Introduction

This book is designed to provide insight into some of the advanced Web service specifications that have been proposed to enhance the functionality of SOAP- based messaging while maintaining the interoperability of Web service applications. In particular, this book focuses primarily on the specifications that are being supported in version 2.0 of Microsoft Web Services Enhancements (WSE). Therefore, I focus mainly on the key areas of Web service security and reliable messaging, with a brief foray into transacted Web services, which I find very interesting even though they arent supported by WSE.

This book isnt intended to provide a comprehensive discussion of all emerging XML messaging technologies and specifications, nor should it be considered a full treatment of .NET programming or the final word on the overall Microsoft vision for Web services. Although I try to provide some introductory material on SOAP and Web services in Chapter 1, to get the most out of this book, you should already have at least a rudimentary understanding of XML, SOAP messaging, Web services description and discovery, and .NET programming. Because all of my code samples are written in C#, Visual Basic .NET programmers might want to spend some time reviewing the basics of C#. But since both are .NET languages, it shouldnt be too hard for Visual Basic .NET programmers to follow my code samples.

Who Should Read This Book

Anyone who has interest in Web services standards and implementing Web services will benefit from reading this book. But specifically , these groups will get the most out of this book:

• .NET Web services developers who want to secure their Web services while maintaining interoperability

• .NET developers who are new to Web services and are trying to find out whether they are worth the hype

• IT professionals interested in where the field of Web services is headed

• IT managers who need to understand what Web services can do, how they can be secured, and how interoperability can be achieved

This book also assumes that you already have at least a rudimentary understanding of XML, SOAP, C#, and Visual Studio; some familiarity with .NET programming principles; and some familiarity with Web security problems. It isnt a general overview of Web servicesfor a general overview, see any one of many excellent books on Web services, in particular, Building XML Web Services for the Microsoft .NET Platform by Scott Short (Microsoft Press, 2002).