Windows Communication Foundation (WCF)
WCF allows you to architect services by offering a standards- based framework and a composable architecture. The three key design philosophies for WCF are interoperability, productivity and service-oriented development.Microsoft provides a number of messaging layer channels and service model layer behaviours that can be added and removed easily. It also allows you to define your own custom instances, for example you can write or buy a custom encoder for ASCII and insert it as a reusable channel in the messaging layer that can be used across various systems. WCF interoperates with existing investments and combines and extends existing Microsoft distributed systems technologies like Enterprise Services, System.Messaging, Microsoft .NET Remoting, ASMX and Web Services Extensions (WSE). This change implies that you can use a single model for different types of application behaviours which significantly reduces the complexity in application development. WCF also offers interoperability with non-Microsoft applications through support of the WS-I basic profile and a number of additional WS-* standards.
Finally in terms of productivity you can get a significant order of magnitude difference in developing secure transactional web services using WCF. Think of WCF as tens of thousands of lines of code that you would need to develop, generate and maintain, but instead are provided now as part of the base framework. WCF offers one of the first core programming frameworks that have been designed from the ground-up for services oriented development.
Windows Workflow (WF)
Workflow Foundation is an enterprise class workflow development framework and engine that has taken declarative workflow mainstream for the first time. WF supports human, system, sequential and state-machine workflows. It provides runtime infrastructure, flexible flow control, long running and stateful work flows and runtime and design time transparency and auditing capabilities for compliance and record management. Workflow Foundation allows you to define a workflow as a set of activities. Activities are the unit of execution and allow for easy re-use and composition. Basic activities are steps within a workflow while composite activities contain other activities. You can add and remove activities even when a workflow is already in progress allowing you significant flexibility in terms of change. Workflow Foundation provides a base activity library out-of-the-box and a framework for partners and customers to easily author custom activities.In terms of authoring options, you can use XAML mark-up only, mark-up plus code or code-only. Visual Studio 2005 Designer for Workflow Foundation is available as a downloadable plug-in and provides a drag-and-drop design surface, intuitive graphical tools, integration with the Properties window, debugging and graphic Commenting capabilities.
