unravelling the myth around open source licences - IViR

The Linux-kernel
An official version of the source code of the Linux kernel is made available via the website
kernel.org. Here the opportunity is given to download the software concerned without the prior need
to accept a certain agreement. The kernel is offered in source code in a compressed file. After being
uncompressed several directories are created in which parts of the kernel are placed, using names
such as lib, kernel and security.
In the top directory, there is a file named COPYING in which the GPL is included, with the
following addition at the beginning of the file:
‘NOTE! This copyright does *not* cover user programs that use kernel services by normal
system calls - this is merely considered normal use of the kernel, and does *not* fall under
the heading of “derived work”.
Also note that the GPL below is copyrighted by the Free Software Foundation, but the
instance of code that it refers to (the Linux kernel) is copyrighted by me and others who
actually wrote it.
Also note that the only valid version of the GPL as far as the kernel is concerned is - this-
particular version of the license (i.e. v2, not v2.2 or v3.x or whatever), unless explicitly
otherwise stated.
Linus Torvalds’.
A file called COPYING can also be found in the directory /fs/hfs (this contains the GPL). In
the directory arch/sparc/lib/ there is a file called COPYING.LIB that contains the LGPL. A file in
the directory sound/oss/ includes a file called COPYING containing the GPL.
The main directory contains a file called CREDITS listing the main contributors to the kernel.
The list is organised alphabetically based on the surnames of the contributors, whereby their name, email
address and a short description of the contribution are included. Apart from that, there is
another file called MAINTAINERS in which the names of those considered responsible for the
several kernel parts are mentioned. These people must be contacted should one wish to make a
contribution to that specific module. Finally, this directory contains a file called README giving a
concise description of the software and of the method to compile it. Under the heading ‘What is
Linux?’ mention is made, among other things, of its distribution under the GNU General Public
License.
The kernel consists of more than 12000 files, part of which is documentation. 98 Of the
approximately 12000 files, some 1311 files contain the term COPYING (the name of the file
containing the GPL). 99 In the ‘kernel’ directory containing system independent files, none of the 47
files refers to the GPL using the term COPYING. In the ‘lib’ directory, which also contains system
independent files, only 2 out of 40 files refer to the GPL using the term COPYING.
To examine each file with respect to the use of differently formulated references to the GPL
would go beyond the scope of this book, but we can safely conclude that not every kernel file
contains a GPL reference. Even in the more important code, such as the code in the lib directory,
references to the GPL cannot always be found. For some short three-sentence files this would not be
required since they are not original enough to enjoy copyright protection. Should they be compiled,
the GPL does not come into play.
98 The figure 12090 has been found by giving the command: ‘find * I grep-v ^d I wc-1’.
99 The figure has been found by giving the command: ‘grep -r COPYING * I wc -1’.
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