Web Services

What Are Web Services?
In recent years, the imperative to connect people, information, and processes has changed the way software is being developed. Successful IT systems increasingly require interoperability across platforms and flexible services that can easily evolve over time. This has led to the prevalence of XML as the universal language for representing and transmitting structured data that is independent of programming language, software platform, and hardware.

Building on the broad acceptance of XML, Web services are applications that use standard transports, encodings, and protocols to exchange information. With broad support across vendors and businesses, Web services enable computer systems on any platform to communicate over corporate intranets, extranets, and across the Internet with support for end-to-end security, reliable messaging, distributed transactions, and more.

Web services are based on a core set of standards that describe the syntax and semantics of software communication: XML provides the common syntax for representing data; the Simple Object Access Protocol (SOAP) provides the semantics for data exchange; and the Web Services Description Language (WSDL) provides a mechanism to describe the capabilities of a Web service. Additional specifications, collectively referred to as the WS-* architecture, define functionality for Web services discovery, eventing, attachments, security, reliable messaging, transactions, and management.

Microsoft Support for Web Services
Since their inception, Web services have formed the foundation of Microsoft's interoperability efforts. In addition to building its entire developer platform around Web services with .NET, Microsoft continues its commitment to the standardization process—driving vendor consensus and interoperability for both horizontal and vertical standards.

In the coming years, Web services will play an even more pivotal role across the Microsoft platform—with new developer offerings, an amplified focus on IT operations and management, expanded offerings for consumers and information workers, innovation in the business applications market and increased community outreach. For developers, the Windows Communication Foundation (WCF) is Microsoft's next generation platform for building secure, reliable, and transacted Web services. For IT Professionals, Windows Server and Microsoft Operations Manager will enable the management of heterogeneous software and hardware systems using WS-Management. For consumers, Windows Vista will support the discovery of and interaction with Web services-enabled devices, such as printers, digital cameras, and home control systems.

In addition, Microsoft's vision for Web services extends beyond support in its own products. As a platform vendor, Microsoft is focused on delivering a Web services platform upon which other vendors and customers can build customized solutions.

Standards and Interoperability
Broad vendor agreement on standards and proven interoperability have set Web services apart from integration technologies of the past. During the ongoing process of interoperability and standardization, Microsoft has driven efforts to create both horizontal as well as industry-specific Web services standards.

Horizontal Web Services Standards
WS-* Architecture
As the Web services market rapidly expanded, the need for advanced standards governing Web services security, reliability, and transactions arose. Microsoft and other vendors across the industry responded to this need by authoring a set of specifications referred to collectively as the WS-* architecture. The goal of these specifications is to provide a blueprint for advanced functionality while retaining the simplicity of basic Web services.

The most important attribute of the WS-* architecture is composability. Protocol composability enables incremental development of Web services solutions only as individual requirements (such as security, reliable messaging, attachments, discovery, etc.) are needed. In isolation, each of these requirements solves an elemental need. In composition, they address higher-level functionality commonly required by distributed applications. As such, the WS-* specifications can be used either independently or in combination with one another. This eliminates the complexity and overhead associated with specifications that attempt to define multiple capabilities or are tightly coupled with other specifications. It also enables developers to apply only the specific functionality needed to solve the immediate need. As new application requirements arise, new specifications can be authored without compromising backwards compatibility.



Vertical Web Services Standards
The agreement on horizontal Web service standards, such as XML, SOAP, and the WS-* architecture created the foundation for the emergence of vertical Web services standards. Microsoft has played an active role in the creation of these standards, driving over a dozen vertical standards in the education, health care, finance, automotive, and telecommunication industries through working relationships with the following standards bodies:

· Association for Cooperative Operations Research and Development (ACORD)

· Association for Retail Industry Standards (ARTS)

· Automotive Industry Action Group (AIAG)

· Clinical Data Interchange Standards Consortium (CDISC)

· Continental Automated Buildings Association (CABA)

· Distributed Management Task Force (DMTF)

· EAN International and the Unified Code Council (EAN.UCC)

· EPCglobal

· European Forum for Electronic Business (EEMA)

· Financial Information eXchange (FIX/FPL)

· Health Level Seven (HL7)

· Human Resources XML (HR-XML)

· IMS Global Learning Consortium (IMS)

· Interactive Financial eXchange Forum (IFX)

· OPC Foundation (OPC)

· Open Financial Exchange Consortium (OFX Consortium)

· Open Travel Alliance (OTA)

· RosettaNet

· Schools Interoperability Framework (SIF)

· Society for Worldwide Interbank Financial Telecommunications (SWIFT)

· TeleManagement Forum (TM Forum)


Reference: http://msdn.microsoft.com/webservices/default.aspx?pull=/library/en-us/dnwebsrv/html/wsmsplatform.asp#wsmsplat_topic2