(Indigo was the code name for WCF)
WCF is an SDK for developing and deploying services on Windows. WCF provides a runtime environment for your services, enabling you to expose CLR types as services, and to consume other services as CLR types. . WCF is Microsoft’s implementation of a set of industry standards defining service interactions, type conversion, marshaling, and various protocols’ management. Because of that, WCF provides interoperability between services. WCF provides developers with the essential off-the-shelf plumbing required by almost any application, and as such, it greatly increases productivity.
WCF provides many useful facilities for developing services, such as hosting, service instance management, asynchronous calls, reliability, transaction management, disconnected queued calls, and security.
WCF functionality is included in a single assembly called System.ServiceModel.dll in the System.ServiceModel namespace.
WCF is part of .NET 3.0 and requires .NET 2.0, so it can only run on operation systems that support it. Presently this list consists of Windows Vista (client and server), Windows XP SP2, and Windows Server 2003 SP1 or their later versions.
