Our research center has created an open source, visual toolset for the planning, design and prototyping of electronic messages. The primary use for this toolset is to help organizations with complex messaging requirements validate electronic message structures and content before beginning any IT development (generally in the business requirements phase).  Our toolset consists of three elements, a plug-in developed for a commercial UML modeling tool (MagicDraw UML) that a business analyst or consultant would use to model the entire message environment using UML Activity and Class diagrams.  We then load the diagrams to a specially modified workflow engine that gives the users the ability to follow the models based on inter message and business defined rules.  The last part of the toolset is a "centralized client" based on Chiba Xforms that allows multiple users to interact with the various messages via their web browser. The cost benefit is that you can have a fully accurate model validated by all parties before approaching IT for development and testing. All of the modeling output is then stored in standard UML/XML format for future reference.  More technical information, as well as download instructions, can be found on our web site: http://efficient.citi.tudor.lu/