JAPI is a collection of Java libraries that help with various tasks like argument parsing, i18n/l10n, creating gui applications, as well as tools that demonstrate this.
The only -complete- XUL/embedded scripting solution for Java. JFCML supports not only AWT and Swing; but any class accessible to Java's ClassLoader. Also, most major scripting languages, including JavaScript, BeanShell, Jython, Jacl (Tcl), JRuby, more.
The intention of Interlingual is to build a localization tool with full support for the XLIFF format starting with an intuitive and powerful XLIFF editor.