IObjectContext - I
MTS defines an implementation of IObjectContext interface for each running object in the server.
IObjectContext interface contains CreateInstance() function and extends from IUnknown interface.
GetObjectContext() function in MTS gets the pointer to the IObjectContext interface if object defines this interface, then MTS does not need to provide a default one. Under the control of MTS, instantiation of an object should be done with CreateInstance function of IObjectContext interface instead of CoCreateInstance function since an object created from IObjectContext interface can inherit the activity, transaction, and security identities from the creator's context object.