World Wide Web Consortium Issues SOAP Version 1.2 as a W3C Recommendation

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W3C XML Protocol Working Group Delivers Essential Component for Web Services

Testimonials | Frequently Asked Questions -- 24 June 2003 -- The World Wide Web Consortium (W3C) today releases the SOAP Version 1.2 Recommendation, consisting of the SOAP Version 1.2 Primer, the SOAP Version 1.2 Messaging Framework, SOAP Version 1.2 Adjuncts, and the SOAP Version 1.2 Specification Assertions and Test Collection. SOAP Version 1.2 is a lightweight protocol intended for exchanging structured information in a decentralized, distributed environment such as the Web. A W3C Recommendation is the equivalent of a Web standard, indicating that this W3C-developed specification is stable, contributes to Web interoperability, and has been reviewed by the W3C Membership, who favor its adoption by the industry.

"Web services make good on the promise of interoperable applications only when the technical foundations are shared, robust, and achieve expected performance," explained Tim Berners-Lee, W3C Director. "Today, W3C Members have endorsed SOAP Version 1.2, the first version of SOAP to have undergone rigorous testing and implementation, and to support a full complement of Web standards. Web services customers and developers alike demand an XML-based Web services protocol that powers the full range of applications and Web technologies they can imagine using. Now that SOAP Version 1.2 is here, they have it."

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 Version 1.2 specification, using the W3C Note SOAP 1.1 as a starting point. Now that the Working Group produced multiple drafts, received significant feedback from developers, identified interoperable implementations, and received comprehensive review from the W3C Membership, SOAP Version 1.2 is ready for widespread deployment.

SOAP Version 1.2 Provides Stable Support for W3C Recommendations, Refined Processing Model

The XML Protocol Working Group 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.

An introduction for users such as application designers, the Primer is an easily understandable tutorial that describes the features of SOAP Version 1.2 through examples and links to the specification. The SOAP Version 1.2 specification provides a framework for XML-based messaging systems in two parts, the Messaging Framework and Adjuncts:

SOAP Version 1.2 Messaging 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 Version 1.2 Adjuncts completes the specification. 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 (Hypertext Transfer Protocol), allowing SOAP messages to be exchanged using the mechanisms of the World Wide Web.

Intended to help implementers write SOAP processors, the Specification Assertions and Test Collection provide a set of tests drawn from the assertions found in the Messaging Framework and Adjuncts. These tests show whether the assertions are implemented in a SOAP processor, and are designed to foster interoperability between different SOAP Version 1.2 implementations.

In addition to fulfilling requirements spelled out in the Working Group charter, SOAP Version 1.2 integrates core XML technologies. SOAP Version 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 the Web Services Description Language (WSDL). It also makes use of Namespaces in XML as a flexible and lightweight mechanism for handling XML language mixing.

SOAP Version 1.2 describes a refined processing model, thus removing ambiguities found in SOAP 1.1. SOAP Version 1.2 includes improved error messages that will help developers to write better applications.

SOAP Version 1.2 Implementations Successful, Already in Product

After its Candidate Recommendation period, the W3C XML Protocol Working Group tracked seven SOAP Version 1.2 implementations from W3C Member organizations and independent developers to ensure the viability and interoperability of implementations based on the specification. The Working Group previously identified and resolved over 400 technical and editorial issues raised in public review of SOAP 1.1 and the resulting SOAP Version 1.2.

Current participants in the Working Group include industry and technology leaders: AT&T; BEA Systems; Canon; DaimlerChrysler Research and Technology; Ericsson; Fujitsu Limited; IBM; IONA Technologies; Macromedia; Matsushita Electric Industrial Co., Ltd.; Microsoft Corporation; Oracle Corporation; SAP AG; SeeBeyond; Software AG; Sun Microsystems; and Systinet.

Developer communities outside of the W3C Membership and other organizations with related interests have provided valuable input to the creation of SOAP Version 1.2. Many W3C Members have issued testimonials, with commitments to current or future implementations of SOAP Version 1.2.

About the World Wide Web Consortium [W3C]

The W3C was created to lead the Web to its full potential by developing common protocols that promote its evolution and ensure its interoperability. It is an international industry consortium jointly run by the MIT Laboratory for Computer Science (MIT LCS) in the USA, the European Research Consortium for Informatics and Mathematics (ERCIM) headquartered in France, and Keio University in Japan. Services provided by the Consortium include: a repository of information about the World Wide Web for developers and users, and various prototype and sample applications to demonstrate use of new technology. To date, over 400 organizations are Members of the Consortium. For more information see


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Testimonials for W3C's SOAP 1.2 Recommendation

BEA Systems | IBM | Microsoft Corporation | Oracle Corporation | SAP AG | SeeBeyond | SunMicrosystems | Systinet Corporation | webMethods Inc. | WS-I

BEA Systems

BEA is very pleased to see SOAP 1.2 become a W3C Recommendation. SOAP 1.2 provides a key specification for building Web services. The technical improvements, as well as the Royalty-Free status, will foster faster adoption of Web services in the IT industry. BEA continues to support the standardization of Web services specifications in a Royalty-Free manner, and the W3C as an essential forum of such foundational work. BEA Systems, a leader in standards, supports SOAP 1.2 in our WebLogic Platform.

-- Ed Cobb, Vice President of Standards and Architecture, BEA Systems


SOAP is the foundation technology for Web services and a critical component of the emerging technical infrastructures of Grid and IBM's e-Business On Demand computing initiative. IBM continues to be instrumental in driving SOAP to become a platform and language-neutral mechanism for application integration suitable for widespread deployment, and in developing the SOAP 1.2 specification at W3C. IBM is committed to the development of open standards for Web services and their incorporation into our products, thus ensuring the interoperability and viability of solutions for our customers, and we are pleased to endorse SOAP 1.2 as a W3C Recommendation.

-- Karla Norsworthy, Director of Dynamic e-business Technologies, IBM

Microsoft Corporation

Microsoft Corp., IBM Corp., DevelopMentor Inc., Lotus Development Corp. and UserLand Software Inc. submitted SOAP version 1.1 to W3C in 2000 to kick-start the standards and design work for Web services. The W3C SOAP version 1.2 recommendation is a milestone in the evolution of the Web services architecture. SOAP version 1.2 builds on the initial specification's early success and widespread adoption, while bringing significant technical benefits to applications developers. Having provided product support and co-authors for all SOAP versions, Microsoft will continue that support with SOAP version 1.2, infusing the specification across products and services, including the next versions of .NET Framework and Microsoft Visual Studio development system, with the goal of interoperability across heterogeneous environments.

-- Steven VanRoekel, Director of Web Services, Microsoft Corporation

Oracle Corporation

As a major contributor to the XML Protocol Working Group, Oracle is pleased to endorse the W3C SOAP 1.2 Recommendation. This standard represents a significant step toward industry-wide interoperability of Web services and further demonstrates the importance of the W3C's open, consensus-driven process and rigorous public review. Oracle will be fully supporting SOAP 1.2 across all of its products, including Oracle9i Application Server, Oracle9i Database, Oracle9i JDeveloper, and Oracle E-Business Suite, and encourages customers and other vendors to quickly adopt this important standard.

-- Don Deutsch, Vice President of Standards Strategy and Architecture, Oracle Corporation


SAP AG is delighted to see SOAP 1.2 moving into its final stage as a W3C Recommendation. Based upon the feedback from implementers and other end-user groups, the W3C has greatly enhanced the messaging, creating a more mature specification. SAP expects quick, broad industry adoption of the popular W3C Web services protocol and will consider SOAP 1.2 support in SAP's NetWeaver product based upon our customer needs for a fully interoperable platform.

-- Franz-Josef Fritz, Vice President, Technology Architecture, SAP AG


Enabling a services-oriented architecture (SOA) based on Web Services requires a strong commitment to global standards, such as SOAP Version 1.2. Our participation in the W3C's XML Protocol Working Group and support for SOAP in the SeeBeyond® Integrated Composite Application Network (SeeBeyond ICAN) Suite are demonstrations of our commitment to the evolution of Web Services.

-- Alan Davies, Vice President of Standards, SeeBeyond

Sun Microsystems

As a long-time supporter of standards-based solutions and their value to customers in containing costs and enabling vendor choice, Sun applauds the W3C in moving SOAP 1.2 to final standardization. SOAP 1.2's improvements for distributed XML-based messaging is an important point of progress for the industry, and customers can expect to see Java platform and Sun ONE product support for this latest version of SOAP in the near future.

-- Connie Weiss, Director of Web Technologies and Standards, Sun Microsystems, Inc.

Systinet Corporation

The SOAP 1.2 specification is a major step forward in providing robust standards that will further the adoption of Web services. Systinet provided a reference implementation for SOAP 1.2, and we are pleased to be involved in this important effort.

-- Roman Stanek, CEO, Systinet Corporation

webMethods, Inc.

webMethods has long been a leader of industry standards. Consequently, we are extremely pleased to have not only contributed to the development of the SOAP 1.2 standard, but also to also see it approved as a Recommendation. With more than 400 issues resolved, we believe SOAP 1.2 will help increase the adoption rate of Web Services. Before businesses can be comfortable deploying Web services throughout their organizations, they need to know that these deployments will be viable and interoperable. SOAP 1.2 goes a long way towards meeting these needs. webMethods is looking forward to supporting SOAP 1.2 within the webMethods Integration Platform, as this standard is a key component to our customers’ Web Services-based integration strategy.

-- Andy Astor, Vice President of Enterprise Web Services, webMethods, Inc.


WS-I is pleased to see the release of the SOAP 1.2 Recommendation from the W3C. This is a valuable step forward for the popular SOAP specification, and we expect there will be broad industry adoption. WS-I remains committed to supporting industry-wide collaboration in the creation of open and interoperable standards. As SOAP 1.2 is put into service, WS-I will consider incorporating the specification into a future version of the Basic Profile and will respond as neccessary if interoperability issues are identified.

-- Tom Glover, Chairman, WS-I

SOAP Version 1.2 - Frequently Asked Questions

This document lists some frequently asked questions about the SOAP Version 1.2 specifications and provides answers to those questions. For more information about SOAP Version 1.2, see the Working Group Home Page.


  1. What is SOAP Version 1.2?
  2. Who has implemented SOAP Version 1.2?
  3. Where can I find an introduction to SOAP Version 1.2?
  4. What is new in SOAP Version 1.2?
  5. Why switch to SOAP Version 1.2?
  6. How can I be sure my implementation is interoperable?
  7. Is SOAP Version 1.2 secure?
  8. Can I use SOAP Version 1.2 without WSDL?
  9. So, when do I need WSDL?
  10. What are my options if I want to use WSDL?
  11. Is SOAP Version 1.2 internationalized?
  12. Can I use other underlying transport protocols in SOAP Version 1.2?
  13. Will my SOAP Version 1.2 implementation work with SOAP/1.1 clients?

What is SOAP Version 1.2?

SOAP Version 1.2 is a messaging framework with a set of extensions. The specification is in three distinct documents:


Who has implemented SOAP Version 1.2?

The SOAP Version 1.2 Implementation Report has a list of implementors known to the XML Protocol Working Group, as well as a status of their implementation. The list is not exhaustive.

Where can I find an introduction to SOAP Version 1.2?

The SOAP Version 1.2 Primer gives a good introduction to SOAP 1.2, and is recommended reading.

What is new in SOAP Version 1.2?

SOAP Version 1.2 is based on a layered and extensible model.

  1. Over 400 issues raised both in the SOAP 1.1 and early SOAP 1.2 specifications have been resolved.
  2. SOAP version 1.2 supports Web standards such as XML Schema and XML Infoset.
  3. The "transport" layer makes it easy to switch between protocols like HTTP, BEEP and others to fit your application needs.
  4. Extensions and the processing of those extensions has been improved and clarified, to ensure more extensibility and interoperability.
  5. Error reporting has been improved.

For more technical details, the SOAP Version 1.2 Part 0 (Primer) has a complete list of changes from SOAP/1.1 to SOAP Version 1.2

Why switch to SOAP Version 1.2?

SOAP Version 1.2 provides more - and proven - interoperability, support for Web standards, and an easier way to extend and update your applications. It also allows you to define applications that can scale better through a more effective use of Web infrastructure - namely with the option of using the HTTP binding. For a more complete reply, see From SOAP/1.1 to SOAP Version 1.2 in 9 points.

How can I be sure my implementation is interoperable?

You should see the SOAP Version 1.2 Specification Assertions and Test Collection, and contact the implementers listed in the implementation report to set up tests.

Is SOAP Version 1.2 secure?

An application is as secure as its design is. SOAP Version 1.2 may use some security features, but in the end, like in all current distributed applications, it is up to the application itself to take care of security (buffer overflow, denial of services...)

Can I use SOAP Version 1.2 without WSDL?

Yes, SOAP 1.2 is not dependent on WSDL (Web Services Description Language). There are many interesting situations in which SOAP can be used without WSDL. Indeed, early adopters of SOAP used it for many months before languages similar to WSDL became available.

So, when do I need WSDL?

WSDL is used primarily as a means of documenting, in machine readable form, the details of particular SOAP-based protocols. Many WSDL-enabled tools can use these descriptions to help you build SOAP applications. Without WSDL, you may have to tailor more of your code by hand.

What are my options if I want to use WSDL?

Several options are available:

  • WSDL toolkit vendors have interim solutions. Check with them.
  • The SOAPBuilders development community has developed interim support for SOAP Version 1.2 using WSDL 1.1 and some degree of interoperability will be achievable using that [link]
  • The Web Services Description Working Group in W3C will support SOAP Version 1.2 in the next version of WSDL (WSDL 1.2). Check with them.

Is SOAP Version 1.2 internationalized?

SOAP Version 1.2 has provisions for internationalization, including the ability to provide multiple error messages in different languages, encodings, character sets. Applications themselves still have to be internationalized, but that is a separate matter. SOAP Version 1.2 itself puts no restriction to a particular language.

Can I use other underlying transport protocols in SOAP Version 1.2?

One of the goals of SOAP Version 1.2 was to develop a clean way to change the underlying transport. Part 2 Adjuncts defines a rather complete mapping to HTTP, but you can define your own mapping to whatever protocol, using the SOAP Protocol Binding Framework defined in Part 1, Section 4.

Will my SOAP Version 1.2 implementation work with SOAP/1.1 clients?

Yes, but not directly. The client application will be notified that the current version being used is SOAP Version 1.2. The client application may switch to SOAP Version 1.2 for subsequent requests. See Part 1, Section 5.4.7

Yves Lafon, Carine Bournez

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