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"?>
    <links plcontinue="1|0|Bioinformatics" />
      <page pageid="1" ns="0" title="Main Page">
          <pl ns="0" title="Agency for Healthcare Research and Quality (AHRQ)" />
          <pl ns="0" title="Aggregated data" />
          <pl ns="0" title="American College of Emergency Physicians: InnovatED" />
          <pl ns="0" title="Ancillary Clinical Information Systems" />
          <pl ns="0" title="Anesthesia Information Management Systems (AIMS)" />
          <pl ns="0" title="Assistant Secretary for Planning &amp; Evaluation" />
          <pl ns="0" title="Automated Clinical Decision Support (CDS) using Pattern Recognition/Temporal Relationships" />
          <pl ns="0" title="Barcode medication administration" />
          <pl ns="0" title="Big Data to Knowledge (BD2K)" />
          <pl ns="0" title="BioBanking" />