BPEL

I really think that people are speaking about BPEL without knowing what it is exactly. So here is a good definition that comes from a Cape Clear doc.
Business Process Execution Language for Web Services (BPEL4WS, or BPEL) is an XML Schema-based standard for defining process flows. It enables the composition of multiple synchronous and asynchronous Web services into an end-to-end business flow.
A BPEL script is an XML document that conforms to the BPEL schema. The BPEL script is interpreted at runtime by a BPEL processor that identifies keywords or activities and executes them as defined in the BPEL script.
BPEL is a programming language. Its programming statements enable developers to build robust processes that can:

• Communicate by exchanging messages with other Web services using receive, reply, and invoke activities.
• Control execution flow using while, switch, sequence, pick, flow
• Handle faults that can occur during processing using catch and catchall fault handlers.
• Model event-driven programming using onMessage and onAlarm event handlers.
• Roll back transactions using compensation handlers.