This section describes the interfaces that unmanaged hosts can use to integrate the common language runtime (CLR) into their applications.
The .NET Framework version 2.0 hosting interfaces supersede the .NET Framework version 1.0 and 1.1 interfaces. There are significant differences between the two sets of interfaces. Mixing them could cause unexpected behavior and is not recommended.
The .NET Framework versions 3.0 and 3.5 use the .NET Framework version 2.0 hosting interfaces, and do not introduce any hosting features.
The .NET Framework 4 hosting interfaces supersede the .NET Framework 2.0 interfaces. You should also familiarize yourself with the information presented in the Hosting Overview.