Microsoft C++ Runtime -

And when main() returns? The process reverses. The CRT calls atexit handlers and destructs your static objects before returning control to the OS.

At its core, the Microsoft C++ Runtime is a library (or a set of libraries) that provides the fundamental building blocks for your C++ code. The C++ language standard defines features—like std::vector , std::cout , and new / delete —but the language itself doesn't know how to talk to the operating system. microsoft c++ runtime