The data analysis / GUI building framework JStatCom now offers a Java to R interface based on rJava. The new RStat engine can be used on most platforms and allows to easily use R numerics and graphics in Java projects.
JStatCom is a software framework for builing GUIs for numerical procedures. It can be used to call algorithms written in various languages, like Gauss, Ox, Matlab, via a standard communications interface. Special features are a rich set of graphical components, a flexible event-based data management system, and powerful data import/export facilities. It might also be useful for non GUI applications.