RealJ - Version 3.5 RealJ is a development environment that works with the JavaSoft JDK. FreeJava allows you to edit source code, compile, and run Java applets and applications. It offers complete support for the latest JDK, a class and function browser, full syntax coloring in source windows, and drop-down function menus in source editors. Also, you can double-click compiler errors to go straight to the source code.