LGPLv2+ and LGPLv2+ with exceptions and GPLv2+ and GPLv2+ with exceptions and BSD and Inner-Net-2.0 and ISC and Public Domain and GFDL-1.3-only
The GNU C Library 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.
acquired package info from repodata DB: repodata/18c2be42fe2b5b288fc0e4628777cec64a6dd8c9b9c960757aa68407d41ebc3f-primary.sqlite.bz2
gdk is a multi-platform toolkit for creating graphical user interfaces.
gdk is written in C but has been designed from the ground up to support a wide range of languages. It provide a complete set of widgets,and suitable for projects ranging from small one-off tools to complete application suites.
GTK+ can use the cache files created by gtk-update-icon-cache to avoid alot of system call and disk seek overhead when the application starts.Since the format of the cache files allows them to be mmap()ed shared between multiple applications,the overall memory consumption is reduced as well.
The core library that forms the basis for projects such as GTK+ and GNOME
GLib is a bundle of three (formerly five) low-level system libraries written in C and developed mainly by GNOME. GLib's code was separated from GTK, so it can be used by software other than GNOME and has been developed in parallel ever since.