W3C Publishes Web Services Choreography Description Language (WS-CDL).
Update 2004-12-29: "Last Call for W3C Web Services Choreography Description Language (WS-CDL)."
An initial Public Working Draft of the Web Services Choreography Description Language Version 1.0 has been released by W3C.
This document, the first in a series of WS-CDL working drafts, has been produced by members of the W3C Web Services Choreography Working Group as part of the Web Services Activity. Editors of the specification are Nickolaos Kavantzas (Oracle), David Burdett (Commerce One), and Greg Ritzinger (Novell).
The WS-CDL XML-based language "describes peer-to-peer collaborations of Web Services participants by defining, from a global viewpoint, their common and complementary observable behavior, where ordered message exchanges result in accomplishing a common business goal. The Web Services Choreography specification is targeted for composing interoperable peer-to-peer collaborations between any type of Web Service participant regardless of the supporting platform or programming model used by the implementation of the hosting environment."
According to the W3C announcement, the Web Services Choreography Description Language is a "necessary complement to end point languages such as BPEL and Java. WS-CDL provides them with the global model they need to ensure that end point behavior — the 'rules of engagement' — is consistent across cooperating services. Business transactions, especially those envisioned by Web services, grow from complex interactions. These interactions can be viewed from a variety of points in the transaction chain, not simply the start or the expected endpoint. Modeling these interactions from a global viewpoint allows software developers to take into account the distributed race conditions (unexpected dependence on the sequence of events) that may exist — in much the same way they exist in non-Web business processes. Choreography provides the set of rules that explains how different components may act together, and in what sequence, giving a flexible systemic view of the process."
