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>
    <querypage qpoffset="10" />
  </query-continue>
  <query>
    <querypage name="Ancientpages">
      <results>
        <page value="20130203002909" timestamp="2013-02-03T00:29:09Z" ns="0" title="Projekt LEM" />
        <page value="20130205170911" timestamp="2013-02-05T17:09:11Z" ns="0" title="Otwarte problemy" />
        <page value="20130206113023" timestamp="2013-02-06T11:30:23Z" ns="0" title="Porównanie języków programowania obiektowego" />
        <page value="20130206171539" timestamp="2013-02-06T17:15:39Z" ns="0" title="AndrzejSalwicki/piaskownica" />
        <page value="20130213145021" timestamp="2013-02-13T14:50:21Z" ns="0" title="Algorytm Winograda" />
        <page value="20130307093549" timestamp="2013-03-07T09:35:49Z" ns="0" title="Niestandardowy model liczb naturalnych" />
        <page value="20130313183430" timestamp="2013-03-13T18:34:30Z" ns="0" title="SpecVer:O projekcie" />
        <page value="20130314083241" timestamp="2013-03-14T08:32:41Z" ns="0" title="Proof-checker" />
        <page value="20130331194836" timestamp="2013-03-31T19:48:36Z" ns="0" title="Loglan dla innych języków programowania" />
        <page value="20130403134136" timestamp="2013-04-03T13:41:36Z" ns="0" title="Edytor dowodów" />
      </results>
    </querypage>
  </query>
</api>