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>
    <unreviewedpages urstart="Devil&#039;s_Lake_Basin" />
  </query-continue>
  <query>
    <unreviewedpages>
      <p pageid="1244" ns="0" title="Arizona (U.S.)" revid="5837" />
      <p pageid="436" ns="0" title="Browse Cases" revid="9039" />
      <p pageid="1245" ns="0" title="California (U.S.)" revid="5838" />
      <p pageid="1258" ns="0" title="Canada" revid="5875" />
      <p pageid="1268" ns="0" title="Canadian Columbia River Inter-Tribal Fisheries Commission" revid="7423" />
      <p pageid="2320" ns="0" title="Case Study" revid="8617" />
      <p pageid="1246" ns="0" title="Colorado (U.S.)" revid="5839" />
      <p pageid="1265" ns="0" title="Columbia River Basin" revid="5903" />
      <p pageid="1394" ns="0" title="Conflicts over development in India&#039;s Narmada River Basin" revid="7112" />
      <p pageid="2237" ns="0" title="Creative Options and Value Creation to Address Water Security in the Eastern Nile Basin" revid="8373" />
    </unreviewedpages>
  </query>
</api>