Microsoft Visual C++ (MSVC) is a compiler for the C, C++, C++/CLI and C++/CX programming languages by Microsoft. MSVC is proprietary software; it was originally a standalone product but later became a part of Visual Studio and made available in both trialware and freeware forms. It features tools for developing and debugging C++ code, especially code written for the Windows API, DirectX and .NET.

Many applications require redistributable Visual C++ runtime library packages to function correctly. These packages are frequently installed separately from the applications they support, enabling multiple applications to use the package with only a single installation. These Visual C++ redistributable and runtime packages are mostly installed for standard libraries that many applications use.

The predecessor to Visual C++ was called Microsoft C/C++. There was also a Microsoft QuickC 2.5 and a Microsoft QuickC for Windows 1.0. The Visual C++ compiler is still known as Microsoft C/C++ and as of the release of Visual C++ 2015 Update 2, is on version 14.0.23918.0.^{[citation needed]}

There are several different version numbers to consider when working with Visual C or C++. The oldest and most original of these is the compiler version number, which has been monotonically increased since the early Microsoft C compiler days. This is the version returned by running the command cl.exe on its own without any options. By taking two digits after the decimal and dropping the decimal point, this also becomes the value of the C pre-processor macro: _MSC_VER, and the CMake variable: MSVC_VERSION. A longer version of the C macro is _MSC_FULL_VER to make more finely-grained distinctions between builds of the compiler. An example of _MSC_VER is 1933 to represent version 19.33 of the Microsoft C/C++ compiler, and of _MSC_FULL_VER is 193331630.

The Visual product version, such as "17.3.4", designates the version of Visual Studio with which version 19.33 of the compiler was packaged. Then there is the Microsoft Visual C/C++ Runtime Library version, e.g. "14.3". From this, one can also deduce the toolset version, which can be obtained by taking the first three digits of the runtime library version and dropping the decimal, e.g. "143". It includes the Visual C/C++ runtime library, as well as compilers, linkers, assemblers, other build tools, and matching libraries and header files. The following is a (scrapeable) table of the known correlated version numbers.

The Visual C++ compiler ABI has historically changed between major compiler releases. This is especially the case for STL containers, where container sizes have varied a lot between compiler releases. Microsoft therefore recommends against using C++ interfaces at module boundaries when one wants to enable client code compiled using a different compiler version. Instead of C++, Microsoft recommends using C or COM interfaces, which are designed to have a stable ABI between compiler releases.

All 14.x MSVC releases have a stable ABI, and binaries built with these versions can be mixed in a forwards-compatible manner, noting the following restrictions:

Visual C++ ships with different versions of C runtime libraries. This means users can compile their code with any of the available libraries. However, this can cause some problems when using different components (DLLs, EXEs) in the same program. A typical example is a program using different libraries. The user should use the same C Run-Time for all the program's components unless the implications are understood. Microsoft recommends using the multithreaded, dynamic link library (/MD or /MDd compiler option) to avoid possible problems.