JTOpen is the open source version of the IBM Toolbox for Java
licensed program product.  The IBM Toolbox for Java is a library
of Java classes supporting the client/server and internet programming
models to a system running OS/400 or i5/OS. The classes can be used
by Java applets, servlets, and applications to easily access OS/400
and i5/OS data and resources.

The Toolbox does not require additional client support over and
above what is provided by the Java Virtual Machine and TCP/IP.

WWW: http://jt400.sourceforge.net/