Griffon is a desktop/RIA framework inspired by Grails. As such it allows you to build applications quickly by using sound conventions, a common application structure and automated tasks. Similar to Grails, Griffon uses the Groovy programming language as a glue between artifacts (Model, View, Controller), however you can mix other JVM languages by installing additional plugins. Such plugins are : Clojure, Scala and JavaFX.
Griffon applications rely on a Swing-based DSL for building the UI. The DSL is backed up by SwingBuilder but can also be extended by means of plugins. Recently Griffon received support for additional UI technologies: SWT, Pivot, Gtk and JavaFX.
Why should you use it you ask, well mainly because it's fun. Programming in Swing has always been a pain. Many times developers decide to us ea declarative option (usually based on XML) to externalize how UIs are built. XML brings its own set of problems. The Groovy DSL allows you to build the UI in a declarative way and have it be compiled too. Lessons learned from the Grails framework and community are also incorporated into Griffon.
Will it get a following such that it will stick around? we certainly hope so.There have been a few companies that have put it to the test already, mostly for internal app development at this point. We're confident the framework we'll see wider adoption in the coming months.
I have done Swing development in the past, but found a cool pattern to follow, that it was actually the way I like to code my UIs. I never liked HTML for the web. Anyway, I never understood why some people went the XML route for their UIs when once you get Swing, it is very elegant and nice to code. But I do understand how a lot of people don't like to code Swing.