STANDARDS GOVERNANCE AND INTEROPERABILITY

As highlighted throughout this chapter, the agreement on Web services standards has been a key contribution to the rapid evolution and adoption of Web services. Looking back to the early releases of XML and SOAP, the W3C has played a pivotal role in governance of Web services standards, but since late 2001, OASIS has played an increasingly visible role in the Web services standards space. Perhaps we are beginning to see a shift in the balance of power around Web services standards? If so, what does this mean for organizations that are using Web services today and in the near future?

W3C and OASIS

Reviewing the Web services standards discussed in this chapter, referenced the W3C and OASIS on numerous occasions. These two standards organizations are very much at the epicenter of the evolving and emerging Web services standards. As yet there has not been a clear demarcation line drawn between the roles and responsibilities of these two organizations, but there could well be an impending struggle for dominance and ownership of Web services standards on the horizon.

Some key differences exist between the approaches that the W3C and OASIS have taken toward defining and publishing standards that will undoubtedly influence how IBM, Microsoft, BEA systems, and Sun Microsystems, among others choose to work with these standards organizations going forward. Figure 2.13 highlights fundamental differences between the W3C and OASIS.

Figure 2.13: W3C and OASIS approach to governance.

Of the three evolving standards at the core of Web services (specifically SOAP, WSDL, and UDDI), two are governed by the W3C and one by OASIS. As the boundaries of Web services capabilities are pushed, it is unclear if emerging standards will be submitted to the W3C or to OASIS. Given observations regarding time to market and intellectual property, it is possible that OASIS will be favored by the likes of Microsoft, IBM, BEA Systems, and so on—but only time will tell where the demarcation line will fall between the W3C and OASIS.

Web Service Interoperability

Recently a new standards organization has appeared on the Web services scene. The Web Services Interoperability (WS-I) organization was jointly launched by IBM, Microsoft, BEA Systems, Fujitsu, Hewlett-Packard, Intel, Oracle, and 46 other vendors on February 6, 2002.

The WS-I was formed to help organizations working with Web services to establish which version of Web services standards to work with. The goal is to ensure that Web services developed on different platforms, using different development tools, will interoperate seamlessly. With this goal in mind, the WS-I’s charter is as follows:

“. . . promote Web services interoperability across platforms, operating systems, and programming languages. The organization works across the industry and standards organizations to respond to customer needs by providing guidance, best practices, and resources for developing Web services solutions.” ^[8]

The promise of greater interoperability is central to the mainstream adoption of Web services, but the plethora of standards and the availability of tools that implement various versions of these standards may potentially to impede this goal. For example, a firm may have developed services using tools that create a WSDL version 1.1 services description, while another system is looking for service descriptions conforming to WSDL version 1.0. As WSDL version 1.1 implements an extended instruction set it is quite possible that the services on these systems will not interoperate as intended.

To tackle this type of interoperability challenge the WS-I has introduced the concept of Web services profiles. The WS-I defines a profile as:

“. . . a named group of Web services specifications at specific version levels, along with conventions about how they work together.” ^[9]

Further, the WS-I has stated that it will:

“. . . develop a core collection of profiles that support interoperability for general purpose Web services functionality.” ^[10]

To date the WS-I has defined a single profile, this being the basic Web services profile. Figure 2.14 illustrates the four standards and the associated versions that together form the basic profile.

Figure 2.14: WS-Basic Web services standards.

Additional profiles will be published as new standards gain acceptance and existing standards are updated to newer versions. WS-I members may self-certify that their software conforms to a specific profile, and it is initially expected that self-certification will be further policed by other WS-I members. It is yet to be determined how effective self-certification will be.

^[8]www.ws-i.org, October 3, 2002, “WS-I Overview,” Version 1.4.

^[9]Ibid.

^[10]Ibid.