Get the Sources
You can get the sources in a number of different ways:
Easiest is to download one of the source zip-files from SourceForge . The releases  are supposed to be relatively stable (although of course we are still below version 1.0!); whereas the snapshots  contain newer code that may not have been tested yet.
If you want the latest code, you should use CVS.
The CVS repository can be checked out through anonymous (pserver) CVS with the following instruction set. When prompted for a password for anonymous, simply press the Enter key.
cvs -d:pserver:email@example.com:/cvsroot/es40 login cvs -z3 -d:pserver:firstname.lastname@example.org:/cvsroot/es40 checkout -P es40
This will create a directory called "es40" that contains the sources.