  BSD License Definition * <#disclaimer>

The /BSD license/ is a class of extremely simple and very liberal
licenses for computer software that was originally developed at the
University of California at Berkeley (UCB). It was first used in 1980
for the /Berkeley Source Distribution/ (BSD), also known as BSD UNIX, an
enhanced version of the original UNIX operating system that was first
written in 1969 by Ken Thompson at Bell Labs.

The only restrictions placed on users of software released under a
typical BSD license are that if they redistribute such software in any
form, with or without modification, they must include in the
redistribution (1) the original copyright notice, (2) a list of two
simple restrictions and (3) a disclaimer of liability. These
restrictions can be summarized as (1) one should not claim that they
wrote the software if they did not write it and (2) one should not sue
the developer if the software does not function as expected or as
desired. Some BSD licenses additionally include a clause that restricts
the use of the name of the project (or the names of its contributors)
for endorsing or promoting /derivative works/.

The most basic definition of a derivative work is a product that is
based on, or incorporates, one or more already existing works. This can
become a complex issue, particularly with regard to software, but the
primary indicator that a software program is a derivative of another
program is if it includes /source code/
<http://www.linfo.org/source_code.html> from the original program, even
if the source code has been modified, including improving, extending,
reordering or translating it into another programming language.

Source code is the version of software (usually an application program
or an operating system
<http://www.linfo.org/operating_systems_list.html>) as it is originally
/written/ (i.e., typed into a computer) by a human in /plain text/
<http://www.linfo.org/plain_text.html> (i.e., human readable alpha
<http://www.linfo.org/alphabet.html>numeric characters
<http://www.linfo.org/character.html>). Source code can be written in
any of hundreds of programming languages, some of the most popular of
which are C <http://www.linfo.org/c.html>, C++ and Java.

Due to the extremely minimal restrictions of BSD-style licenses,
software released under such licenses can be freely modified and used in
/proprietary/ <http://www.linfo.org/proprietary.html> (i.e., commercial)
software for which the source code is kept secret.

It is possible for a product to be distributed under a BSD-style license
and for some other license to apply as well. This was, in fact, the case
with very early versions of BSD UNIX, which included both new code
written at UCB and code from the original versions of UNIX written at
Bell Labs.

BSD-style licenses have been very successful, and they are now widely
used for a variety of software. Among the many products released under
this class of licenses are all of the major modern descendants of the
original BSD UNIX, i.e., FreeBSD, OpenBSD, NetBSD and Darwin (the
foundation of the Mac OS X). BSD-licensed software is also commonly
included in Linux <http://www.linfo.org/linuxdef.html> /distributions/
<http://www.linfo.org/distributions_list.html> (i.e., versions) and has
even been incorporated into some of the Microsoft Windows operating
systems.

*BSD Licenses Versus the GPL*

The GPL <http://www.linfo.org/gpl_text.html> (/GNU
<http://www.linfo.org/gnu.html> General Public License/) is by far the
most widely used license for /free software/
<http://www.linfo.org/free_software.html> (i.e., software whose source
code is available at no cost for anyone to use for any purpose). The
Linux /kernel/ <http://www.linfo.org/kernel.html> (i.e., the core of the
operating system) as well as much of the other software generally
included in Linux distributions have been released under the terms of
the GPL.

Although far fewer programs are released under BSD-style licenses, this
class of licenses is disproportionately important because of the
widespread use of BSD-licensed code in both free and proprietary
operating systems.

Possibly the biggest difference between the GPL and BSD licenses is the
fact that the former is a /copyleft/ license and the latter is not.
Copyleft is the application of copyright law to permit the free creation
of derivative works but requiring that such works be redistributable
under the same terms (i.e., the same license) as the original work.

Closely related to this is the fact that, in sharp contrast to the GPL,
BSD-style licenses do not require that derivative works based on
BSD-licensed software make the source code for such derivative works
freely available. This allows the direct incorporation of code from open
source projects (i.e., from BSD-licensed software) into closed source
projects. The GPL, however, specifically states: "This General Public
License does not permit incorporating your program into proprietary
programs."

A third difference is that the GPL is a single, copyrighted (by the Free
Software Foundation, Inc.) license with no variants. BSD-style licenses,
in contrast, are commonly modified for the specific situation.

In many cases, the use of open source code can allow companies to
develop products more quickly and with less expense than if they wrote
them with entirely original code. The fact that derivative products of
BSD-licensed software are not required to be open source can be very
useful for developers who want to create commercial products from open
source code but who want to keep their modifications and/or extensions
secret. Interestingly, companies that initially develop closed source
products based on BSD-licensed code tend to be more likely to eventually
make their source code publicly available than are companies that
develop products that do not incorporate code code.

The issue of which license provides greater freedom and does the most to
promote the development of improved software is highly controversial. In
spite of the seeming simplicity of the licenses, there are no simple
answers.

One of the most controversial properties of the GPL is its /viral/
nature. This means that once some useful modification or addition to a
GPL licensed program has been released, the source code of the modified
or extended program must likewise be made freely available. That is, the
GPL is a mechanism that deprives developers of the freedom to make their
source code secret at some future date, although the developer can still
use such code in commercial products. Critics of the GPL claim that this
diminishes or destroys the commercial value of software because others
can produce products that incorporate the same code.

GPL advocates claim that although the GPL is /contagious/ in theory, it
is not necessarily so in practice. Rather, they assert, it merely places
restrictions on the code's re-use, as do BSD-style licenses.

One thing about both the GPL and the BSD-style licenses for which there
is widespread agreement is that both have problems. Neither is perfect,
and perhaps no license can be perfect. There is also considerable
agreement that there are benefits both to software developers and to
society as a whole from the choice provided by the existence of a
variety of types of free software licenses, including the GPL and
BSD-style licenses.

*The "Advertising Clause"*

The original version of the BSD license contained the so called
/advertising clause/, which stated that all advertising materials that
mention features of or use of the software must display the
acknowledgment: "This product includes software developed by the
University of California, Berkeley and its contributors."

One of the problems with this clause arose from the fact that people who
made changes to the source code often wanted to have their names added
to the acknowledgment. This could easily result in large and cumbersome
acknowledgments for products with numerous contributors and for software
distributions consisting of multiple individual projects.

A second problem was legal incompatibility with the terms of the GPL.
This is because the GPL prohibits the addition of restrictions beyond
those that it already imposes. Thus it was necessary to segregate GPL
and BSD-licensed software within projects.

Initially, the "obnoxious BSD advertising clause," as it was referred to
by GPL advocates, was used only for the BSD UNIX license. That did not
cause any major problems because it was only necessary to include a
single sentence of acknowledgment in any advertisement.

However, the fact that other software developers did not copy the clause
verbatim, but replaced the phrase "University of California" with the
name of their own organization or persons involved in it, resulted in a
proliferation of slightly different licenses and a consequently serious
problem when many such programs were assembled to form a larger work or
an operating system. For example, if an operating system or other
program required fifty slightly different acknowledgment sentences, each
naming a different developer or group of developers, such /advertising/
alone might require a full page. Not only would this be very tedious
reading, but it could also be costly.

In June 1999, after two years of discussion, the Office of Technology
Licensing at UCB finally proclaimed: "Effective immediately, licensees
and distributors are no longer required to include the acknowledgment
within advertising materials. Accordingly, the foregoing paragraph of
those BSD Unix files containing it is hereby deleted in its entirety."

This was clearly very useful. However, it could not eliminate the legacy
of the advertising clause, as similar clauses still exist in the
licenses of many programs that followed the old BSD license; only the
developers of such packages can change them.

*Examples of BSD-Style Licenses*

Below are three examples of BSD-style licenses: (1) the BSD license as
it is used by the FreeBSD operating system, (2) a BSD license as it is
used by /Sudo/ (a free utility program for Unix-like
<http://www.linfo.org/unix-like.html> operating systems) and (3) a
template of a BSD-style license that can be applied to any appropriate
project:

(1) The BSD license as it is used by the FreeBSD Unix operating system:

    Copyright 1994-2004 The FreeBSD Project. All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    THIS SOFTWARE IS PROVIDED BY THE FREEBSD PROJECT "AS IS" AND ANY
    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
    PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FREEBSD PROJECT OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.

    The views and conclusions contained in the software and
    documentation are those of the authors and should not be interpreted
    as representing official policies, either expressed or implied, of
    the FreeBSD Project.


(2) The BSD-style license for Sudo, a small utility that allows
designated users to have temporary /root/ (i.e., administrative) access
to run specified privileged commands
<http://www.linfo.org/command.html>. This software, while released under
a BSD-style license, also incorporates other software that had earlier
been released under a BSD-style license (referred to below as a /UCB
license/) by UCB. Moreover, it contains a third condition, which
restricts the use of the name of the author for endorsements or
promotions of products derived from the software, and a fourth
condition, which restricts the use of the name of the software on
products derived from the software.

    Sudo License

    Sudo is distributed under the following BSD-style license:

    Copyright (c) 1994-1996,1998-2003 Todd C. Miller All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    3. The name of the author may not be used to endorse or promote
    products derived from this software without specific prior written
    permission from the author.

    4. Products derived from this software may not be called "Sudo" nor
    may "Sudo" appear in their names without specific prior written
    permission from the author.

    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
    WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
    IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
    OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
    AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    Sponsored in part by the Defense Advanced Research Projects Agency
    (DARPA) and Air Force Research Laboratory, Air Force Materiel
    Command, USAF, under agreement number F39502-99-1-0512.

    Additionally, lsearch.c, fnmatch.c, getcwd.c, snprintf.c
    strcasecmp.c and fnmatch.3 bear the following UCB license:

    Copyright (c) 1987, 1989, 1990, 1991, 1993, 1994 The Regents of the
    University of California. All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    3. Neither the name of the University nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS''
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
    PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.


(3) A template for a BSD-style license. [YEAR], [COPYRIGHT OWNER] and
[LICENSOR] are to be replaced by the actual year of copyright, the owner
of the copyright and the licensor. The copyright owner and licensor may
be the same, as in the case of the license for FreeBSD (as shown above).

    Copyright © [YEAR] [COPYRIGHT OWNER]. All Rights Reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
    notice, this list of conditions and the following disclaimer in the
    documentation and/or other materials provided with the distribution.

    3. The name of the author may not be used to endorse or promote
    products derived from this software without specific prior written
    permission.

    THIS SOFTWARE IS PROVIDED BY [LICENSOR] "AS IS" AND ANY EXPRESS OR
    IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
    GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
    IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
    OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
    IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


________

** Disclaimer:* The above material is presented for reference purposes
only, and it is not intended as nor does it constitute legal advice.
Neither Bellevue Linux nor any of its content providers shall be liable
for any errors or omissions in the content or for any actions taken in
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beyond that of an informed layman. Any questions should be referred to a
licensed attorney specializing in copyrights and intellectual property
law. Proper legal advice can only be provided by a licensed attorney
with reference to the specific facts of a particular situation and to
the laws of the relevant jurisdiction.






Created April 19, 2004. Updated April 22, 2005.
Copyright © 2004 - 2005 The Linux Information Project. All Rights Reserved.

	

