Work by dot.Net 1.1

The Microsoft .NET Framework is a software framework that can be installed on computers running Microsoft Windows operating systems. It includes a large library of coded solutions to common programming problems and a virtual machine that manages the execution of programs written specifically for the framework. The .NET framework supports multiple programming languages in a manner that allows language interoperability, whereby each language can utilize code written in other languages; in particular, the .NET library is available to all the programming languages that .NET encompasses. The .NET Framework is a Microsoft offering and is intended to be used by most new applications created for the Windows platform.

http://msdn.microsoft.com/netframework