http://openbsd.org/

OpenBSD* Copyright Policy
________________________________________
-	Goal
Copyright law is complex, OpenBSD* policy is simple - OpenBSD strives to maintain the spirit 
of the original Berkeley Unix copyrights.
OpenBSD can exist as it does today because of the example set by the Computer Systems Research 
Group at Berkeley and the battles which they and others fought to create a relatively 
un-encumbered Unix source distribution.
The ability of a freely redistributable "Berkeley" Unix to move forward on a competitive 
basis with other operating systems depends on the willingness of the various development 
groups to exchange code amongst themselves and with other projects. Understanding the legal 
issues surrounding copyright is fundamental to the ability to exchange and re-distribute code, 
while honoring the spirit of the copyright and concept of attribution is fundamental to 
promoting the cooperation of the people involved.
-	The Berkeley* Copyright
The Berkeley* copyright poses no restrictions on private or commercial use of the software 
and imposes only simple and uniform requirements for maintaining copyright notices in 
redistributed versions and crediting the originator of the material only in advertising.
For instance:
 * Copyright (c) 1982, 1986, 1990, 1991, 1993
 *	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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
Berkeley rescinded the 3rd term (the advertising term) on 22 July 1999. Verbatim copies 
of the Berkeley license in the OpenBSD tree have that term removed. In addition, many 
3rd-party BSD-style licenses consist solely of the first two terms.
Because the OpenBSD copyright imposes no conditions beyond those imposed by the Berkeley 
copyright, OpenBSD can hope to share the same wide distribution and applicability as the 
Berkeley distributions. It follows however, that OpenBSD cannot include material which 
includes copyrights which are more restrictive than the Berkeley copyright, or must 
relegate this material to a secondary status, i.e. OpenBSD as a whole is freely 
redistributable, but some optional components may not be.
-	Copyright Law
While the overall subject of copyright law is far beyond the scope of this document, some 
basics are in order. Under the current copyright law, copyrights are implicit in the 
creation of a new work and reside with the creator, unless otherwise assigned. In general 
the copyright applies only to the new work, not the material the work was derived from, 
nor those portions of the derivative material included in the new work.
Copyright law admits to three general categories of works:
Original Work
A new work that is not derived from an existing work.
Derivative Work
Work that is derived from, includes or amends existing works.
Compilations
A work that is a compilation of existing new and derivative works.
The fundamental concept is that there is primacy of the copyright, that is a copyright of a 
derivative work does not affect the rights held by the owner of the copyright of the original 
work, rather only the part added. Likewise the copyright of a compilation does not affect the 
rights of the owner of the included works, only the compilation as an entity.
It is vitally important to understand that copyrights are broad protections as defined by 
national and international copyright law. The "copyright notices" usually included in source 
files are not copyrights, but rather notices that a party asserts that they hold copyright 
to the material or to part of the material. Typically these notices are associated with 
license terms which grant permissions subject to copyright law and with disclaimers that 
state the position of the copyright holder/distributor with respect to liability surrounding 
use of the material.
-	Permissions - the flip side
Because copyrights arise from the creation of a work, rather than through a registration process, 
there needs to be a practical way to extend permission to use a work beyond what might be allowed 
by "fair use" provisions of the copyright laws.
This permission typically takes the form of a "release" or "license" included in the work, which 
grants the additional uses beyond those granted by copyright law, usually subject to a variety of 
conditions. At one extreme sits "public domain" where the originator asserts that he imposes no 
restrictions on use of the material, at the other restrictive clauses that actually grant no 
additional rights or impose restrictive, discriminatory or impractical conditions on use of the 
work.
Again, an important point to note is that the release and conditions can only apply to the 
portion of the work that was originated by the copyright holder - the holder of a copyright 
on a derivative work can neither grant additional permissions for use of the original work, 
nor impose more restrictive conditions for use of that work.
Because copyright arises from the creation of a work and not the text or a registration process, 
removing or altering a copyright notice or associated release terms has no bearing on the 
existence of the copyright, rather all that is accomplished is to cast doubt upon whatever rights 
the person making the modifications had to use the material in the first place. Likewise, adding 
terms and conditions in conflict with the original terms and conditions does not supersede them, 
rather it casts doubts on the rights of the person making the amendments to use the material and 
creates confusion as to whether anyone can use the amended version or derivatives thereof.
Finally, releases are generally binding on the material that they are distributed with. This means 
that if the originator of a work distributes that work with a release granting certain permissions, 
those permissions apply as stated, without discrimination, to all persons legitimately possessing 
a copy of the work. That means that having granted a permission, the copyright holder can not 
retroactively say that an individual or class of individuals are no longer granted those permissions. 
Likewise should the copyright holder decide to "go commercial" he can not revoke permissions already 
granted for the use of the work as distributed, though he may impose more restrictive permissions in 
his future distributions of that work.
-	Specific Cases
This section attempts to summarize the position of OpenBSD relative to some commonly encountered 
copyrights.
Berkeley*
The Berkeley copyright is the model for the OpenBSD copyright. It retains the rights of the 
copyright holder, while imposing minimal conditions on the use of the copyrighted material. 
Material with Berkeley copyrights, or copyrights closely adhering to the Berkeley model can 
generally be included in OpenBSD.
AT&amp;T*
As part of its settlement with AT&amp;T*, Berkeley included an AT&amp;T copyright notice on some of the 
files in 4.4BSD lite and lite2. The terms of this license are identical to the standard Berkeley 
license.
Additionally, OpenBSD includes some other AT&amp;T code with non-restrictive copyrights, such as the 
reference implementation of awk.
Caldera*
Caldera* (now known as the SCO group) is the current owner of the Unix code copyrights. On 23 
January 2002, the original Unix code (versions 1 through seven, including 32V) was freed by Caldera. 
This code is now available under a 4-term BSD-style license. As a result, it is now possible to 
incorporate real Unix code into OpenBSD (though this code is quite old and generally requires significant 
changes to bring it up to date).
DEC*, Sun*, other manufacturers/software houses.
In general OpenBSD does not include material copyrighted by manufacturers or software houses. 
Material may be included where the copyright owner has granted general permission for reuse 
without conditions, with terms similar to the Berkeley copyright, or where the material is the 
product of an employee and the employer's copyright notice effectively releases any rights they 
might have to the work.
Carnegie-Mellon* (CMU, Mach)
The Carnegie-Mellon copyright is similar to the Berkeley copyright, except that it requests that 
derivative works be made available to Carnegie-Mellon. Because this is only a request and not a 
condition, such material can still be included in OpenBSD. It should be noted that existing 
versions of Mach are still subject to AT&amp;T copyrights, which prevents the general distribution 
of Mach sources.
Apache*
The original Apache* copyright is similar to the Berkeley copyright, except that it stipulates 
that products derived from the code may not have "Apache" in their name. The purpose of this 
clause is to avoid a situation in which another party releases a modified version of the code 
named in such a way to make users think that it is the "official" version. This is not an issue 
with OpenBSD because OpenBSD is a Compilation, and not a Derived Work. Source code published under 
version 2 of the Apache license cannot be included into OpenBSD. As a consequence, OpenBSD now 
maintains its own version of Apache based on version 1.3.29. The OpenBSD version includes many 
enhancements and bugfixes.
ISC*
The ISC* copyright is functionally equivalent to a two-term BSD copyright with language removed 
that is made unnecessary by the Berne convention. This is the preferred license for new code 
incorporated into OpenBSD. A sample license is included in the source tree as 
/usr/src/share/misc/license.template.
GNU* General Public License, GPL, LGPL, copyleft, etc.
The GNU* Public License and licenses modeled on it impose the restriction that source code must 
be distributed or made available for all works that are derivatives of the GNU copyrighted code.
While this may be a noble strategy in terms of software sharing, it is a condition that is 
typically unacceptable for commercial use of software. As a consequence, software bound by the 
GPL terms can not be included in the kernel or "runtime" of OpenBSD, though software subject to
 GPL terms may be included as development tools or as part of the system that are "optional" as 
long as such use does not result in OpenBSD as a whole becoming subject to the GPL terms.
As an example, GCC and other GNU tools are included in the OpenBSD tool chain. However, it is 
quite possible to distribute a system for many applications without a tool chain, or the 
distributor can choose to include a tool chain as an optional bundle which conforms to the 
GPL terms.
NetBSD*
Much of OpenBSD is originally based on and evolved from NetBSD*, since some of the OpenBSD 
developers were involved in the NetBSD project. The general NetBSD license terms are compatible 
with the Berkeley license and permit such use. Material subject only to the general NetBSD license 
can generally be included in OpenBSD.
In the past, NetBSD has included material copyrighted by individuals who have imposed license 
conditions beyond that of the general NetBSD license, but granted the NetBSD Foundation license 
to distribute the material. Such material can not be included in OpenBSD as long as the conditions 
imposed are at odds with the OpenBSD license terms or releases from those terms are offered on a 
discriminatory basis.
FreeBSD*
Most of FreeBSD* is also based on Berkeley licensed material or includes copyright notices based 
on the Berkeley model. Such material can be included in OpenBSD, while those parts that are subject 
to GPL or various individual copyright terms that are at odds with the OpenBSD license can not be 
included in OpenBSD.
Linux*
Most of Linux* is subject to GPL style licensing terms and therefore can not be included in 
OpenBSD. Individual components may be eligible, subject to the terms of the originator's copyright 
notices. Note that Linux "distributions" may also be subject to additional copyright claims of the 
distributing organization, either as a compilation or on material included that is not part of the 
Linux core.
X*, XFree86*, X.Org*
X*, X.Org* or XFree86* are not parts of OpenBSD, rather X.Org and parts of XFree86 3.3.6 are 
distributed with many OpenBSD ports as a convenience to the user, subject to applicable license 
terms.
Shareware, Charityware, Freeware, etc.
Most "shareware" copyright notices impose conditions for redistribution, use or visibility that 
are at conflict with the OpenBSD project goals. Review on a case-by-case basis is required as to 
whether the wording of the conditions is acceptable in terms of conditions being requested vs. 
demanded and whether the spirit of the conditions is compatible with goals of the OpenBSD project.
Public Domain
While material that is truly entered into the "Public Domain" can be included in OpenBSD, review 
is required on a case by case basis. Frequently the "public domain" assertion is made by someone 
who does not really hold all rights under Copyright law to grant that status or there are a variety
of conditions imposed on use. For a work to be truly in the "Public Domain" all rights are abandoned 
and the material is offered without restrictions.