BlueJ

BlueJ
Original author(s)Michael Kölling and John Rosenberg
Developer(s)BlueJ Team
Stable release
5.5.0 / June 3, 2025 (2025-06-03)
Written inJava
Operating systemCross-platform
PlatformJava
Available inMultilingual
TypeIntegrated development environment
LicenseGPL-2.0-or-later with the Classpath exception
Websitebluej.org

BlueJ is an integrated development environment (IDE) for the Java programming language, developed mainly for educational purposes, but also suitable for small-scale software development. It runs with the help of Java Development Kit (JDK).

BlueJ was developed to support the learning and teaching of object-oriented programming, and its design differs from other development environments as a result. The main screen graphically shows the class structure of an application under development (in a UML-like diagram), and objects can be interactively created and tested. This interaction facility, combined with a clean, simple user interface, allows easy experimentation with objects under development. Object-oriented concepts (classes, objects, communication through method calls) are represented visually and in its interaction design in the interface.