Development environment designed to create applications in Java language. Its main purpose is to learn the language (and fundamentals of object-oriented programming in general) and to create simple programs. The main advantage is the graphical representation of the created classes, so that you can easily see the structure of the program.

A very convenient interface allows, among other things, for any operation on classes, independent creation of objects and operations on their methods. The possibilities of the environment can be extended by means of plug-ins. BlueJ is written in Java, making it available on most operating systems.