Is Ruby the new Java? (live on stage)

Twice a year the Dutch Java User Group organizes a mini conference with sessions about Java, JEE, and everything related. In spring this day is called J-Spring (which has nothing to do with the Spring framework), in fall it’s called J-Fall. While preparing for RubyEnRails 2006 I thought it would be a good idea to enter a paper for the J-Spring, for an introductory session called Is Ruby The New Java?. I was a bit surprised when my paper was accepted, and even more surprised last Thursday (J-Spring day) about how many Java people showed an interest for my session: I got the big conference hall (and it really does look big when you climb the stage), filled with maybe some 200 people. Even though I got the usual nervous questions about things like duck typing and performance, I had the impression that overall, people really liked what they saw. Apparently Ruby and Rails are hot in Java land.

And likewise, Java is hot in Ruby and Rails land; allbeit with a slightly different angle. I’m talking about the JRuby project, an interface to Java allowing Ruby code to run under a Java Virtual Machine. JRuby’s ‘holy grail’ being to be able to run Rails applications in a Java application server. At this year’s JavaOne, JRuby lead developers Charles Nutter and Tom Enebo were able to show a working Rails application running under Tomcat. In spite of their help and a lot of emails, I did not manage to reproduce their setup for a demo at J-Spring. Instead, I showed how easy it is to call an EJB from Ruby, as well as a Rails application based not on a database but on a Java web service.

You might wonder what’s the use of such an interface to Java. Like I said in my J-Spring presentation, I believe it offers some great possibilities for the future of Ruby and Rails. Once Rails runs on the JVM, it becomes that much easier to use Rails within established enterprisey Java environments. For that to happen, Java developers working within those environments need to be convinced of Ruby and Rails’ added value. And so I hope that my presentation has helped to convert some of those Java developers to Java developers-who-want-to-develop-with-Rails.

If you’re interested you can download my presentation here.

2006-06-21. 3 responses.


  1. I don’t get it. Why is Ruby so much preferred for Java developers? There are so many scripting languages available many run right within the JRE and some compile down to bytecode and play like normal Java classes. Why Ruby? I have nothing against Ruby I just don’t see why so many Java developers are promoting it over Java?

  2. Could you give a example of how to base rails on a Java web service?

  3. @Jeroen: the Rails app that was used for the web service demo can be downloaded from