There are many faces of Linux, a term which has come to mean many things. Underneath all the things that Linux is, it is an operating system kernel.
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Figure 1. A somewhat simplified, logical cross-section of a Linux-based computer system.
Please see Anatomy of a Linux Distribution in our article SCO Clears Linux Kernel but Implicates Red Hat and SuSE. for the details, an explanation, and a bigger figure.
There are many faces of Linux. Underneath all the things that Linux is, it is an operating system kernel.
The term Linux also is applied to the popular GNU operating system built on top of the Linux kernel, simply the Linux OS. Then on top of that are the Linux-based distributions, such as Fedora, Mandriva, Red Hat, or SUSE, which wear many faces too.
Don't forget the controversy about calling the Linux-based operating system GNU/Linux. ". . . this system is basically the GNU operating system, with Linux added." (Richard M. Stallman) On the other hand, the people at Linux International say that Linux is an operating system, not just the Linux kernel:
Add to all this the recent endeavors of Linus Torvalds to enforce his Linux trademark. These trademark enforcement endeavors appear to be directed to applying the term Linux to all that stuff that is built on top of the Linux kernel.
Maybe it is time to be more careful about how we use the term Linux. Time to make it clear when one is referring to the Linux kernel, the GNU/Linux operating system, a Linux-based desktop, a Linux-based distribution, or whatever.
Linux-based distributions perhaps could have names such as SUSE OS, a Linux-based GNU operating system, or The Mandriva Linux-based GNU OS. Those of course would be the more formal names. In short, they still would simply be called Mandriva or SUSE, or perhaps Mandriva OS and SUSE OS.
Of course it is up to the distributors of Linux-based products to select and to promote the names for their products. And hopefully they will do that using the guidelines suggested here.
On the other hand: people like to use the name they like to use, whether it is correct or not. "Linux" rolls off the tongue. It is cute . . . I like the term "Linux", and I like cute penguins, and I hope that everyone continues to use them . . . Richard [Stallman] calls it "GNU/Linux". Linus calls it "Linux". I call it "Linux" . . . it is what I (and a lot of other people) have always called it. I like the term "Linux", and I like cute penguins, and I hope that everyone continues to use them. Jon "maddog" Hall.
Linux Trademark Note:
Please see the links in the Resources section on page 3 to the statements made to the Linux Kernel Mailing List, lkml, by Linus Torvalds regarding the necessity and rational of his enforcing the Linux trademark.
Incidentally, there has been some controversial coverage of the Linux trademark enforcement efforts recently. What Linus Torvalds says in his statements about that makes lots of sense to us.
Under the Linux Faces
The term Linux also is applied to the popular GNU operating system (OS) built on top of the Linux kernel, often simply called the Linux OS. Then on top of that are the Linux-based distributions that usually and simply are called Linux distributions, such as Mandriva Linux, Red Hat Linux, or SUSE Linux. Please see Figure 1 in the right sidebar
There are lots of Linux-based, operating system, distributions and they wear many faces too.
- Some are command-line only Linux-based OS distributions.
- Some are developed specially for server platforms.
- Some are designed for GUI desktop use.
- Yet others combine command-line, server, desktop, and enterprise functionality into a single Linux-based OS distribution package.
One problem with all this nomenclature is that it is very confusing. How do you know when someone says Linux if they are talking about:
- the kernel,
- the operating system,
- the desktop,
- a distribution,
- or whatever?
Of course the context in which Linux is used helps to let you know which of these many faces of Linux is the one to which reference is made.
The GNU and Linux Controversy
Don't forget all the controversy about calling the Linux-based operating system GNU/Linux. The Free Software Foundation people, that's Richard Stallman and the GNU people, say that the Linux-based operating system in use today should be called GNU/Linux.
That's because much of the software that surrounds the Linux kernel to make it an operating system is GNU software, which it is by the way. Please see Figure 1 in the right sidebar.
However, Richard Stallman (rms) disagreed with our characterization of FSF's position in an e-mail discussion:
Richard M. Stallman: Actually no, that is not what we say. What we say is that this system is basically the GNU operating system, with Linux added.
Please see the GNU Note in the right sidebar on page 2 for more about this.
Is Linux More than Merely a Kernel?
On the other hand, the people at Linux International say that Linux is an operating system, not just the Linux kernel:
Linux is an Operating System, which acts as a communication service between the hardware (or physical equipment of a computer) and the software (or applications which use the hardware) of a computer system. (What is Linux?, Linux International Website. Link in the Resources section at the end of the article on page 3.)
The people at kernel.org seem to go even further into using Linux to mean more than just the kernel, using the term Linux system:
the kernel . . . is just a component in a working Linux system. (New to Linux?, The Linux Kernel Archives. Link in the Resources section at the end of the article on page 3.)
Jon "maddog" Hall is a well-known Linux advocate, speaker, author, and also the Executive Director of Linux International (LI). We discussed that LI definition of Linux and other issues covered in this article with Jon while preparing this article. He noted:
Jon "maddog" Hall: When I first got involved with "Linux", people just called the whole OS (or for that matter the whole distribution) "Linux". "Give me that Linux CD", was the phrase, whether the CD included MySQL(TM), Postgres(TM), or the X Window System(TM). It was not "Linux International" who started calling the whole distribution "Linux". That was happening before LI was even created in 1994. The community was calling it that.
Linux Trademark Issues
Add to all this the recent endeavors of Linus Torvalds to enforce his Linux trademark. These trademark enforcement endeavors appear to be directed to applying the term Linux to all that stuff that is built on top of the Linux kernel, not to the kernel itself. Please see the Linux Trademark Note in the right sidebar.
During our discussions about the issues covered in this article with Jon "maddog" Hall, he further clarified the Linux trademark issues:
The trademark enforcement is not "directed" at anything other than the use of the term "Linux" in a name. However the creator of the name in question used the word "Linux" in a product name, then they should at least have given proper attribution to the "Linux" part, and they may have to sublicense it.
If you called your database the "Linux Relational Database", then we would ask you to give proper attribution to the word "Linux" and sublicense the use of the Linux name. So the trademark endeavors have nothing to do with the actual code or what the name really refers to .... it is just that someone decided to use the name, and they should properly attribute the owner. If they make money off the name, they should help to defend the Mark by sub-licensing it.