Congratulations to the JRuby team for the release of JRuby 1.0!

I love programming in Java and I also love programming in Ruby, so this project is of particular interest for me as I can write stuff in Ruby and yet leverage / mix it with the amazing amount of Java frameworks and libraries. I see a strong future for the Java platform with new languages establishing themselves as first class citizen. This obviously includes JavaScript, JRuby, but Groovy should not be forgotten. In fact, there are some stuff I would write in Groovy rather than in Ruby via JRuby, especially when it comes to using a library that leverages Java annotations (think the excellent Berkeley DB JPA for example).

I am however more sceptic regarding the vision of picking any Ruby application and running it on JRuby. The project has generated a lot of buzz by making it possible to run Ruby On Rails applications on top of JRuby, and by going as far as to generate what is needed to generate a WAR that you can drop into a Servlets container.

I do understand that this shows how strong JRuby has gotten recently, but I am not personally interested in running a Rails application on top of Java, and I don’t see it becoming the main reason to use it. Instead, I believe that “pure Ruby” applications should keep on being designed for Ruby, and running them using JRuby should just be an option. One should also remind that some libraries / ruby gems require native libraries linking, which is not possible to do with JRuby. By contrast, programmers that would like to write part of their programs in Ruby while leveraging the Java platform, the myriad of libraries and frameworks around here should find in JRuby the enabler that they need.

As a conclusion, I believe that people should not expect more of JRuby than it should be capable of. Specifically, JRuby should not become the “universal Ruby” platform, but rather a Ruby-compliant, efficient, and with seamless Java-integration of the Ruby language and standard library.