The .NET Framework

The .NET Framework 3.0 is the latest version of Microsoft’s application development platform. It includes the Common Language Runtime (CLR), which is a software component for running and loading applications, and a set of class libraries-hierarchically organized collections of code that developers can use in their applications to present graphical UIs, access databases and files, and communicate over the Web.

The .NET Framework first shipped in early 2002 and was the most significant change in Microsoft’s development platform in nearly 10 years. It offered developers markedly better productivity through a combination of improved programming languages, a runtime environment that prevents many common programming mistakes, and a set of libraries of prewritten functionality that allows developers to focus more time on writing the code unique to their application instead of the “plumbing” code common to virtually all applications. Application code that runs under the control of the CLR is often referred to as “managed” code and is contrasted to “native” or “unmanaged” code.