Berkeley Software Distribution License (BSD License)

An open-source license, which started to be used in the early 1980s by the University of California at Berkeley to distribute versions of the Berkeley Unix operating system as well as tools and applications. The license permitted widespread free copying and re-use of software, subject to acknowledging it as a creation of the University of California, Berkeley, acknowledgement of its copyright and non-use for promotional purposes. A similar license was also developed by the Massachusetts Institute of Technology known as the MIT license.  There are two extant versions of the BSD license supported by the Open Source Initiative, the 3-Clause License and the 2-Clause License.  The original version of the BSD license is now sometimes referred to as the 4-Clause BSD, particularly by the Free Software Foundation, who also call the 3-Clause License the Modified BSD License.