BlueJ is a simple IDE ideal for teaching the Java programming language and concepts. The
BlueJ environment was developed as part of a university research project about teaching object-orientation to   beginners.The system is being developed and maintained by a joint research group at Deakin University, Melbourne, Australia, and the University of Kent in Canterbury, UK.
The project is supported by Sun Microsystems.

                            BlueJ is implemented in Java, and regularly being tested on Solaris, Linux, Macintosh, and various Windows versions. It should run on all platforms supporting a recent Java virtual machine.