WS-CDL becomes a W3C CR

, Nov 12, 2005

The Web Services Choreography Description Language Version 1.0 has achieved Candidate Recommendation status.

In case you’re wondering about the relationship to WS-BPEL, here’s a nice quote from the WG’s co-chair, Pi4 Technology’s Steve Ross-Talbot:

Any real business transaction isn’t just one function call, it’s a sequence of function calls and it may be lots of things in parallel between different services that occur. BPEL is about ‘how do I construct Web services out of existing Web services.’ In other words, BPEL is about the orchestration of existing services to yield another service.

Choreography is completely complementary to that. WS-CDL is an unambiguous way of describing the relationships between the services in a peer-to-peer collaboration without necessitating any orchestration at all. That’s very important because if my business and your business are talking together, I can guarantee you that neither of us would accept orchestrating the other’s services. […] In any dance, however, you never see somebody on stage telling the dancers what to do. The dancers have a choreography description. I know this because my daughter’s a dancer. They learn their dance and they learn the ‘touch points’ where they interact with others, the same way you do in a choreography description.