World of licenses: dealing with BSD licenses

Recently, the World of Licenses article was written by me : we are working with the GNU GPL , in which I tried to summarize basic information about the GPL licenses, briefly describe the history of the license, its versions, and the compatibility of other licenses with the GPL. In the comments to the article there were several questions and, for answers to some of them, I made a partial translation of the official GPL FAQ.

As is often the case, the first article was the reason for the lengthy disputes, the essence of which boiled down to one question: "which is better (for people, programs, the world, the future) GPL or BSD license?". In my opinion, this dispute is akin to the question “from which end to break an egg?” And does not have one definite answer. The use of a certain license is the business of everyone and their diversity is only a positive factor that gives developers (and authors) more freedom and opportunities to distribute their works.

In this article I will try to consider the second side of the controversy - BSD licenses, their differences, history and derivatives. In addition, I will try to compare the GPL and BSD and explain why the original BSD license is incompatible with the GPL.
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UPD: the sections “Original BSD license” and “ISC license (OpenBSD license)” are updated

BSD

Probably everyone knows that BSD stands for “Berkeley Software Distribution”. This is the name of the software package assembled by Bill Joy, a graduate of the University of California Berkeley, as an annex to the sixth version of the UNIX operating system. In 1983, according to wiki, the 2.9BSD package was already not just a software package, but a full-fledged operating system, which is a modified UNIX v7. Thus, “BSD” has come to mean “BSD UNIX” and, in this sense, this abbreviation has survived to this day.

BSD licenses

A curious story is associated with the BSD license, a description of which is located here . In short, already 4.3BSD in 1986 contained references to the BSD license in the form of comments in the source code. But, for some reason, the license text itself was not attached to the project tree. And only 4.4BSD published in 1994 contained the full text of the original BSD license, which (according to the source) dates back to 1990.

However, another source reports that the license was used in 1980. Be that as it may, today there are several options for BSD licenses.

Original BSD license

This is the first version of the license, which is called the license of 4 points (by the number of points of conditions in the text). The license permitted the free use and distribution of source or binary codes with or without modifications, but with the conditions listed in these four paragraphs. These terms were :
1. Common copies of the source code must contain the copyrights listed above, this list of conditions and disclaimers listed below.
2. Common copies of a binary code must reproduce the copyrights listed above, this list of conditions and disclaimers listed below in the documentation and / or other materials supplied with the package.
3. All advertising materials referring to the possibilities or use of this software must demonstrate the following notice: This product includes software developed by the University of California, Berkeley and the people who helped. [1]
4. Neither the name of the University nor the names of the partners may be entered or used to promote products made on the basis of this software without special written permission.

This version of the license has been criticized by Richard Stallman, the author of the GPL license. Unfortunately, the third point led to the fact that different developers, releasing their products under the BSD license, replaced the words in it with their organization. Thus, the compilation of several, sometimes many, different parts of the code in one project resulted in a large list of mandatory references to the copyrights of various companies and developers when placing advertisements (there is information that the figure of such mandatory copyrights reached 75 pieces). It is because of the third point that the original BSD license is not compatible with GPL licenses and codes issued under it cannot be used in the GPL project.

Revisited BSD license

The problem with the third point was resolved in 1999, when on July 22, an appeal was issued by William Hoskins, director of the licensing department of the University of Berkeley, which canceled the third item of the license for all BSD products. According to this document, it was no longer necessary to include a link to the University of Berkeley in its promotional materials.

Thus, a revised BSD license has emerged, also known as the 3-point license. This license option became compatible with GPL licenses, which undoubtedly had important consequences. Now the codes of both licenses, put together, could be released in one product under one GPL license.

Clear BSD license

This type of license is based on the Revisited BSD license and contains one additional clause, which indicates that the license does not grant any rights to patents. Clear BSD was created by MetaCarta, which explains the modification by wanting to eliminate ambiguity with respect to patents in BSD licenses. The difference in licenses is in this line: "NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED BY THIS LICENSE." [2]. Clear BSD is compatible with GPLv2 and GPLv3.

FreeBSD license

This license is also known as a 2-point license. Compared to the modified BSD license, this license has removed the terms of the Berkeley University. The license was born during the development of the FreeBSD project - an operating system based on UNIX. The license is compatible with the GNU GPL.

ISC license (OpenBSD license)

In 1995, another variation of UNIX appeared, which the founders called OpenBSD . It was distributed using the license created by the Internet Software Consortium, which was similar to the two-point BSD license (FreeBSD), but essentially removed these two points, since according to the Bern Convention for the Protection of Literary and Artistic Works , which came into force in the USA March 1, 1989, they were no longer required. As a result, the license began to constitute, in addition to the disclaimer, a single sentence: all copies ". This simple license is compatible with GPL-licenses.

GPL and BSD, instead of a conclusion

In essence, all BSD licenses are not copyleft licenses . That is, they do not require a derived code to be free. All licenses, with the exception of the very first original, are compatible with GPL-licenses, but this does not prevent the debate about which form of licenses is better or worse, which license is more free or which has a better effect on the world and has a future.

The GPL and BSD personify two points of view on the free software world. The first one believes that software should be free and generate free software. “Freedom or Death” - Stallman’s slogan best reflects the meaning of this viewpoint. The second point of view suggests that freedom must also consist in making non-free software. This is a more liberal point of view. In essence, a philosophical question arises here: can permission to restrict freedom be considered freedom?

In fact, it is good that most developers are not addicted and approach the question simply: if they want to see parts of their software only in similar free products, then they choose the GPL, if they don’t care , they often choose the BSD license. It is the indifference to the fate of their software that characterizes the approach to freedom different from the GPL.

Personally, I do not see any contradictions to the fact that these two approaches exist simultaneously and are used by different developers. In my opinion, such a variety of approaches to the development and distribution of its software only reflects how diverse our world and its views are. The more views in society, the more polar and diverse, the more options there will be for licensing and distributing software. And this is great. Do not be conservatives, look at the world more widely, be tolerant and accept diversity as one of the properties of the surrounding world.

Sources

[1] BSD license
[2] The Clear BSD: Introduction

PS:
please, if you find an inaccuracy or an error in the article, please let us know in the comments or to my personal mail