In June of last year we published a pair of articles discussing the major changes that we had made to the Visual C++ C Runtime (CRT) for Visual Studio 2015. In "The Great C Runtime (CRT) Refactoring" we explained the major architectural changes that we had made to the CRT. In "C Runtime (CRT) Features, Fixes, and Breaking Changes in Visual Studio 14 CTP1" we enumerated all of the notable features we'd implemented and behavioral changes that we'd made.

Read the source article at MSDN Blogs