While some vendors, most notably IBM, say they would like to see everyone agree on a single Web services stack -- the protocols used to define, locate, implement and make Web services interact -- it does not appear likely to happen.
Even advocates of open source Apache Axis 2.0 Web services stack, which is now part of IBM WebSphere, don't expect all the vendors to settle on one standard stack. Paul Fremantle, co-founder and vice president of technology at Open Source Web services startup WSO2, a member the Apache Foundation and an evangelist for Axis, said, "I don't think it will become a standard."
Bradley F. Shimmin, principal analyst of application infrastructure at Current Analysis LLC. agreed that standardization on a single Web services stack is unlikely given competing stacks from different vendors and the heterogeneous environments of most customers. "I don't think that will ever happen. I don't see how it could happen. It's like assuming that software will never get versioned."
As co-chair the OASIS Technical Committee standardizing Web Services Reliable Messaging, Fremantle supports standards, but still sees pluses in the reality that there is no Web services stack standard.
While Axis 2.0 runs on WebSphere, as well as WebLogic from BEA Systems Inc., and Apache's own Tomcat, and has demonstrated interoperability with Microsoft .NET, Fremantle notes that BEA and JBoss, the division of Red Hat Inc., have chosen to develop their own Web services stacks. BEA offers SALT 1.1, a native Tuxedo Web service stack built on an open-standard SOAP implementation. JBossWS is a JAX-WS compliant Web services stack developed to be part of JBoss' Java EE5 support.
"It's nice to have a single stack that runs on WebSphere, Tomcat and WebLogic," Fremantle said, "But there is also value in competition." He argues that having several stacks vying for developers' attention drives all of the competing stacks to get better and better.
In the case of Axis, he said the new Axis 2.0 improves on Axis 1.0. "Axis 1.0 couldn't handle large volumes of data," Fremantle explained. The new Axis 2.0 is demonstrating data transmission speeds that are two-to-10 times faster than its predecessor, he said.
The improved performance may explain why IBM is more fully supporting Axis 2.0 in WebSphere, whereas with Axis 1.0, Fremantle said IBM had to make tweaks to get it to provide commercially viable data transmission.
Jerry Cuomo, IBM WebSphere CTO, explained the evolution this way: "Our Web services stack is built on top of Axis 2. That's with WebSphere 6 with the feature pack we just announced. Our previous Web services stack was a derivative of Axis 1 with some code we built ourselves. This time we're going to try to keep more in sync with the Axis 2 project. So we do have a standards-based stack. You can get the source code and see it."
Cuomo said he would like to see at standard stack, but acknowledged that while Axis 2 is an improvement over Axis 1, it is still "imperfect." But he said that IBM is now committed to working with Apache on upgrades to Axis 2.0, as well as the future development of Axis 3.0.
Concern over whether Axis 3.0 or anything else will ever become a standard Web services stack is not as important in the overall scheme of service-oriented architecture (SOA) as establishing standards for the larger SOA infrastructure, in the opinion of Jason Bloomberg, senior analyst with ZapThink LLC. The Web services stack is something of a bit player in SOA.
"A Web services stack is a rather limited thing," he said. "It's software that supports the Web services standards so you can send and receive SOAP messages and do the UDDI and WSDL stuff. It's a limited thing. And the Web services stacks themselves are reasonably mature. We've been building those for five years or more."