Any Unix-like operating system needs a C library: the library which defines the ``system calls'' and other basic facilities such as open, malloc, printf, exit...
The GNU C Library is used as the C library in the GNU system and in GNU/Linux systems, as well as many other systems that use Linux as the kernel.
The GNU C Library is primarily designed to be a portable and high performance C library. It follows all relevant standards including ISO C11 and POSIX.1-2008. It is also internationalized and has one of the most complete internationalization interfaces known.
The current stable version of glibc is 2.22. See the NEWS file in the glibc sources for more information.
2015-08-14: glibc 2.22 released.
2015-02-06: glibc 2.21 released.
2014-09-07: glibc 2.20 released.
2014-02-08: glibc 2.19 released.
2013-08-12: glibc 2.18 released.
The history of Unix and various standards determine much of the interface of the C library. In general the GNU C Library supports the ISO C and POSIX standards. We also try to support the features of popular Unix variants (including BSD and System V) when those do not conflict with the standards. Different compatibility modes (selectable when you compile an application) allow the peaceful coexistence of compatibility support for different varieties of Unix.
The GNU C Library is currently maintained by a community of developers many of which are listed on the MAINTAINERS page of the project wiki.
Many others have contributed in large amounts as documented in the glibc Contributors.
Thank you to all who have contributed, either in bug reports, or by answering a question, your help is appreciated.