GNU/Linux is the term used by the GNU project and its supporters, in particular its founder and main activist Richard Stallman, to refer to the UNIX-like operating system that is more commonly known as the Linux operating system or simply as Linux.
Linux is a Unix-like kernel written by Linus Torvalds and others. The GNU project had been begun in 1984 to develop a complete operating system based on free software. By 1991, when Linux was written, the GNU project had produced many of the components of this system, including a shell, a C library, and a C compiler. The core of the OS, the kernel, was incomplete, however.
Torvalds and other early Linux developers adapted the GNU components to work with the Linux kernel, creating a completely functional operating system. However, although the Linux kernel is licensed under the GNU General Public License, it is not part of the GNU project.
The name "GNU/Linux" was first used by Debian in 1994 as the name of their OS distribution based on the Linux kernel and GNU programs. (In 1992, The Yggrasil distribution was called Linux/GNU/X).
In GNU's 1994-June Bulletin, Linux is referred to as a "free UNIX clone" [with many GNU utilities and libraries]. In the 1995-January edition, the references to Linux were changed to "GNU/Linux".
In May of 1996, Richard Stallman released Emacs 19.31, changing the system target "Linux" to "Lignux". He argued that to give rightful credit to GNU, it is proper to use the terms "Linux-based GNU system", "GNU/Linux system", or "Lignux" to refer to the combination of the Linux kernel and the GNU system.
The requests to call the system "GNU/Linux" have met with mixed success at best. Only a few distributions have followed the lead of Debian in calling their systems "GNU/Linux". The corporate world, including most media outlets, do not. Amongst the users and developers in the free software and open source movements, some have followed this request; many others have ignored or opposed it.
Some consider the term "operating system" to refer to only the kernel, while the rest are simply utilities (regardless of the practical necessity and volume of such utilities). In this sense, the operating system is called Linux, and a Linux distribution is based on Linux with the addition of the GNU tools. On the other hand, both the name GNU and the name Linux are intentionally parallel to the name Unix, and Unix has always referred to the C library and userland tools as well as the kernel. (The latter is also closer to the popular understanding of the term "operating system" among the general public, who would never consider a bare kernel as such.)
Some of the reasons people refer to the system as "Linux" are:
- It is shorter and thus easier to say.
- Torvalds, the creator of the Linux kernel, has referred to the combined system solely as Linux from the time of its initial release in 1991.
- Stallman only began asking people to call the system "GNU/Linux" in the mid 1990s, after the system had become popular.
One practical problem with the use of the word "Linux" to refer to both the kernel and the distributions as a whole is that it has often led to confusion in the popular media (and hence among the general public), who e.g. frequently report that the entire operating system (in the popular sense) was written from scratch by Torvalds in 1991, that Torvalds directs the development of other components such as graphical interfaces, or that new releases of the kernel involve a similar degree of user-visible change to new major versions of proprietary operating systems such as Windows.
See also:
References:
- http://www.gnu.org/gnu/linux-and-gnu.html -- Linux and the GNU Project, by Richard Stallman
- http://www.slashdot.org/articles/99/04/09/1516203.shtml -- A debate on Slashdot on the name issue