W3C and WS-I
Of all the various organizations and vendors involved in proposals for Web services standards, only two are taking a comprehensive view of the technology: W3C and WS-I. W3C is developing a comprehensive Web services architecture and recommended versions of specifications for SOAP and WSDL, whereas WS-I is developing a suite of conformance requirements and tests for XML Schema, SOAP, WSDL, and UDDI.
The W3C Web Services Activity includes an overall Coordination Group and three Working Groups: Web Services Architecture, XML Protocols, and Web Services Description. The Coordination Group comprises the chairs of the three Working Groups and a W3C staff member. W3C also sponsors five additional activities, including those that work on XML, HTML, security, privacy, multimedia, and so on. The W3C is founded and run by the inventor of the Web, Tim Berners-Lee, and has an excellent track record for gaining widespread adoption for its "recommendations," many of which achieve the status of defacto standards.
The WS-I charter focuses entirely on Web services. WS-I was founded in February 2002, and does not yet have a track record with regard to gaining widespread adoption of its work, although their membership has quickly grown to more than 100. A Board of Directors whose membership currently includes Accenture, BEA, Fujitsu, HP, IBM, Intel, Microsoft, Oracle, and SAP runs WS-I. A current notable absence is Sun Microsystems.
WS-I recently established three working groups: Basic Web Services Profile, Sample Applications, and Test Materials and Tools. The working groups are fundamentally intended to produce a common interpretation of the basic Web services specifications that all vendors agree to implement (specifications such as these typically have optional parts and parts subject to interpretation), and enforce that agreement through testing. The sample application group is developing use cases that validate the profile and testing initiatives.
The relationship of W3C and WS-I seems straightforward enough on the surface: One body produces specifications, and the other defines and certifies conformance to them. But the problem is that WS-I is trying to hit a moving target: Both SOAP and WSDL are under revision at the W3C, and it's unclear whether profiles based on existing versions of these specifications will be helpful or required after new versions are published. Yet waiting for W3C to produce standardized versions of SOAP and WSDL is frustrating for a vendor community interested in developing Web services conformant product.
Furthermore, W3C itself is somewhat divided over the Web services question, in particular regarding the relationship of Web services metadata to the Semantic Web Activity. The semantic Web is the term used to describe the future of the Web once it's based on data rather than text. This vision is not necessarily at odds with Web services' future direction, but no one is really sure, and W3C staff and members are deeply divided on the question of which of the two activities is more important in the near term.