The GNU C Library version 2.43 is now available (opens in new tab)

Fri Jan 23 23:18:41 GMT 2026

The GNU C Library
=================

The GNU C Library version 2.43 is now available.

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 C23 and POSIX.1-2024.  It is also
internationalized and has one of the most complete
internationalization interfaces known.

The GNU C Library website is at http://www.gnu.org/software/libc/

Packages for the 2.43 release may be downloaded from:
http://ftpmirror.gnu.org/libc/
http://ftp.gnu.org/gnu/libc/

The mirror list is at http://www.gnu.org/order/ftp.html

Distributions are encouraged to track the release/* branches
corresponding to the releases they are using.  The release
branches will be updated with conservative bug fixes and new
features while retaining backwards compatibility.

NEWS for version 2.43
=====================

Major new features:

* The ISO C23 free_sized, free_aligned_sized, memset_explicit, and
memalignment functions have been added.

* As specified in ISO C23, the assert macro is defined to take variable
arguments to support expressions with a comma inside a compound
literal initializer not surrounded by parentheses.

* For ISO C23, the functions bsearch, memchr, strchr, strpbrk, strrchr,
strstr, wcschr, wcspbrk, wcsrchr, wcsstr and wmemchr that return
pointers into their input arrays now have definitions as macros that
return a pointer to a const-qualified type when the input argument is
a pointer to a const-qualified type.

* The ISO C23 typedef names long_double_t, _Float32_t, _Float64_t, and
(on platforms supporting _Float128) _Float128_t, introduced in TS
18661-3:2015, have been added to <math.h>.

* The ISO C23 optional time bases TIME_MONOTONIC, TIME_ACTIVE, and
TIME_THREAD_ACTIVE have been added.