YAWL

YAWL (Yet Another Workflow Language), an open source workflow language/management system, is based on a rigorous analysis of existing workflow management systems and workflow languages. Unlike traditional systems it provides direct support for all of the workflow patterns (http://www.workflowpatterns.com). YAWL supports the control-flow perspective, the data perspective, and is able to interact with web services declared in WSDL. It is based on a distributed, web-friendly infrastructure.