BPEL4WS (Business Process Execution Language For Web Services) is a web service orchestration language promoted by IBM, Microsoft and BEA. BPEL4WS is the successor to IBM’s WSFL and Microsoft’s Xlang.

BPEL4WS is an XML based language for describing interaction between services on a network. The interactions take place via web services. BPEL4WS has facilities for sequencing commands, looping, conditional jumping, launching asynchronous and synchronous operations, message correlation and more.

BPEL4WS scripts are run inside of an orchestration engine, such as ChoreoServer.