The specification of the CLR is now embodied in the European Computer Manufacturers Association standard for the CLI, ECMA-335, and also in the equivalent ISO standard, ISO/IEC 23271, so the CLR is the implementation of this standard.This is the reason why C++ for CLR is referred to as C++/CLI.
For natively executing code, one possibility is to use MFC which encapsulates APIs which orginated long before C++ arrived on the secne, so it has none of OO characteristics that would be expected if it were written today. The ISO/ANSI standard is defined by the document ISO/IEC 14882 that is published by the American National Standards Institute. ISO/ANSI standard C++ is the well established version of C++.
