0%B3%D0%BE.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:%D0%97%D0%9A%D0%BB%D0%BE%D0%B3%D0%BE.jpg" ns="6" title="Файл:ЗКлого.jpg" />
      <img name="Клэр_и_Куб.jpg" timestamp="2014-12-17T11:18:02Z" url="http://wiki.rpg.ru/images/c/c1/%D0%9A%D0%BB%D1%8D%D1%80_%D0%B8_%D0%9A%D1%83%D0%B1.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:%D0%9A%D0%BB%D1%8D%D1%80_%D0%B8_%D0%9A%D1%83%D0%B1.jpg" ns="6" title="Файл:Клэр и Куб.jpg" />
      <img name="Премия_Золотой_Куб.jpg" timestamp="2014-12-17T11:06:44Z" url="http://wiki.rpg.ru/images/b/b0/%D0%9F%D1%80%D0%B5%D0%BC%D0%B8%D1%8F_%D0%97%D0%BE%D0%BB%D0%BE%D1%82%D0%BE%D0%B9_%D0%9A%D1%83%D0%B1.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:%D0%9F%D1%80%D0%B5%D0%BC%D0%B8%D1%8F_%D0%97%D0%BE%D0%BB%D0%BE%D1%82%D0%BE%D0%B9_%D0%9A%D1%83%D0%B1.jpg" ns="6" title="Файл:Премия Золотой Куб.jpg" />
      <img name="Яхта_-_карта.jpg" timestamp="2012-07-10T06:48:04Z" url="http://wiki.rpg.ru/images/9/96/%D0%AF%D1%85%D1%82%D0%B0_-_%D0%BA%D0%B0%D1%80%D1%82%D0%B0.jpg" descriptionurl="http://wiki.rpg.ru/index.php/%D0%A4%D0%B0%D0%B9%D0%BB:%D0%AF%D1%85%D1%82%D0%B0_-_%D0%BA%D0%B0%D1%80%D1%82%D0%B0.jpg" ns="6" title="Файл:Яхта - карта.jpg" />
    </allimages>
  </query>
</api>