MICROSOFT.NET

Microsoft.NET is product suite that enables organizations to build smart, enterprise-class web services. Note the important difference: .NET is a product strategy, whereas J2EE is a standard to which products are written.

Microsoft.NET is largely a rewrite of Windows DNA, which was Microsoft's previous platform for developing enterprise applications. Windows DNA includes many proven technologies that are in production today, including Microsoft Transaction Server (MTS) and COM+, Microsoft Message Queue (MSMQ), and the Microsoft SQL Server database.

The new .NET Framework replaces these technologies, and includes a web services layer as well as improved language support. The .NET application is hosted within a container, which provides qualities of service necessary for enterprise applications, such as transactions, security, and messaging services.

The business layer of the .NET application is built using .NET managed components. This layer performs business processing and data logic. It connects to databases using Active Data Objects (ADO.NET) and existing systems using services provided by Microsoft Host Integration Server 2000, such as the COM Transaction Integrator (COM TI). It can also connect to business partners using web services technologies (SOAP, UDDI, WSDL).

Business partners can connect with the .NET application through web services technologies (SOAP, UDDI, WSDL, BizTalk). Traditional 'thick' clients, web browsers, wireless devices connect to Active Server Pages (ASP.NET) which render user interfaces in HTML, XHTML, or WML. Heavyweight user interfaces are built using Windows Forms.

The .NET Framework

Microsoft.NET offers language-independence and language-interoperability. This is one of the most intriguing and fundamental aspects of the .NET platform. A single .NET component can be written, for example, partially in VB.NET, the .NET version of Visual Basic, and C#, Microsoft's new object-oriented programming language.

How does this work?

First, source code is translated into Microsoft Intermediate Language, sometimes abbreviated MSIL, sometimes IL. This IL code is language-neutral, and is analogous to Java bytecode.

The IL code then needs to be interpreted and translated into a native executable. The .NET Framework includes the Common Language Runtime (CLR), analogous to the Java Runtime Environment (JRE), which achieves this goal.

The CLR is Microsoft's intermediary between .NET developers' source code and the underlying hardware, and all .NET code ultimately runs within the CLR.

This CLR provides many exciting features not available in earlier versions of Windows DNA, such as automatic garbage collection, exception handling, cross-language inheritance, debugging, and "side-by-side" execution of different versions of the same .NET component.