Windows Communication Foundation Overview

The global acceptance of Web services, which includes standard protocols for application-to-application communication, has changed software development. For example, the functions that Web services now provide include security, distributed transaction coordination, and reliable communication. The benefits of the changes in Web services should be reflected in the tools and technologies that developers use. Windows Communication Foundation (WCF) is designed to offer a manageable approach to distributed computing, broad interoperability, and direct support for service orientation.

WCF simplifies development of connected applications through a new service-oriented programming model. WCF supports many styles of distributed application development by providing a layered architecture. At its base, the WCF channel architecture provides asynchronous, untyped message-passing primitives. Built on top of this base are protocol facilities for secure, reliable, transacted data exchange and broad choice of transport and encoding options.

The typed programming model (called the service model) is designed to ease the development of distributed applications and to provide developers with expertise in ASP.NET Web services, .NET Framework remoting, and Enterprise Services, and who are coming to WCF with a familiar development experience. The service model features a straightforward mapping of Web services concepts to those of the .NET Framework common language runtime (CLR), including flexible and extensible mapping of messages to service implementations in languages such as Visual C# or Visual Basic. It includes serialization facilities that enable loose coupling and versioning, and it provides integration and interoperability with existing .NET Framework distributed systems technologies such as Message Queuing (MSMQ), COM+, ASP.NET Web services, Web Services Enhancements (WSE), and a number of other functions.

Windows Workflow Foundation Overview

Windows Workflow Foundation is a framework that enables users to create system or human workflows in their applications written for Windows Vista, Windows XP, and the Windows Server 2003 operating systems. It consists of a namespace, an in-process workflow engine, and designers for Visual Studio 2005. Windows Workflow Foundation can be used to solve simple scenarios, such as showing UI controls based on user input, or complex scenarios encountered by large enterprises, such as order processing and inventory control. Windows Workflow Foundation comes with a programming model, a rehostable and customizable workflow engine, and tools for quickly building workflow-enabled applications on Windows.

Scenarios that Windows Workflow Foundation addresses include:

* Enabling workflow within line-of-business applications.

* User-interface page flows.

* Document-centric workflows.

* Human workflows.

* Composite workflows for service-oriented applications.

* Business rule-driven workflows.

* Workflows for systems management.

Windows Workflow Foundation provides a consistent and familiar development experience with other .NET Framework 3.0 technologies, such as Windows Communication Foundation and Windows Presentation Foundation. The Windows Workflow Foundation API provides full support for Visual Basic .NET and C#, a specialized workflow compiler, debugging within a workflow, a graphical workflow designer, and developing your workflow completely in code or in markup. Windows Workflow Foundation also provides an extensible model and designer to build custom activities that encapsulate workflow functionality for end users or for reuse across multiple projects.

The concepts in this section are inherent to Windows Workflow Foundation. They are briefly described here to provide a basic understanding. The Programming Guide section of this SDK provides implementation details and a deeper level of knowledge.