W3C has advanced SOAP Version 1.2 to Proposed Recommendation status, and the W3C XML Protocol Working Group has issued a request for final review of the four-part specification. SOAP Version 1.2 is "a lightweight protocol for exchanging structured information in a decentralized, distributed environment; it provides a standardized XML-based solution for data transport. The four parts include SOAP Version 1.2 Part 0: Primer, SOAP Version 1.2 Part 1: Messaging Framework SOAP Version 1.2 Part 2: Adjuncts, and SOAP Version 1.2 Specification Assertions and Test Collection. SOAP 1.2 "describes a refined processing model, thus removing ambiguities found in SOAP/1.1, and it includes improved error messages, thus helping developers to write better applications. In addition to fulfilling requirements spelled out in the WG charter, SOAP 1.2 integrates core XML technologies. SOAP 1.2 is designed to work seamlessly with W3C XML schemas, maximizing SOAP's utility with a broad range of XML tools, and paving the way for future work on WSDL. It also makes use of XML Namespaces as a flexible and lightweight mechanism for handling XML language mixing. After the Candidate Recommendation period, the W3C XML Protocol WG tracked seven SOAP 1.2 implementations from W3C Member organizations and independent developers to ensure the viability and interoperability of implementations based on the specification. The WG had already identified and resolved over 400 technical and editorial issues raised in public review of both the previous SOAP/1.1 specification and the resultant SOAP 1.2 specification." The final review period for SOAP Version 1.2 closes on June 07, 2003.

SOAP Version 1.2 Proposed Recommendation Documents

• SOAP Version 1.2 Part 0: Primer. Edited by Nilo Mitra (Ericsson). W3C Proposed Recommendation 07-May-2003. Version URL: http://www.w3.org/TR/2003/PR-soap12-part0-20030507/. Latest version URL: http://www.w3.org/TR/soap12-part0/. Previous version URL: http://www.w3.org/TR/2002/CR-soap12-part0-20021219/. "SOAP Version 1.2 Part 0: Primer is a non-normative document intended to provide an easily understandable tutorial on the features of the SOAP Version 1.2 specifications. In particular, it describes the features through various usage scenarios, and is intended to complement the normative text contained in Part 1 and Part 2 of the SOAP 1.2 specifications."

• SOAP Version 1.2 Part 1: Messaging Framework. Edited by Martin Gudgin (Microsoft) Marc Hadley (Sun Microsystems), Noah Mendelsohn (IBM), Jean-Jacques Moreau (Canon), and Henrik Frystyk Nielsen (Microsoft). W3C Proposed Recommendation 07-May-2003. Version URL: http://www.w3.org/TR/2003/PR-soap12-part1-20030507/. Latest version URL: http://www.w3.org/TR/soap12-part1/. Previous version URL: http://www.w3.org/TR/2002/CR-soap12-part1-20021219/. "SOAP Version 1.2 is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment. Part 1: Messaging Framework defines, using XML technologies, an extensible messaging framework containing a message construct that can be exchanged over a variety of underlying protocols..."

• SOAP Version 1.2 Part 2: Adjuncts. Edited by Martin Gudgin (Microsoft), Marc Hadley (Sun Microsystems), Noah Mendelsohn (IBM), Jean-Jacques Moreau (Canon), and Henrik Frystyk Nielsen (Microsoft). W3C Proposed Recommendation 07-May-2003. Version URL: http://www.w3.org/TR/2003/PR-soap12-part2-20030507/. Latest version URL: http://www.w3.org/TR/soap12-part2/. Previous version URL: http://www.w3.org/TR/2002/CR-soap12-part2-20021219/. "Part 2 defines a set of adjuncts that may be used with the SOAP messaging framework: (1) The SOAP Data Model represents application-defined data structures and values as a directed, edge-labeled graph of nodes. (2) The SOAP Encoding defines a set of rules for encoding instances of data that conform to the SOAP Data Model for inclusion in SOAP messages. (3) The SOAP RPC Representation defines a convention for how to use the SOAP Data Model for representing RPC calls and responses. (4) The section for describing features and bindings defines a convention for describing features and binding in terms of properties and property values. (5) The section on SOAP-Supplied Message Exchange Patterns and Features defines a request response message exchange pattern and a message exchange pattern supporting non-SOAP requests for SOAP responses. (6) The SOAP Web Method feature defines a feature for control of methods used on the World Wide Web. (7) The SOAP HTTP Binding defines a binding of SOAP to HTTP (RFC 2616) following the rules of the SOAP Protocol Binding Framework (SOAP Part 1)."

• SOAP Version 1.2 Specification Assertions and Test Collection. Edited by Hugo Haas (W3C), Oisin Hurley (IONA Technologies), Anish Karmarkar (Oracle Corp.), Jeff Mischkinsky (Oracle Corp.), Mark Jones (AT&T), Lynne Thompson (Unisys), and Richard Martin (Active Data Exchange). W3C Proposed Recommendation 07-May-2003. Version URL: http://www.w3.org/TR/2003/PR-soap12-testcollection-20030507/. Latest version URL: http://www.w3.org/TR/soap12-testcollection. Previous version URL: http://www.w3.org/TR/2002/WD-soap12-testcollection-20020626. "This document draws on assertions found in the SOAP Version 1.2 specifications, and provides a set of tests in order to show whether the assertions are implemented in a SOAP processor. The primary goal of this document is to foster interoperability between different SOAP 1.2 implementations. The document is intended to help implementors to write SOAP processors that comply with SOAP 1.2 specification, and interoperate with other SOAP processors that comply with SOAP 1.2 specification."

From the W3C Announcement May 7, 2003

The World Wide Web Consortium (W3C) today releases the SOAP Version 1.2 Proposed Recommendation, consisting of the SOAP 1.2 Messaging Framework; SOAP 1.2 Adjuncts, and a Primer. SOAP 1.2 is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment such as the Web. A W3C Proposed Recommendation is issued after review by the W3C Director, W3C Working Groups and the developer public, with evidence of implementation and interoperability. SOAP 1.2 has been sent to the W3C Membership for final review, which closes on 7 June 2003.

"Starting today, developers who may have hesitated to pick up SOAP 1.2 should take a look," stated Tim Berners-Lee, W3C Director. "After resolving over 400 issues - including over 150 from SOAP/1.1 and delivering evidence of rigorous implementations, the W3C XML Protocol Working Group has produced for final review a real SOAP standard - SOAP 1.2."

Robust Web Services Rely on Standardized, Flexible Models for Message Exchange Data transport is central to modern computing in the networked, decentralized, and distributed environment that is the Web. As XML has emerged as the preferred format for data, the challenge is for both the sender and the receiver to agree on an application level transfer protocol - whether the transfer is to occur between software programs, machines, or organizations.

Since its inception in September 2000, W3C's XML Protocol Working Group has worked on both XML Protocol Requirements and the SOAP 1.2 specification, using the W3C Note SOAP/1.1 as a starting point. After producing multiple drafts, receiving significant feedback from developers, and identifying interoperable implementations, the W3C XML Protocol Working Group (WG) believes its work on SOAP 1.2 is complete.

The XML Protocol WG has the goal of developing technologies which enable two or more peers to communicate in a distributed environment, using XML as the encapsulation language. Their solution allows a layered architecture on top of a simple and extensible messaging format, which provides robustness, simplicity, reusability and interoperability.

SOAP 1.2 provides a framework for XML-based messaging systems, in two parts - the Message Framework and Adjuncts. SOAP 1.2 Message Framework provides a processing model (the rules for processing a SOAP message), an extensibility framework (enabling developers to use extensions inside and outside the SOAP envelope), the message construct (the rules for constructing SOAP messages), and the protocol binding framework (the rules for specifying the exchange of SOAP messages over underlying protocols such as HTTP).

SOAP 1.2 Adjuncts defines a set of adjuncts. It includes rules for representing remote procedure calls (RPCs), for encoding SOAP messages, for describing SOAP features and SOAP bindings. It also provides a standard binding of SOAP to HTTP 1.1, allowing SOAP messages to be exchanged using the mechanisms of the World Wide Web.