Visualizza wikitesto di BSD licenses

{{Refimprove|date=February 2008}}{{Infobox software license
| name            = "New" BSD License
| image           = 
| caption         = The BSD daemon
| author          = [[Regents of the University of California]]
| version         = 
| copyright       = Public Domain
| date            = 1983<ref>{{cite web |url=http://www.lemis.com/grog/SCO/cringely.html |title=Robert Cringely's article about the SCO affair |author=Greg Lehey |date=2003-06-23 |accessdate=2007-11-25}}</ref>{{Dubious|Date of BSD license|date=May 2009}}
| OSI approved    = Yes
| Debian approved = Yes
| Free Software   = Yes
| GPL compatible  = Yes
| copyleft        = No
| linking         = Yes
}}

'''BSD licenses''' represent a family of [[permissive free software licence|permissive free software licenses]]. The original was used for the [[Berkeley Software Distribution]] (BSD), a [[Unix-like]] operating system after which the license is named. The original owners of BSD were the [[Regents of the University of California]] because BSD was first written at the [[University of California, Berkeley]]. The first version of the license was revised, and the resulting licenses are more properly called modified BSD licenses. [[Permissive license]]s, sometimes with important differences pertaining to [[license compatibility]], are referred to as "[[#BSD-style licenses|BSD-style licenses]]".  Several BSD-like licenses, including the New BSD license, have been [[vetting|vetted]] by the [[Open Source Initiative]] as meeting their definition of [[open source]].

The licenses have few restrictions compared to other free software licenses such as the [[GNU General Public License]] or even the default restrictions provided by [[copyright]], putting it relatively closer to the [[public domain]].

==Terms==
The typical BSD license contains 3 major clauses, allowing unlimited redistribution for any purpose as long as its copyright notices and the license's disclaimers of warranty are maintained. The license also contains a clause restricting use of the names of contributors for endorsement of a derived work without specific permission. Older versions of the BSD license however, contained an additional but controversial clause.

<pre>
Copyright (c) <year>, <copyright holder>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * 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.
    * Neither the name of the <organization> 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 <copyright holder> <nowiki>''AS IS''</nowiki> 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 <copyright holder> 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.
</pre>

=== UC Berkeley advertising clause ===

As originally distributed, the BSD license had an extra clause, requiring
authors of all works deriving from a BSD-licensed work to include an
acknowledgment of the original source.  This is numbered as clause 3 in the
original license text:

<pre>
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.
</pre>

This clause has been objected to on the grounds that as people changed the
license to reflect their name or organization it led to escalating advertising
requirements when programs were combined together in a software
distribution&mdash;every occurrence of the license with a different name
requires a separate acknowledgment&mdash; the [[Free Software Foundation]] has
cited the requirement for 75 such acknowledgments when advertising a 1997
version of [[NetBSD]].<ref name=GNU>{{cite web
|url=http://www.gnu.org/philosophy/bsd.html
|title=The BSD License Problem
|publisher=Free Software Foundation, Inc.
|accessdate=2006-11-15}}</ref>
In addition, it presents a legal problem for those wishing to publish
BSD-licensed software which relies upon separate programs using the
more-restrictive [[GNU General Public License|GPL]]: the advertising clause is
[[License compatibility|incompatible]] with the GPL, which does not allow the
addition of restrictions beyond those it already imposes.

The advertising clause was removed from the official BSD license text on
July 22, 1999 by William Hoskins, the director of the office of
technology licensing for Berkeley.<ref name=update>{{cite web
|url=ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
|title=To All Licensees, Distributors of Any Version of BSD
|publisher=University of California, Berkeley
|date=1999-07-22
|accessdate=2006-11-15}}</ref> Other BSD
distributions removed the clause, but many similar clauses remain in
BSD-derived code from other sources.

The original license is now sometimes called "BSD-old" or "4-clause BSD",
while the current revision of the BSD license is sometimes referred to by
names including "BSD-new", "revised BSD", or "3-clause BSD".

== Proprietary software licenses compatibility ==

The BSD License allows proprietary commercial use, and for the software released under the license to be incorporated into proprietary commercial products. Works based on the material may be released under a proprietary license or as closed source software.  This is the reason for widespread use of the BSD code in commercial products, ranging from [[Juniper Networks]] routers to [[Mac OS X]].<ref>{{cite web
|url=http://developer.apple.com/opensource/index.html
|title=Developer Connection &mdash; Open Source
|publisher=Apple, Inc.
|date=2007
|accessdate=2007-11-17
}}</ref>

It is possible for something to be distributed with the BSD License and some other license to apply as well. This was in fact the case with very early versions of BSD itself, which included proprietary material from [[AT&T]].

== BSD-style licenses ==<!-- This section is linked from [[Z shell]] -->
{{main|Permissive free software license}}
Several free or open source licenses that derive from or are similar to the BSD license are widely used:
* [[NetBSD]] switched from a 4-clause to a 2-clause BSD-like license [http://www.netbsd.org/about/redistribution.html#why2clause on June 20, 2008]; it removes the third (endorsement/promotion) clause.
* A 2-clause BSD-like license also exists which deletes the third clause, prohibiting use of the [[copyright]] holder's name for endorsement purposes.  Removal of that clause makes the license functionally equivalent to the [[MIT License]].  This is the only BSD-style license [http://developer.kde.org/policies/licensepolicy.html permitted] for certain libraries included in [[KDE]].  
* [[FreeBSD]] also uses a [http://www.freebsd.org/copyright/freebsd-license.html 2-clause license] with an additional statement at the end that the views of contributors are not the official views of the FreeBSD Project.
* [[FreeBSD]] also provides the [[FreeBSD Documentation License]], a license similar to the subsequent [[BSD Documentation License]] that contains terms specific to documentation.
* [[OpenBSD]] uses a license modeled after the [[ISC license]], "equivalent to a two-term BSD copyright with language removed that is made unnecessary by the Berne convention."<ref>OpenBSD's [http://www.openbsd.org/cgi-bin/cvsweb/src/share/misc/license.template?rev=HEAD license] and [http://www.openbsd.org/policy.html copyright policy].</ref>
* The [[MIT license]] is similar to the BSD license.
* The [[University of Illinois/NCSA Open Source License]] combines text from both the MIT and BSD licenses, and is equivalent to the 3-clause BSD license.
* The [[Xiph.Org Foundation]] uses the [http://www.xiph.org/licenses/bsd/ 3-clause license] for the binary libraries of their different projects without significant differences from the New BSD license.
* [[Microsoft]]'s [[Shared source#Microsoft Public License (Ms-PL)|Public License]]<ref>{{cite web |url=http://www.microsoft.com/resources/sharedsource/licensingbasics/sharedsourcelicenses.mspx |title=Shared Source Licenses |publisher=Microsoft |date=2005-10-18 |accessdate=2007-11-25}}</ref> is "much like a BSD-style license, except that it prohibits re-licensing if the code is distributed in source code form."<ref>{{cite web |url=http://software.newsforge.com/article.pl?sid=05/10/25/1917205&from=rss |title=Are Microsoft's new licenses open source? |author=Joe 'Zonker' Brockmeier |date=2005-10-26 |publisher=Linux.com |accessdate=2007-11-25}}</ref>

== See also ==
{{Portal|Free software|Free Software Portal Logo.svg}}
*[[Free software licence|Permissive and copyleft licenses]]

== References ==
{{reflist}}

== External links ==
* [http://www.opensource.org/licenses/bsd-license.php BSD License Template]
* [http://www.oreilly.com/catalog/opensources/book/kirkmck.html Marshall Kirk McKusick, ''Twenty Years of Berkeley Unix: From AT&T-Owned to Freely Redistributable'', in: Open Sources: Voices from the Open Source Revolution, O'Reilly 1999]
*[http://www.linfo.org/bsdlicense.html BSD License Definition] – by The Linux Information Project (LINFO)

{{FOSS}}

[[Category:Open source licenses]]
[[Category:Free software licenses]]
[[Category:BSD]]

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