In the late nineties, Michael Kelling developed an innovative pedagogical language/environment known as Blue, as a part of his Ph.D research. Bluej is a variant of Blue to Java and was first released in 1998. Much to the surprise of many observers, it began to be used around the world as a programming language. It is a highly regarded language, which provides a simple to learn approach for programmers who prefer a purely functional approach over a procedural or object-oriented programming language.
The main difference between BlueJ and Blue is the syntax and semantics of the language. Blue is a low-level, client-server programming language, whereas Bluej is a high-level, server-side scripting language. BlueJ, which is written in Java, provides the ability to create "Hello World" applications without writing a source code (source code is in the source code that produces the output) - a major advantage over Java. Bluej also provides a large number of libraries and tools for web development. As its syntax is identical to that of Java, the majority of people who are familiar with Java do not have to be aware of the various nuances of Blue. As a side benefit, you do not need to be familiar with any Java code to use Blue; indeed, most of the features that the BlueJ framework provides are compatible with that of the popular open source code such as PHP, Perl, Python, and more.
BlueJ, being a simple to learn and use program, was originally developed as a desktop-based application but is gradually being considered as a web application as well. To run BlueJ in your browser, you will need to download and install a small piece of software called BluejServer, which is a part of the BlueJ suite of products. Once the software is installed on your computer, simply start up your browser and visit the official website of Blue. The installation process will take just a few seconds and once the Bluej Extension has been installed, your website will be live!