glibc

glibc, short for the GNU C Library, is the C standard library used by most GNU/Linux systems and many other Unix-like environments. It provides the core facilities that C programs rely on, including memory management, input/output, string handling, and mathematics, along with a wide range of system interfaces.

Beyond the ISO C interfaces, glibc implements POSIX and X/Open specifications and exposes Linux-specific extensions. It also includes support for localization and internationalization, threading with the POSIX threads library, dynamic loading, asynchronous I/O, and networking-related wrappers. The library is designed to be portable across a variety of hardware architectures and system configurations.

Glibc is developed and maintained by the GNU Project and a global community of contributors. The library is released under the GNU Lesser General Public License (LGPL) with a linking exception that permits linking with proprietary software, allowing wide use in both free and non-free products.

It is a core component of most GNU/Linux distributions and is used on other Unix-like systems such as the GNU Hurd. In certain environments, alternative C libraries such as musl or uClibc are used, particularly in lightweight or embedded systems.

History and influence: glibc originated in the 1990s as a successor to earlier GNU and BSD-derived C libraries and has since become the de facto standard C library on Linux, continually evolving to meet the needs of modern applications, languages, and system interfaces.