This book describes how to use COM+ component services in your application. It focuses on how to apply the technology, how to avoid specific pitfalls, and design guidelines. If you want to know more about COM+ in general and the nature of component technology, I recommend the following two books that helped me a great deal in my attempt to grasp COM+.

COM+ and the Battle for the Middle Tier by Roger Sessions (John Wiley & Sons, 2000) is hands down the best “why” COM+ book. It explains in detail, with excellent examples and in plain language, the need for software components and component services. For example, instead of the page or two this book includes on the motivation for using transactions, Sessions devotes two fascinating chapters to the topic. The book goes on to compare existing component technologies (such as COM, CORBA, and Java) and their corresponding suites of component services. It also contains a few case studies from real-life systems that use COM+. Roger Sessions also has a unique way of eloquently naming things—providing the most appropriate term, which is often not the name Microsoft uses. Whenever it makes sense, this book uses Sessions’ terminology, such as “instance management” instead of the Microsoft term “activation.”

Understanding COM+ by David S. Platt (Microsoft Press, 1999) is probably the best “what” COM+ book. The book describes the services available by COM+ and provides sidebar summaries for the busy reader. It is one of the first COM+ books, and Platt worked on it closely with the COM+ team.

I also used the MSDN Library extensively, especially the “Component Services” section, while writing this book. Although the information in this library tends to be terse, the overall structure is good. Use this book to learn how to apply COM+ productively and effectively, and use the MSDN Library as a reference for technical details and a source for additional information.