The Windows Communications Foundation (WCF), formerly code named indigo, is a programming framework that is used to build applications that inter-communicate. It is part of the .Net Framework, and is one of the four new APIs that was introduced with version 3.0 of the framework and that is included in Microsoft Vista, and Windows Server 2008.

Learning WCF was written by Michele Leroux Bustamante, that indigo girl herself who is the Chief Architect of IDesign Inc. and Microsoft Regional Director for San Diego. The book is written for the intermediate to advanced developer who is looking for a comprehensive introduction to WCF for building a Service Oriented Architecture (SOA). It is assumed that you are familiar with .NET 2.0 and Visual Studio 2005. It will help if you are also familiar with Windows Forms, ASP.NET, and Windows Service Applications. Learning WCF is 607 pages and is divided into eight chapters.

Chapter 1, "Hello Indigo," introduces you to WCF beginning with a look at the purpose of WCF, the problems it solves and its alignment with SOA. It will give you insight into what you will need to know to work with WCF, as well as touching on the architecture of WCF.

Chapter 2, "Contracts," focuses on contracts and serialization. You will see how to design service contracts, data contracts, as well as how to work with other serializable types to solve specific challenges. You will also see how services expose metadata to clients for proxy generation and how metadata exchange supports this. In essence you will learn everything you need to know about contracts.

Chapter 3 covers "Bindings," which are the heart of WCF. They are used to configure the communications protocols supported by services, including those related to interoperable messaging. Here you will see the uses for each of the core bindings, how bindings configure communications channels for clients and services, and you will find out when and why to apply custom bindings to handle special situations.

Chapter 4, "Hosting," examines the various hosting options for WCF services. These include Windows applications, Windows services, IIS, and the Windows Activation Service. You will find out about the hosting features and protocols supported by each environment, about the underlying hosting architecture they share and reasons for selecting each environment.

Chapter 5, "Instancing and Concurrency," explains how to configure services to run as singletons, to provide support for application sessions, or to run as scalable sessionless services. Concurrency modes that impact the number concurrent requests and other service throttling behaviors are also discussed.