BSD license

The BSD license is the license agreement that the BSD software (largely, a version of UNIX) is distributed under. The owner of the original BSD distribution was the "Regents of the University of California". This is because BSD originally came from the University of California, Berkeley.

Versions of the current BSD template (and the older version with the "advertising clause", see below) are often used by other organizations. The text of the license is considered to be in the public domain and thus may be modified without restriction to suit the needs of a particular individual or organization. This is because it was written before the Berne Convention was enacted in the United States, where the University of California is located.

The BSD License does not prohibit commercial use. Works based on the material may even be released under a proprietary license. Some notable examples of this are the use of BSD networking code in Microsoft products, and the use of numerous FreeBSD components in Mac OS X.

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 Unix itself, which included proprietary material from AT&T.

As originally distributed the license had an extra clause, the so called advertising clause:

     * 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.

The GNU project referred to it as the "obnoxious BSD advertising clause". Along with offending people, the clause caused a practical problem. People who made changes to the source code tended to want to have their names added to the acknowledgement. With large numbers of people working on a single project (or for many separate projects in a software distribution), the advertising clause quickly created large and unwieldy acknowledgements. Another practical problem was legal incompatibility with the terms of the GNU General Public License (which does not allow the addition of restrictions beyond those it already imposes), forcing a segregation of GNU and BSD software. The GNU project went so far as to suggest people not use the phrase "BSD-style" licensing when they wanted to refer to an example of a non-copyleft license, in order to prevent inadvertent usage of the original BSD license.

On July 22, 1999, William Hoskins, the director of the office of technology licensing for Berkeley, revoked the clause. The document enacting that revocation is available at <ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change>. The original license is now sometimes called "BSD-old" or "4-clause BSD", with the revised license sometimes called "BSD-new", "revised BSD", or "3-clause BSD". More often than not however, the revised license is called the "modern BSDL," or simply, the "BSDL."

However, NetBSD still uses a 4-clause license.

A 2-clause BSD-like license also exists; this version deletes the third (formerly fourth) clause, which prohibits use of the name of the copyright holder for endorsement purposes. This license is the official BSD License for projects included in KDE, according to this policy. 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.

Text of the original license (with advertising clause)

Many people discourage the use of the advertising clause (see above). This text is provided solely due to historical interest. Those intending to use the BSD License for their own projects are encouraged to consider using a modern 2- or 3-clause license instead of this one.

* 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.

See also

• BSD and GPL licensing
• FreeBSD Documentation License

External links

• BSD License Template
• The BSD License Problem (GNU Project)
• Materials about the Unix System Laboratories v. BSD case
• 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