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 Subversion 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 SVN. The community at-large has read access through the Web interface, and also via "svn checkout svn://svn.code.sf.net/p/jt400/svn/ jt400-svn". Note: Subversion is a system that lets groups of people work simultaneously on different groups of files. See the Apache Subversion website for more information. .

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

To build the source, see the Apache Ant build.xml file.
Also see the readme.html for more details.