Josef is stored at sourceforge, in an svn repository. To get a copy, you have several options, each explained below. If you are a windows user, you may want to get the Tortoise SVN for windows client software.
After you got a copy of josef you should be able to build josef.
Assuming you have svn client installed, you can anonymously checkout a copy using the command:
svn checkout http://svn.code.sf.net/p/josef/svncode/trunk/josef josef.
This command checks out josef's trunk and creates a new josef directory in your current directory,
before checking out the source files.
Note: This option won't allow you to commit changes.
To check put jpsef as a developer, allowing you to commit changes, use this url: https://svn.code.sf.net/p/josef/svncode/trunk. To get the core module only, simply use: https://svn.code.sf.net/p/josef/svncode/trunk/josef/josef-core
