libstdc

libstdc++ is the GNU Standard C++ Library, the reference implementation of the C++ standard library shipped with the GNU Compiler Collection (GCC). It provides the runtime support for standard C++ language features, including input/output streams, containers and iterators, algorithms, strings, numerics, and utilities such as smart pointers, locale support, and threading primitives.

The library is designed to work with the application binary interface (ABI) defined by the corresponding GCC version and is released as part of GCC releases. libstdc++-v3 is the current incarnation, replacing older libstdc++ and delivering extended support for C++11 through C++20 (and newer drafts), alongside the libsupc++ support library used for low-level runtime components.

Licensing is the GNU General Public License with the GCC Runtime Library Exception, which permits linking libstdc++ into non-GPL software in typical usage. The project maintains broad portability across platforms, including Linux and other Unix-like systems, and Windows through GCC toolchains such as MinGW and MSYS2.

Development and maintenance are coordinated within the GCC project. Updates follow the evolution of the C++ standard, and ABI changes between major GCC releases are possible, though efforts are made to minimize disruption for existing code.

In practice, libstdc++ is the default C++ standard library on GCC-based toolchains and remains a mature, widely used implementation. It is often compared with and complemented by alternative C++ standard libraries such as libc++ from the LLVM project, which provides a separate implementation with different design goals.