BSD Licensing

BSD licenses were developed at UCB (University of California at Berkeley) and used for the first time for BSD (Berkeley Source Distribution) in 1980. Users of software that is under a BSD license have some simple restrictions. If the software is redistributed in any form, irrespective of any modification, redistribution must include the following 3 things:

  1. the original copyright notice
  2. two restrictions - (1) Do not claim authorship of the software if it is written by somebody else (2) do not take any legal action against the developer if the software does not perform as promised. Additionally, some licenses may have the clause that prohibits or limits using the project or its contributors’ names for endorsement of derivative works.
  3. a disclaimer of liability - Since BSD licenses have extremely few restrictions, software can be modified and used in commercial software. However, software which is distributed under a BSD license can still be subject to some other license,e.g. very early versions of BSD UNIX included both new code written at UCB and code from the original versions of UNIX written at Bell Labs

BSD License Vs GPL

GPL or GNU General Public License is the license that is used most widely for free software. Major software including the Linux kernel and other software included in Linux distributions have been released under the terms of the GPL. GPL and BSD licenses vary under several dimensions:

  1. GPL is a copyleft license, while BSD is not. Copyleft license implies the application of copyright law to permit the free creation of derivative works but it requires that the work should be redistributable under the same terms as the original work
  2. While the GPL license states that "This General Public License does not permit incorporating your program into proprietary programs," this is not the case with BSD licenses. BSD licenses have no need for derivative works based on BSD license to make the source code for such derivative works freely available. As a result of this code form open source projects can be incorporated into closed source projects
  3. Another difference is that while GPL is a single, copyrighted license having no variants, BSD-style licenses can be modified according to the specific situation

There has been a raging debate over which license provides more freedom and does the maximum to promote the development of improved software. BSD style licenses do not need to be open source which is helpful for developers who create commercial products from open source but do not want to disclose their modifications. GPL however, does not allow this. Critics of GPL claim that it deprives developers of the liberty to make their source code confidential at a later date, though (s)he can still use the code commercially. GPL’s supporters however, claim that GPL only places restrictions on the re-use of software code, like BSD licenses.

Critics and supporters of both licenses agree to the benefits to software developers from the choice provided by the existence of a variety of types of free software licenses.