Microsoft .NET Framework Redistributable Package

The Microsoft .NET Framework 3 is the new managed code programming model for Windows. It combines the power of the .NET Framework version 2 with new technologies for building applications that have visually compelling user experiences, seamless communication across technology boundaries, and the ability to support a wide range of business processes. These new technologies are Windows Presentation Foundation, Windows Communication Foundation, Windows Workflow Foundation, and Windows CardSpace.

The .NET Framework 3 is included as part of the Windows Vista operating system; you can install it or uninstall it using Windows Features Control Panel.