W3C has issued a Call for Participation in the Workshop on Frameworks for Semantics in Web Services, to be held June 9-10, 2005 at the Digital Enterprise Research Institute (DERI), Innsbruck, Austria.

The workshop objective is to have participants discuss the features of a "comprehensive and expressive framework for describing all aspects of Web services, envisioning more powerful tools and fuller automation using Semantic Web technologies such as RDF and OWL. Output of the workshop will provide advice to W3C on possible future work in the area, and in particular the creation of a Working Group."

Design of the Workshop on Frameworks for Semantics in Web Services builds upon results of an October 2004 W3C Workshop on Constraints and Capabilities for Web Services. That workshop elicited proposals for Semantic Web technologies in the light of requirements for expressing policies for Web Services. W3C now aim at "looking into a generic extensible framework based on Semantic Web technologies, to support longer-term objectives, while continuing to develop immediate solutions for the most pressing Web Services requirements. The OWL-S submission has already demonstrated interest in this approach. Integration to the Web Services stack, and also in the Web architecture, should be key properties of such a framework."

The Call for Participation notes that there are many potential relationships to existing Semantic Web efforts as well as to existing Web Services development efforts.

Participants are encouraged to discuss the the relationship of these areas to the workshop topic. For example, RDF and OWL are foundational Semantic Web background technologies; SOAP and WSDL are core Web Services background technologies. Other relationships include eegistries, taxonomies, and search mechanisms (e.g., UDDI), rule languages such as SWRL, ontologies for Web Services (e.g., OWL-S, WSMO), Web Services Choreography (e.g., WS-CDL) and business process specifications (e.g., BPEL4WS).

Position papers, especially those containing use cases and examples, are solicited from interested parties. Topics may include any of the following, or related perspectives: "(1) Relationship to existing technology efforts, with exploration of benefits and drawbacks to leveraging them; (2) Ontologies for Semantic Web Services; (3) Specific problem domains such as versioning, security, management, internationalization; (4) Integration in the Web Services Architecture, in particular description and composition of Web Services; (5) Location of semantics in Web Services Description; (6) Reasoning about Web Services, for example search, discovery, choice, and what kind of logic could be needed/expressed; (7) Automating tasks based on semantic descriptions; (8) Integration in the Web Architecture, in particular the representation of resources and interaction."

This W3C Workshop on Frameworks for Semantics in Web Services is open to public; prospective attendees are required to submit position papers in order to participate. Position papers should be submitted in valid XHTML/HTML by April 22, 2005. The paper submissions will be refereed, and the workshop will be limited to 80 participants.

As is customary for W3C workshops, the accepted position papers will be made available from the public W3C workshop web site. This event is the latest in a series of workshops and symposia organized by the W3C Team "to promote early involvement in the development of W3C Activities from Members and the public. The goal of a workshop is usually either to convene experts and other interested parties for an exchange of ideas about a technology or policy, or to address the pressing concerns of W3C Members."

Workshop Background and Motivation

"Web Services standards, under development in the W3C Web Services Activity and other organizations, make up an integrated technology stack that Web applications developers can rely on to ensure interoperability. From the beginning, some research has been conducted to meet particular needs in this area, such as registering resources or services, discovering resources or services on the Web, composing a service by using several other services, etc. The early solutions consist of using Web agents, often using pre-defined directories, sometimes simply crawling the Web.

In parallel, starting from the need for metadata in resources, the W3C Semantic Web Activity has developed the initial building blocks of the Semantic Web technologies: the Resource Description Framework (RDF) and the Web Ontology Language (OWL). The W3C Semantic Web Services Interest Group has shown a strong interest in having more integrated semantics inside the Web Services stack, and also provides evidence of a rich variety of research proceeding in this area. This work aims towards the general objective of a more comprehensive, more expressive framework for describing all aspects of services, which can enable more powerful tools and fuller automation of a broad range of Web services activities.

Recently, during the Constraints and Capabilities Workshop, proposals including Semantic Web technologies have already been discussed, in the light of requirements for expressing policies for Web Services. We now aim at looking into a generic extensible framework based on Semantic Web technologies, to support longer-term objectives, while continuing to develop immediate solutions for the most pressing Web Services requirements. The OWL-S submission has already demonstrated interest in this approach. Integration to the Web Services stack, and also in the Web architecture, should be key properties of such a framework.

The intent of the workshop on Frameworks for Semantics in Web Services is to provide advice to W3C on possible future work in the area, in particular the creation of a Working Group..." [from the Call for Participation]

About the W3C Web Services Activity

"Work on Web services is being managed as part of W3C's Architecture Domain. The goal of the Web Services Activity is to design a set of technologies that fit in the Web's architecture, in order to lead Web services to their full potential...

Similar to programmatic interfaces available since the early days of the World Wide Web via HTML forms, programs are now accessible by exchanging XML data through a Web interface by using SOAP Version 1.2, the XML-based messaging framework produced by the XML Protocol Working Group. Web services provide a standard means of interoperating between different software applications, running on a variety of platforms and/or frameworks.

The power of Web services, in addition to their great interoperability and extensibility thanks to the use of XML, is that they can then be combined in a loosely coupled way in order to achieve complex operations. Programs providing simple services can interact with each other in order to deliver sophisticated added-value services.

The W3C Web Services Activity is composed of four Working Groups and one Interest Group, coordinated by a Coordination Group. All groups conduct their technical discussions on public mailing lists, provide proceedings of their meetings publicly, and make editors' copies of their documents available from their home pages. All Working Groups work on a Royalty-Free basis. The Activity is chartered through 28 February 2006.

Architectural Framework: The rapid development of new Web services technologies raised questions about a common model for Web services and its integration within the World Wide Web's architecture. The Web Services Architecture Working Group was chartered in January 2002 for two years with producing an architecture document which explains how all the pieces fit together. In February 2004, the group completed its work and closed with the publication of the Web Services Architecture Working Group Note and several supporting documents...

Messaging Framework (XML Protocol Working Group): The information exchanged with a Web service may be of a complex nature. For example, one may need to transmit a purchase order accompanied by a PNG image, with certain parts encrypted, and have the document signed to guarantee its authenticity and integrity. The receiving agent needs to be able to make sense of the information after checking its authenticity and decrypting the relevant parts. Created in September 2000, the XML Protocol Working Group was originally chartered to develop an XML-based messaging framework.

Addressing Mechanism (Web Services Addressing Working Group): Applications may need to embed in a message some information to direct the information and subsequent replies and faults, particularly in asynchronous interactions. The Web Services Addressing Working Group, started in October 2004, is develop such a mechanism called Web Services Addressing 1.0, basing its work on the WS-Addressing Member Submission. The group is chartered to produce the a number of deliverables, including the Web Services Addressing 1.0 specification...

Services Description (Web Services Description Working Group): "A Web service's interface is described in a way that allows service requesters to easily find out how to make use of the service: (1) What is the format of the messages? (2) What concrete protocols does the service use to exchange these messages? (3) What is the address of the endpoints providing this service? The Web Services Description Working Group was chartered in January 2002 to design a language for describing interfaces to and interaction with Web services. The group based its work on the Web Services Description Language (WSDL) 1.1 specification to produce the Web Services Description Language (WSDL) Version 2.0.

Choreography Description Language (Web Services Choreography Working Group): While WSDL 2.0 describes a single service, it is interesting to combine simple services to provide complex functionality. Currently, natural language descriptions have to accompany a WSDL description to outline the obligations of the participants and to explain how to use a service (sequencing, state management, etc.). The next step is to replace these somewhat imprecise instructions with precise language. The Web Services Choreography Working Group was chartered in January 2003 to design a language to compose and describe the relationships and message exchange between Web services. This composition is known as choreography of Web services. The Working Group published a Last Call Working Draft of the Web Services Choreography Description Language Version 1.0.

Semantic Web Services Interest Group: The mission of the Semantic Web Services Interest Group is to provide an open forum for W3C Members and non-Members to discuss Web services topics and is oriented towards integration of Semantic Web technology into the ongoing Web services work at W3C. Participation in the Semantic Web Services Interest Group is open to the public. Any person interested in the issues and applications of Web services is eligible to participate..." [adapted from the W3C Web Services Activity Statement]