BSD licenses
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| Author | Regents of the University of California |
|---|---|
| Publisher | Public Domain |
| Published | 1983[1][dubious ] |
| DFSG compatible | Yes |
| Free software | Yes |
| OSI approved | Yes |
| GPL compatible | Yes |
| Copyleft | No |
| Linking from code with a different license | Yes |
BSD licenses represent a family of 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 licenses, sometimes with important differences pertaining to license compatibility, are referred to as "BSD-style licenses". Several BSD-like licenses, including the New BSD license, have been 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.
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[edit] 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.
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> ''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 <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.
[edit] UC Berkeley advertising clause
Older versions of the BSD license contained an additional clause, known as the "advertising clause", that eventually became controversial. It required authors of all works deriving from a BSD-licensed work to include an acknowledgment of the original source. This was clause number 3 in the original license text:
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.
This clause was 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—every occurrence of the license with a different name required a separate acknowledgment— the Free Software Foundation has cited the requirement for 75 such acknowledgments when advertising a 1997 version of NetBSD.[2] In addition, the clause presented a legal problem for those wishing to publish BSD-licensed software which relies upon separate programs using the more-restrictive GPL: the advertising clause is 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.[3] 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".
[edit] Proprietary software licenses compatibility
The BSD License allows proprietary use, and for the software released under the license to be incorporated into proprietary 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 proprietary products, ranging from Juniper Networks routers to Mac OS X.[4]
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.
[edit] BSD-style licenses
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 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[citation needed]. This is the only BSD-style license permitted for certain libraries included in KDE.
- FreeBSD also uses a 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."[5]
- 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 3-clause license for the binary libraries of their different projects without significant differences from the New BSD license.
- Microsoft's Public License[6] is "much like a BSD-style license, except that it prohibits re-licensing if the code is distributed in source code form."[7]
[edit] See also
[edit] References
- ^ Greg Lehey (2003-06-23). "Robert Cringely's article about the SCO affair". http://www.lemis.com/grog/SCO/cringely.html. Retrieved 2007-11-25.
- ^ "The BSD License Problem". Free Software Foundation, Inc.. http://www.gnu.org/philosophy/bsd.html. Retrieved 2006-11-15.
- ^ "To All Licensees, Distributors of Any Version of BSD". University of California, Berkeley. 1999-07-22. ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change. Retrieved 2006-11-15.
- ^ "Developer Connection — Open Source". Apple, Inc.. 2007. http://developer.apple.com/opensource/index.html. Retrieved 2007-11-17.
- ^ OpenBSD's license and copyright policy.
- ^ "Shared Source Licenses". Microsoft. 2005-10-18. http://www.microsoft.com/resources/sharedsource/licensingbasics/sharedsourcelicenses.mspx. Retrieved 2007-11-25.
- ^ Joe 'Zonker' Brockmeier (2005-10-26). "Are Microsoft's new licenses open source?". Linux.com. http://software.newsforge.com/article.pl?sid=05/10/25/1917205&from=rss. Retrieved 2007-11-25.
[edit] External links
- BSD License Template
- 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
- BSD License Definition – by The Linux Information Project (LINFO)
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