JTOpen contains most of the source code of the popular product, IBM Toolbox for Java (formerly AS/400 Toolbox for Java), and any code contributed from the JTOpen community.

The JTOpen CVS repository contains the most up-to-date version of the JTOpen source code, demos, and contributions. All JTOpen core team members and select JTOpen contributors have read-write access to CVS and WebCVS. The community at-large has read access through the WebCVS interface, and also via anonymous CVS login using the CVSROOT :pserver:anonymous@jt400.cvs.sourceforge.net:/cvsroot/jt400 and no password (or "" in a script or XML file). Note: CVS is a system that lets groups of people work simultaneously on different groups of files. CERN has a Web site with general information on CVS, as does cyclic.com.

For convenience, the latest JTOpen source and javadoc may be downloaded from the JTOpen downloads page. The files in the CVS repository will likely be newer than the files contained in the released zip.

To build the source, see the Apache Ant build.xml. Also see the README for more details.