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 most systems with the Linux kernel.
The GNU C library is primarily designed to be a portable and high performance C library. It follows all relevant standards (ISO C 99, POSIX.1c, POSIX.1j, POSIX.1d, Unix98, Single Unix Specification). It is also internationalized and has one of the most complete internationalization interfaces known.
The current stable version of GLIBC is 2.14. See the NEWS file in the glibc sources for more information.
2012-01-03: Trunk open for 2.16 development.
2011-12-26: Trunk tagged for 2.15 release.
2011-06-07: Trunk open for 2.15 development.
2011-06-07: GLIBC 2.14 released.
2011-05-31: Trunk tagged for 2.14 release.
2011-05-08: Testing starts for 2.14.
2011-02-04: GLIBC 2.13 released.
2011-01-17: Trunk tagged for 2.13 release.
2010-05-20: GLIBC 2.11.2 released.
2010-05-13: Trunk tagged for 2.12 release.
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 was originally written primarily by Roland McGrath <roland@gnu.org> when he worked for the FSF. In 2001 The GNU C Library Steering Committee <glibc-sc@gnu.org>, was formed and currently consists of Mark Brown, Paul Eggert, Andreas Jaeger, Jakub Jelinek, Roland McGrath and Andreas Schwab. Ulrich Drepper is currently the foremost contributor and has overall responsibility for maintenance and development.
Many others have contributed in large amounts as documented in the glibc Contributors.