BPEL

In computer science, the Business Process Execution Language (BPEL) is an XML language to describe business processes. A BPEL program is invoked as a Web service, and it can interact with the external world only by calling Web services. The standard that defines how BPEL is used in Web service transactions is BPEL4WS also known as WS-BPEL. BPEL is designed by IBM and Microsoft, based on their respective work on WSFL and XLANG, which are both superseded by BPEL. In April 2003, BPEL was submitted to OASIS and is now being standardized in the .

The BPEL Language

The BPEL language provides constructs for sequences, loops, conditionals, fault handling and concurrent execution of operations, just like many programming languages.

BPEL Engines

Several BPEL engines have been developed, including:

• IBM BPWS4J is downloadable from the IBM alphaWorks Web site. Just like other alphaWorks software, BPWS4J has the status of emerging technology. IBM has not yet integrated this or another BPEL engine into one of its production-level product, like WebSphere.
• Collaxa BPEL Orchestration server is a complete BPEL engine running on top of a J2EE application server. The upcoming version 2 will include a visual BPEL designer, based on Eclipse.
• OpenStorm ChoreoServer is a BPEL engine running on top of the .NET platform.
• FiveSight PXE is a modular BPEL engine with a focus on reliability and flexibility.
• Active Endpoints ActiveWebflow Server is a complete BPEL engine running on top of a J2EE application server. ActiveWebflow Designer is an Eclipse-based visual BPEL designer.
• Oracle Business Process Execution Server is a BPEL engine running ontop of the Oracle Application Server.
• ActiveBPEL Engine is a comprehensive BPEL runtime environment. Written in Java, ActiveBPEL Engine is available as an open source technology released under the GPL.