Workflow Modeling

www.yawl-system.com/. Free YAWL tool and documents on workflow modeling.

www.workflowpatterns.com. A compendium of resources on the well-known workflow patterns.

www.pi-workflow.org. Workflow patterns from a pi-calculus viewpoint.

www.oasis-open.org. The home of the BPEL standard.

www.omg.org. The latest information on the BPMN and BPDM standards can be found here.