One of the mission statements of Multiverse is to create a STM that can be used inside any JVM based language. We already have Scala integration available (although it needs some care) and since yesterday we also have someone responsible for integrating Multiverse with JRuby (welcome aboard Sai Venkat).
But it would be cool if we can add Groovy integration in the 0.5 release (in a week) so that it seamlessly integrates with Groovy. So we are looking for someone with Groovy experience, wants to experiment with STM technology and work on an Open Source project.
If you are interested, send a mail to alarmnummer at gmail dot com.