Microsoft was one of the first to implement a wide variety of C++11 features in their standard library and in their compiler, which made it harder to then port

Microsoft was one of the first to implement a wide variety of C++11 features in their standard library and in their compiler, which made it harder to then port it to Mac OS X/Linux due to the fact that the standard library had not yet yet caught up there. Now the shoe is on the other foot.