This section describes interfaces that unmanaged hosts can use to integrate the common language runtime (CLR) in the .NET Framework version 4 and later into their applications. These interfaces provide methods for a host to configure and load the runtime into a process.
All .NET Framework 4 hosting interfaces have the following characteristics:
They use lifetime management (AddRef and Release), encapsulation (implicit context) and QueryInterface from COM.
There do not use COM types such as BSTR, SAFEARRAY, or VARIANT.
Provides methods that return a specific version of the CLR, list all installed CLRs, list all in-process runtimes, return the activation interface, and discover the CLR version used to compile an assembly.