The source code is available at sourceforge. Simply use svn and check out the repository, e.g.:

svn checkout https://svn.code.sf.net/p/jvx/code/trunk/java/library jvx-library

The path: trunk/java/library is enough. It's not necessary to checkout the whole trunk.

The directory contains a fully configured Eclipse project. Simply open the JVx project in Eclipse, and everything should be fine.

It's also possible to use another IDE. All dependencies are included in the lib directory, so you shouldn't have any problems. The project has multiple source folders: src, test, test.manual, intern.