At my company, we are currently developing an open source package called Ruby on Spring that integrates the JRuby dynamic language with the Spring application framework. Ruby on Spring is open source and licensed under the MIT license
The goals of the project are to permit rapid innovation and iteration, full reuse of our existing Spring and Hibernate business logic and objects, and a smooth transition from prototype to production code.
We were inspired by many of the benefits and philosophy of Ruby on Rails, including avoiding configuration files and compilation. Make a change, and you’ll see it immediately. At the same time, if you’re already commited to Spring, the package doesn’t require you to learn a new framework or abandon your existing investment in Spring. The total size of the package is less than a 1000 lines, so it’s small and easily integrated into existing projects.
The key part of the system is a Spring controller that instantiates a JRuby script engine and executes a JRuby script to define the controller and the model. The view is provided by a standard JSP file. If the JRuby controller is replaced by a Java one, the view can be used as-is with no changes.