Windows Identity Foundation (WIF) 3.5 is a set of .NET Framework classes that can be used for implementing claims-based identity ...

Windows Identity Foundation (WIF) 3.5 is a set of .NET Framework classes that can be used for implementing claims-based identity in your .NET 3.5 and 4.0 applications. WIF 3.5 has been superseded by WIF classes that are provided as part of .NET 4.5. It is recommended that you use .NET 4.5 for supporting claims-based identity in your applications.