The GNU C Library

The project website can be found here:

The GNU C Library - The project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX.1-2008, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open, read, write, malloc, printf, getaddrinfo, dlopen, pthread_create, crypt, login, exit and more.

The GNU C Library is designed to be a backwards compatible, portable, and high performance ISO C library. It aims to follow all relevant standards including ISO C11, POSIX.1-2008, and IEEE 754-2008.

The project was started circa 1988 and is more than 30 years old. You can see the complete project release history on the wiki.

Despite the project's age there is still a lot to do so please Get Started and Get Involved!


The GNU C Library can be found on the main GNU ftp server (download glibc via HTTPSdownload glibc via HTTP or download glibc via FTP), and its mirrors; please use a mirror if possible.


Documentation for the GNU C Library is online, as is documentation for most GNU software. It can also be accessed by running info libc or man libc, or by looking at /usr/share/doc/glibc/, or similar directories on your system. A brief summary is available by running info libc.

Mailing lists

The GNU C Library has the following core mailing lists:

For more mailing lists please see the list of steps to get involved in glibc.

Announcements about the GNU C Library and most other GNU software are made on the info-gnu mailing list (archives).

Security reports that should not be made immediately public can be sent directly to the maintainers. If there is no response to an urgent issue, you can escalate to the general security mailing list for advice.

Getting involved

Development of the GNU C Library, and GNU in general, is a volunteer effort, and you can contribute. For information, please read How to help GNU. If you'd like to get involved, it's a good idea to join the discussion mailing list (see above).

Development tools
For development sources, issue trackers, and other information, please see the GNU C Library project page.
Trying the latest test release (when available) is always appreciated. Test releases can be found on the GNU “alpha” server (HTTPSHTTPFTP) and its mirrors.
To translate the program messages into other languages, please refer to the Translation Project page for the GNU C Library. New translations or updates to the existing strings will not be incorporated into the GNU C Library if they are sent elsewhere. For more information, see the Translation Project home page.
The GNU C Library is currently maintained by a group of stewards who support an even larger group of developers


The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.