This specification defines a transport neutral way to address Web services and messages, which facilitates sending messages through networks that include monitors, firewalls or other potential intermediaries. From a developers point of view what is more relevant to understand is that this specification enables other higher-order Web services specifications that provide capabilities like transactions, reliable messaging and security. Many of the WS-* set of specifications have in fact already committed to using WS-Addressing, so its submission to the W3C for standardization is an important milestone. The W3C is the most logical place for this work to take place as that organization deals with many of the related specifications (HTTP, URI, SOAP), particularly at the foundational level where this spec can clearly be seen as residing.
Now Im going to head you off at the pass and answer a couple of questions Im sure youll have if you follow this space. There is a competing specification called WS-MessageDelivery (WS-MD) that was submitted to the W3C earlier this year. WS-A was first published in March of 2003 and did not make use of this or any other specification. Seeing similar specs published or submitted is a pretty normal part of the standardization process so its common to see things like this happen. Now that both specs are at the W3C, when a work group gets chartered hopefully you will see all of the companies come together around a single specification in the open process there.
Now I also mentioned reliable messaging above as utilizing WS-A, that is true for the WS-ReliableMessaging specification that has been published as part of the WS-* set of specs. There is another specification called WS-Reliability underway at OASIS that does not use WS-A. To understand why, it is best to review the materials of the TC that produced the specification, particularly their mail archives. Hopefully the submission to the W3C of WS-A will increase adoption of it elsewhere.
So why did I lead this off with that this sets the stage for the next generation of Web services? Specifically because so many of the WS-* specs I mentioned make us of WS-A that until it is standardized, it makes sense that they cant be either. Now many of these specs are still being worked on and are not yet ready to be submitted for standardization and you should not read too much into just one spec being submitted. Still, this is an important core specification for most of the second generation Web services specifications and its submission to the W3C is an important milestone.
Hopefully someday soon well be able to have some product announcements around this, for now Ill say as an author company we are committed to the adoption of this specification. More later.