The Microsoft .NET Platform consists of five main components, as shown in Figure 1-1. At the lowest layer lies the operating system (OS), which can be one of a variety of Windows platforms, including Windows XP, Windows 2000, Windows Me, and Windows CE. As part of the .NET strategy, Microsoft has promised to deliver more .NET device software to facilitate a new generation of smart devices.
On top of the operating system is a series of .NET Enterprise Server products that simplify and shorten the time required to develop and manage large-scale business systems. These server products include Application Center 2000, BizTalk Server 2000, Commerce Server 2000, Exchange Server 2000, Host Integration Server 2000, Internet Security and Acceleration Server 2000, and SQL Server 2000.
Since Web Services are highly reusable across the Web, Microsoft plans to provide a number of building-block services that applications developers can use, for a fee. An example of building-block service is Microsoft Passport, which allows you to use a single username and password at all web sites that support Passport authentication. On March 19, 2001, Microsoft announced another set of Web Services with the codename HailStorm. This product encompasses a set of building-block services that support personalization, centered entirely on consistent user experiences. Microsoft plans to add newer services, such as calendar, directory, and search services. Third-party vendors are also creating new Web Services of their own.
At the top layer of the .NET architecture is a brand new development tool called Visual Studio.NET (VS.NET), which makes possible the rapid development of Web Services and other applications. A successor of Microsoft Visual Studio 6.0, VS.NET is an Integrated Development Environment (IDE) that supports four different languages and features such as cross-language debugging and the XML Schema Editor.
And at the center of .NET is the Microsoft .NET Framework—the main focus of this book. The .NET Framework is a new development and runtime infrastructure that will change the development of business applications on the Windows platform. It includes the Common Language Runtime (CLR) and a common framework of classes that can be used by all .NET languages.