Physhun Finite State Machine Framework
Complex processes can often be expressed naturally as state models, and executed in a Finite State Machine. Physhun is an open source framework for modeling, building and executing Finite State Models in J2SE and J2EE environments. Although it is simple, it is also powerful in that it allows processes to be long lived, persistent and transactional. Processes can be purely synchronous, or can be interacted with asynchronously as is common in Workflow processes.

The Physhun framework was originally written by Wazee Group, and was released as an open source project in November of 2005. Wazee Group remains active in the development of the Physhun framework, as well as addons to Physhun like the Physhun XML package. Additionally, Wazee Group offers Physhun Modeler, a graphical editor for Physhun state models, free of charge to users of Physhun.

Related Articles:

TheServerSide.com - Implementing Finite State Machines with Physhun and Spring
This TheServerSide.com article describes the Physhun open source project that implements a finite state machine with a Spring-based framework.  

TheServerSide.com - Putting Physhun To Work
The article was published on TheServerSide.com and describes a monitoring system for complex XML transactions. This solution was the first production deployment of the Physhun open source project.  

JXBeans XML Processing Framework
JXBeans is an XML processing framework that was evolved by Wazee Group team members during an engagement in early 2002. This technology allows developers to develop xml based processes very rapidly. Wazee Group sponsors the JXBeans open source project and has contributed code to the project in the past.