BPEL, originally called BPEL4WS (Business Process Execution Language for Web Services) is a language for describing Web service orchestration in terms of stateful, long-running interactions consisting of synchronous and asynchronous message exchanges. It supplies a notion of abstract processes to describe externally visible behavior as well as executable processes, which can be run either by some interpreter or by compiling them into some executable form. This article focuses on executable BPEL processes and presents one view on the benefits that BPEL brings to an XML Web service embodiment of SOA principles. BPEL plays an important role in SOA by providing a powerful means by which business logic can be articulated and executed at an abstraction level designed to provide the services needed for integration tasks.