This article describes how one would download the sources.
Get the code
Ecopath6: ?https://sources.ecopath.org:8443/svn/Ecopath/trunk/Ecopath6
Ecopath5: ?https://sources.ecopath.org:8443/svn/Ecopath/trunk/Ecopath5
Click OK and enter your username and password
A WinCVS alternative to SVN would be ?RapidSVN A Visual Studio Integration to SVN would be ?ankhsvn.