> So the question is: MS created both Windows and Visual Studio. So why can't Visual Studio compile to something that works by default on the Windows of the tar

> So the question is: MS created both Windows and Visual Studio. So why can't Visual Studio compile to something that works by default on the Windows of the target audience without requiring them to install those additional DLLs? Because msvcrt.dll must be compatible with MSVC6 or something ridiculous like that (the amd64 version probably needs to be ABI compatible with a different version, because MSVC6 didn't have amd64). They want to maintain backwards compatibility with existing software, so they can't change the ABI around. You might think, who cares about old software? Well, last I checked MinGW links against msvcrt.dll as well, so to provide compatibility with them (and probably software built today with the MinGW toolchain) they still need to keep it around and compatible. This is analogous to running with really old glibc… even that had a soname bump (it's not at 1 anymore). Can't exactly add symbol versioning either, since 1) it needs to support older versions of Windows, 2) people could totally roll their own dynamic loader… PE isn't exactly secret. For your last paragraph, as I understand it the Windows team basically uses their own fork of the toolchain, stuck bring binary compatible…