Open source software, while not synonymous with Java, may often be seamlessly integrated with Java code to produce a versatile synthesis that makes developers’ lives much easier. In recent years, developers have taken some open source dynamic languages, commonly referred to as “scripting languages,” and adapted them to the more mainstream Java platform. This allows the new hybrid language to maintain its scripting qualities, while being fully utilized by a Java program. Three of the most prominent open source/Java languages are JRuby, a Java implementation of Ruby; Jython, a Java implementation of Python; and Groovy, an object-oriented programming language for the Java platform.

JRuby, Jython, and Groovy
Before I go into my thoughts on JRuby, Jython or Groovy, let me provide a quick background on myself. I have been using Java since 1996 (it was first released in 1995). I am a Sun-certified Java Architect and have significant Java experience. Moreover, I have spoken at JavaOne a handful of times and will be speaking there again in 2008 on JRuby and Groovy. I have worked with JRuby and Groovy extensively – in fact, at OpenLogic, we used Groovy to build OpenLogic Enterprise, a technology platform that enables businesses to deploy, manage, and control commercial-grade open source infrastructure. We had more than 100,000 lines of Groovy code deployed in the product. We also wrote OSS Discovery, a tool enterprises use to find up to 900 of the most commonly used Java-based development tools, libraries, and server applications in JRuby.

In my experiences, dynamic scripting languages make it easier to write code in many situations. Scripting languages are much more human friendly than, say, C++. They lack all of that meticulous syntax. With dynamic languages, I am freer to do what I want – I can proceed without thinking as much about the nuts and bolts that go into the code. The fact that Microsoft is also getting involved with IronPython and IronRuby for their .NET framework only goes to show that these dynamic languages are significant and valuable. It validates the idea of incorporating dynamic languages – they are here to stay.

In my view, the fact that some scripting languages are based on the Java platform makes them better. They enjoy all the benefits of scripting languages like Ruby and Python, but also provide a very intimate bi-directional interface with Java. They present the developer with the ability to code, test, and debug quickly and efficiently while also harnessing the abilities of the Java platform. Another plus of Java-powered dynamic languages is their ability to leverage thousands of open source libraries written in either their “native” language or in Java. JRuby, Jython, and Groovy incorporate all of these goodies into nice, neat packages.

JRuby allows the embedding of the Ruby interpreter into any Java application with full two-way access between the Java and Ruby code. As such a fusion, it maintains the scripting qualities of Ruby while being tightly integrated with Java, and can be called directly from Java programs. Jython provides similar capabilities around Python. Groovy, unlike JRuby and Jython, is not derived from a foreign language. Rather, it’s loosely based on features from Ruby, Python, Smalltalk, and other languages, but designed from the ground up by Java developers for Java developers. Needless to say, it works well with other Java code and libraries, but is also a powerful scripting language in its own right.