Next, a C++ Metro application will still load Win32 DLLs such as kernel32 and ntdll. Moreover, the WinRT APIs call into the Win32 DLLs so they are not a replacement but rather a wrapper, an API flavor, on top of Win32. (Historical note: Windows used to have a feature called “environment subsystems”, which can be roughly described as API flavors. WinRT is not an environment subsystem it is a library on top of the Win32 environment subsystem.)