The Microsoft .NET Framework 4 redistributable package installs the .NET Framework runtime and associated files that are required to run and develop applications to target the .NET Framework 4.

The .NET Framework is Microsoft's comprehensive and consistent programming model for building applications that have visually stunning user experiences, seamless and secure communication, and the ability to model a range of business processes.

The .NET Framework 4 works side by side with older Framework versions. Applications that are based on earlier versions of the Framework will continue to run on the version targeted by default.