WS-Addressing and WS-MessageDelivery

Sun in its coninuing truce with Microsoft put the differences aside and joined WS-Addressing - A transport neutral mechanism to address web services. From a web services message flow point of view, WS-Addressing would "enable messaging systems to support message transmission through networks that include processing nodes such as endpoint managers, firewalls, and gateways in a transport-neutral manner." WS-Addressing form a key part, is a building block, of many other WS-* stack, such as WS-Policy, WS-Eventing, WS-RelianbleMessaging etc. Also as per MSDN, WS-Addressing will provide several key foundations for a full SOA (Services Oriented Architecture) implementation.

Looks like WS-MessageDelivery and WS-Addressing have become one camp. WS-Addressing is led by Microsoft/IBM and WS-MessageDelivery by Sun/Oracle. Conspicuously Oracle is not a member as part of WS-Addressing submission to W3C. The other participants of WS-Addressing are SAP, Iona Technologies BEA Systems and Nokia Corp.

One of the biggest difference between WS-Addressing and WS-MD is that WS-Addressing does not have any reference to the WSDL description where as WS-MD ties to WSDL 2.0, such as WS-Ref.

Dave Orcahrd (BEA) has a blog on comparision between WS-Addressing and WS-MessageDeliver.