What is Microsoft .NET? Because this book is all about Microsoft .NET, it is important to first understand what.NET is. .NET is a technology platform for development and deployment of business applications using a set of technologies—.NET Framework, multiple programming languages, tools (particularly Visual Studio .NET), applications (including Microsoft Office System), and server technologies (known as Windows Server System, earlier called .NET Enterprise Servers). It is also important to understand that currently most (except SharePoint Portal Server 2003 and BizTalk Server 2004) of the enterprise servers are built on top of Windows DNA technologies, although they do typically have integration and interoperability mechanisms with the .NET Framework.

Microsoft .NET is a very significant change from Microsoft's previous technology Windows DNA platform (COM/DCOM/ASP/VB/MFC/ATL). Announced only three years ago in 2000, .NET received a strong response and created excitement in the IT community. A number of organizations started to develop (and even deploy!) applications on the new platform, even in its early beta stages. However, the platform is still evolving—evolution from the 1.0 release of the framework to an enhanced 1.1 release. Even though a lot of what .NET was about has to do with the notion of Web services–based service–oriented architecture, a key reason behind this success has been the enormous amount of prebuilt functionality (available as class libraries) that are available within the .NET Framework itself. Key highlights of the .NET platform include the following:

• A consistent programming model for Web applications, desktop applications, Web services, and mobile applications.

• Tight integration with XML and Web services technologies and standards.

• Choice of programming languages—the newly introduced C#, managed extensions to C++, Visual Basic .NET, JScript .NET, Visual J#, and a whole set of third-party programming languages have been .NET enabled.

• A common language runtime (CLR) so that applications and components developed in one language can be used in another language in a seamless mechanism.

• No more different programming models with Visual C++ and Visual Basic.

• No more of the "DLL Hell."

• Common Visual Studio .NET development tools, whether you are developing Windows applications, Web applications, wireless and speech applications, Web services, Web parts for portals, content management templates, or integrating business processes.

At the same time, what the enriched functionality implies is that application designers and developers need to be in constant sync with the various components of the platform, which leads to the goal that I had set out while writing the book—to cover essential aspects of key components of the .NET platform. The rule that has been used in the process of writing the book has been to focus on how these technologies can be rapidly applied to develop and deploy real-world applications; call it Rapid Learning for the Rapid Application Development (RAD) environment, the .NET platform.

If you or your organization has opted to utilize the .NET platform for development of new applications or are in the process of migration from your existing Visual Basic/COM/MFC applications into the .NET platform, you have made the right decision. A round of applause for you for picking up the book; hopefully, you will find a lot of queries and questions answered around .NET.