CVS is an old system for managing code. In order to access a CVS repository, you must install a CVS client.
On Nov 30, SourceForge will limit CVS support to readonly access. For more information see our blog post about decommissioning CVS commit support. If you are a project admin, you can convert your repository to SVN or Git with these instructions.
This CVS repository can be checked out through anonymous (pserver) CVS with the following commands. The module you wish to check out must be specified as the modulename. See the names of the modules in this repository.
cvs -z3 -d:pserver:email@example.com:/cvsroot/py2exe co -P modulename