What is GNU?

The GNU Project, pronounced “guh-noo”, was launched in
1984 by Richard Stallman to develop a complete UNIX style
operating system which is comprised of free software: the GNU
system.Variants of the GNU operating system, which use the
Linux kernel, are now widely used;though these systems are
often referred to as “Linux,” they are more accurately called
GNU/Linux systems.

The system's basic components include the GNU Compiler
Collection (GCC), the GNU Binary Utilities (binutils), the bash
shell,the GNU C Library (glibc),GNU Core Utilities (coreutils),
GNU Emacs Text Editor and GNOME Desktop Environment.
Presently, about 400 add-on packages are available from the
developer website.

Its official kernal, GNU Hurd, is incomplete and not all GNU
components work with it. Thus, the third-party Linux kernel is
most commonly used instead.But this kernel has not been
officially adopted by the GNU project.

Many GNU programs have also been ported to numerous other
operating systems such as Microsoft Windows, Solaris, Mac OS etc.