BlueJ

BlueJ is a free integrated development environment for Java, designed for beginners. It is different because it was built for teaching and is free, open-source software.

Features:

• The free Blueroom website offers teaching resources and a place to talk with other educators, and the BlueJ website adds tutorials and reference documentation.
• There is a textbook, "Objects First with Java: A Practical Introduction Using BlueJ", co-written by the developers of BlueJ, which can be a great help to beginners.
• There are extensions available for download to enhance the functionality of the BlueJ software, giving it further capabilities.
• Its simple design shows classes as a diagram and lets you create objects, call their methods and inspect their values; a code pad runs Java expressions directly.

This product is free to download, and available across many platforms.

BlueJ is an excellent program for learning object-oriented programming. It is developed at King's College London with support from Oracle and is released under the GNU GPL version 2 with the Classpath Exception. BlueJ 6 adds Kotlin support next to Java and Stride. Its clear design, scope highlighting and extensions make the program easy to use for both simple and larger student projects.