BlueJ is a Java development environment, designed and implemented by the BlueJ team at Monash University, Melbourne, Australia and the University of Southern Denmark, Odense. BlueJ is a window based platform for Java Development Environment (JDK). It requires installing JDK 1.3 version or more before installing BlueJ.
BlueJ is basically an IDE (Integrated Development Environment). It includes the following tools: an editor, a debugger and a viewer. BlueJ includes some tools that are helpful for creating Java applications. A tool of BlueJ IDE that is used for finding mistakes in a program is called debugger. In Java, execution begins from main method. Therefore, to execute any other method, first execute main method. BlueJ directly creates jar files or the executable files. Jar files include all files of a given project in a single file so as to provide convenient way to transfer a project from one location to another. Documentation is a vital part of developing project. To document a project properly, a project description should be written with proper comments for all classes and methods.