In SEP 2013, Minimalist GNU for Windows (MinGW) was updated to version 4.8.1 of the GNU Compiler Collection (GCC).
MinGW: http://sourceforge.net/projects/mingw/
Changes to GCC 4.8 and GCC 4.8.1: http://gcc.gnu.org/gcc-4.8/changes.html
Changes to MinGW for GCC 4.8.1: http://sourceforge.net/projects/mingw/files/MinGW/Base/gcc/Version4/gcc-4.8.1-2/
MinGW also sports a new installer. As of this post, the current installer does not create a fstab file in C:\MinGW\msys\1.0\etc\, so you have to create one yourself that defines /mingw so that when you run C:\MinGW\msys\1.0\msys.bat, the prompt created will be able to find g++ in the /mingw/bin path.
Note: GCC 4.8.1 implements the entire C++11 language, but doesn’t yet support the entire C++11 library.
For Visual Studio, Microsoft is getting closer to releasing a compiler that supports most of the C++11 language. The Visual Studio 2013 Release Candidate can be downloaded here:
http://www.microsoft.com/visualstudio/eng/2013-downloads#d-2013-editions
… and can be read about here:
http://blogs.msdn.com/b/somasegar/archive/2013/09/09/announcing-the-visual-studio-2013-release-candidate.aspx
Note: Visual Studio 2013 implements the entire C++11 library, but doesn’t yet support the entire C++11 language.