The Internet's leading standards group updates its core draft specification for Web services, including clarifications that try to make its language more palatable.
The World Wide Web Consortium (W3C) this week published Web Services Description Language (WSDL) 1.2, a language based on XML (Extensible Markup Language) that defines the protocol for interactive services on the Web, as well as their data and location.
The W3C also published WSDL 1.2 Bindings, which shows how the specification can be used with Simple Object Access Protocol (SOAP) 1.2, HTTP (Hyptertext Transfer Protocol), and Multipurpose Internet Mail Extensions (MIME).
WSDL and the bindings are the latest in a series of Web services-related drafts out from the W3C. In recent months, the consortium released three drafts directly related to Web services: Web Service Description Usage Scenarios, which outline real-world uses of Web services; and the Web Services Architecture Requirements and Web Service Description Requirements, both of which are designed to clarify the W3C's goals in standardizing Web services.
The W3C last month published an XML Conformance Test Suite, aimed to help developers clean up the Web's XML in advance of a Web services release that will rely on valid XML markup. In February, the W3C called its update on XML Signature a significant tool for securing and authenticating documents exchanged over Web services.
This year's flurry of Web services releases follows a period of relative inaction at the W3C on the Web services front, and subsequent complaints from critics that the W3C was leaving Web services to fracture at the hands of competing providers. The W3C formed its Web Services Activity in January.
The W3C said WSDL 1.2 came with improvements over WSDL 1.1, including clarifications that made its language easier to use and understand, support for the W3C's XML Schemas and XML Information Set recommendations, and a way of conceptually defining description components that is simpler and more flexible than the current method. With Version 1.2, the W3C took out what it called "unnecessary and non-interoperable" technologies and improved the HTTP 1.1 binding.
The W3C also promised a binding for SOAP 1.2 and continued cooperation with the W3C's efforts in what it calls the Semantic Web. Critics have called the Semantic Web--an ambitious undertaking descended from the artificial intelligence world which aims to build a Web of documents that computers can "understand" as well as read--a distraction from the more practical and immediate demands of Web services.
A step ahead in status
Analysts said the new WSDL version made only minor technical progress, but marked a significant step in WSDL's status as a standard.
"It looks like a relatively modest step forward, a set of incremental improvements," said David Schatsky, analyst with Jupiter Research. "Probably the most significant aspect of it is that it represents the work of the W3C. With this draft of the spec, WSDL formally leaves the control of a small core group of vendors and becomes subject to the W3C process and technical requirements. It's an necessary--and expected--step toward cementing WSDL's status as a key, vendor-neutral standard."
In other W3C news, the consortium published drafts in the following areas:
• XPointer: The XML Linking Working Group published four working drafts and solicited comments through the end of July. XPointer is a way of addressing XML documents.
• Ontology Web Language: The Web Ontology Working Group updated its working draft of requirements for the Ontology Web Language 1.0. Web ontologies are sets of common terms that are useful to search services, software agents, and other applications relevant to the W3C's Semantic Web activity.
• Media Queries: Media Queries reached the penultimate stage of the W3C's recommendation process, advancing to Candidate Recommendation status. Media Queries is a module of the Cascading Style Sheets 3 specification and establishes a registry of media types a style sheet can be applied to.
• Amaya browser: The W3C released Version 6.2 of its Web browser and authoring tool, Amaya. The new version installs more easily on Microsoft's Windows operating system and has more features for international users. Amaya is available for download for the Solaris, Linux and Windows operating systems. The W3C has also published its source code.