I. Overview

The BSD License (BSD) is the abbreviation of Berkeley Software Distribution. Many softwares were distributed under this license. Because the BSD originated from the University of California, Berkeley, the owner of the first released BSD is the Regents of the University of California. Due to the fact that quite a few programmers have amended the BSD for their own license use and have created the divergent versions of the BSD, these licenses are altogether referred to as the “BSD-style” licenses.

The first release of the BSD comprises four main clauses. Among them, the “advertising clause” has caused many users who have amended the source codes being listed on the acknowledgments, and were critized by the GNU Project for it has made the acknowledgments particularly lengthy and clumsy. Besides, it may be incompatible with the GPL. To respond to Richard Stallman’s criticism (the leader of the GNU Project and drafter of the GPL), official leader of the BSD –William Hoskins – has first deleted the advertising clause on July 22, 1999 and a lot of the BSD users have followed. After deletion, the BSD is called the 3-clause BSD, while the old version was referred to as the 4-clause BSD.

Compared to other licenses such as the GPL, the BSD is almost of no limitations. Therefore, it is also closer to the public domain.

 

II. Current Status

Most current uses have relied on the 3-clause BSD. Since the BSD may be modified to fit any practical needs, there are also a lot of BSD-style licenses.

So far, only NetBSD remained to use the 4-clause BSD. Some other programs, including the KDE, have been using the 2-clause BSD. The 2-clause BSD does not contain the advertising clause anymore, and has removed the limitation on copyright holder as the endosement. Such a 2-clause BSD is acturally functionally equivalent to the MIT license. FreeBSD is also licensed under the 2-clause BSD, but an additional announcement has been made to explain that the following contributors’s viewponts does not belong to the official FreeBSD Project.

III. Rights and Duties

  1. Rights

Any commercial or personal use is permitted.

  2. Duties

    (1) Redistributions of source code must retain the copyright notice as contained in the license.

    (2) Redistributions in binary form must reproduce the copyright notice as contained in the license.

    (3) Neither the name of the <ORGANIZATION> nor the names of its contributors may be used to endorse or promote products derived from the software without specific prior written permission. The <ORGANIZATION> case will depend on the user name of the BSD.

IV. Other Important Features

  1. The BSD license may coexist with other licenses.

  2. The BSD is a nearly public domain license. Any peroson or organzation are free to change the “University of California” sign to make the license more suitable for their own use.

  3. The BSD licensed softwares may be used at will, which means that both open source and proprietary softwares can use BSD licensed source code.

  4. The warranty clause is very simple.

  5. The 3-clause BSD License is approved as a free software license by the Free Software Foundation (FSF) and approved as an open source license by the Open Source Initiative (OSI). It is compatiable with the GPL.