Matt's source code is maintained in a <a href="http://fossil-scm.org/">Fossil</a> repository.  To check out the Matt fossil repository you will need a Fossil client, which can be obtained at:
<ul><li><a href="http://www.fossil-scm.org/download.html">http://www.fossil-scm.org/download.html</a></li></ul>

Checking it out is easy:
   #  <tt>$ fossil clone http://matt.rkeene.org/ matt.fossil</tt>
   #  <tt>$ fossil open matt.fossil</tt>