Understanding .NET: A Tutorial and Analysis (Independent Technology Guides)

Microsoft views .NET as a vision, a platform for the digital future. A more concrete and equally accurate way to think about this new initiative is to understand that .NET is a brand, one that Microsoft has applied to several different technologies. Some of these technologies are entirely new, providing new services and new possibilities. Others allow an updated approach to creating the kinds of Windows applications we know today. Still other parts of the .NET family are just new releases of existing technologies dressed up with the .NET brand.

.NET is a brand applied to a range of technologies

Web services are a core technology in .NET

The most important new technology in .NET is Web services. As the name suggests, a Web service provides some function that can be invoked programmatically via the Web. Most technologies that carry the .NET brand have direct support for Web services in some way, yet .NET is more than just Web services. The technologies that Microsoft has placed under the .NET umbrella today include the following:

• The .NET Framework: Includes the Common Language Runtime (CLR) and the .NET Framework class library. The CLR is a standard foundation for building a range of new applications, while the .NET Framework class library provides standard implementations of many new services for CLR-based applications. Among the technologies in the library are ASP.NET, which is the next generation of Active Server Pages; ADO.NET, the next generation of ActiveX Data Objects; support for building and using Web services; and much more. Microsoft is also releasing a trimmed-down incarnation of the .NET Framework called the .NET Compact Framework. This version is intended for use in smaller devices, such as personal digital assistants (PDAs).

• Visual Studio.NET: Supports several programming languages that can be used with the .NET Framework. These languages include Visual Basic.NET, which is the next generation of Visual Basic; an enhanced version of C++; and a wholly new language called C#^[1] designed explicitly for the .NET Framework.

  ^[1] Pronounced C sharp, as in the musical note.

• .NET My Services: A group of services that allow users to store and access personal information, such as a calendar and address book, on Internet-accessible servers. These services also provide more general features such as authentication, which allows a client to prove its identity, and a way to send alert messages to clients on various devices.

• The .NET Enterprise Servers: A family of software servers that includes BizTalk Server 2000, Application Center 2000, Commerce Server 2000, Host Integration Server 2000, SQL Server 2000, Exchange Server 2000, Mobile Information Server 2001, and Internet Security and Acceleration Server 2000. In their current releases, these products are largely independent from the other .NET technologies listed here. They don't, for example, make use of the .NET Framework, nor do they provide much direct support for Web services.

Understanding .NET requires understanding Web services. It also requires grasping at least the basics of each of the .NET technologies just listed. This chapter provides an overview of all of these topics.