WS-Addressing and WS-ReliableMessaging attempt to provide a platform for reliable Web service messaging. However, at this point, WSE provides support for only WS-Addressing. Although WS-Routing and WS-Referral are both supported by the pre-Beta version of WSE 2.0 available when this book went to print and can be used to develop and implement complex and dynamic Web service routing topologies, it seems unlikely that WS-Routing will survive the shakeout that will ultimately decide the protocol stack for Web services. Just to make things a little bit more interesting, a competing reliability specification, named WS-Reliability, is being backed by Oracle, Sun Microsystems, and others. It will be up to the various Web services standards bodies and implementers to determine how message reliability will ultimately be implemented in the enterprise. Stay tuned .