YAWL is a BPM/Workflow system, based on a concise and powerful modelling language, that handles complex data transformations, and full integration with organizational resources and external Web Services. YAWL offers:

• the most powerful process specification language for capturing control-flow dependencies and resourcing requirements.
• native data handling using XML Schema, XPath and XQuery.
• a formal foundation that makes its specifications unambiguous and allows automated verification.
• a service-oriented architecture that provides an environment that can easily be tuned to specific needs. more...