This article proposes specific extensions for WS-BPEL (Business Process Execution Language) to support versioning of processes and partner links. It introduces new activities and extends existing activities, including partner links, invoke, receive, import, and onmessage activities. It proposes version-related extensions to variables and introduces version handlers. The proposed extensions represent a complete solution for process-level and scope-level versioning at development, deployment, and run-time. It also provides means to version applications that consist of several BPEL processes, and to put temporal constraints on versions. The proposed approach has been tested in real-world environment. It solves major challenges in BPEL versioning.