What is the BSD License? Top 10 questions answered

The University of California, Berkeley, has long been at the forefront of the computer sciences. The first computer mouse hailed from there in the 1950s, engineered by Douglas Engelbart. UC Berkeley is where Steve Wozniak and Steve Jobs met, although the latter was still in high school at the time.

In the 1980s, the university created an Operating System (OS) based on the original UNIX developed by Bell Labs. The Berkeley Software Distribution (BSD) OS was widely adopted by workstation vendors, with companies creating proprietary variants. The BSD license used in the OS makes it possible to share and distribute the source code freely at a time where copyrighting software had become the norm.

A BSD 3 clause license replaced the 4-Clause BSD License as the advertising clause in the previous version had become controversial. Specifically, the advertising clause was incompatible with the GNU General Public License (GPL), leading to the university publishing the New BSD License (or 3-Clause BSD License) in 1999.

Since its first use in the BSD OS, the BSD License can now refer to anyone in a family of BSD Free and Open Source Software (FOSS) licenses. One variant known as the Prior BSD License first appeared in 1988, but the 4-Clause BSD License from 1990 is widely accepted as the original BSD license. The 4-Clause BSD License required users to include the copyright notice in other distributions, while repaying the original contributors and mandating acknowledgments on all documentation, including advertising materials.

What are the terms of a BSD license?

Due to the different variants of the BSD license, it’s advisable to stipulate which license applies explicitly to the software. The terms of the New BSD License (or 3-Clause BSD License) requires users to:

• Retain the copyright notice, list of conditions, and the disclaimer on all redistributions of the source code.

• Reproduce the copyright notices, list of conditions, and the disclaimer on all documentation or any other material accompanying the distribution.

• Not use the name of the organization or contributors in the copyright notice to endorse or promote products without written permission.

The final section of the license provides a disclaimer that indemnifies the organization or contributors from any implied warranties.

What class is BSD License referred to?

FOSS licenses come in two main classes, namely copyleft or BSD-style and permissive licenses. Permissive licenses (which include the 3-Clause BSD License) place minimal restrictions on how other users can modify, use, or redistribute the source code (primarily only requiring attribution and indemnification).

What are the benefits of the BSD License?

With limited restrictions placed on the use, modification, and redistribution of BSD-licensed software, it’s popular with teams that have specific goals in mind. Long-term research projects or development environments that have little cost usually opt for permissive licenses like the New BSD license.

Can the BSD License be used commercially?

The main difference between copyleft licenses and permissive licenses is regarding subsequent distribution. With permissive licenses, there is no clause requiring the user to distribute the source code (which is the cornerstone of copyleft). As long as the developers include the original copyright and attributions in the software, they can redistribute variants commercially without also shipping the source code.

How do you get a BSD License?

To use the BSD license, users need to include it in the compiled version of the code and all associated documentation and other materials. In development environments like Github, create a new file and name it LICENSE. Choose the BSD License template, click on review and submit, and finally commit the file. It’s that easy.

Is BSD 3 License free?

Any user or team can use the BSD license by copying the original text and updating the information to reflect the owners, organizations, and copyright year. There are no additional licensing fees required.

Which popular software is released under a BSD license?

BSD licenses are popular and used on many projects, ranking as the sixth most popular license on Github in 2015. Some of the major open-source software still using BSD includes FreeBSD, DragonFly BSD, Google’s Bionic, and Darwin (which forms the foundation of macOS). Some Windows components also use BSD licensed software, like the TCP/IP protocols.

What are the other BSD licenses available?

After the 3-Clause BSD License, new variants have also become available. The 2-Clause BSD License, also published in 1999 by the FreeBSD project, removed both the promotion and advertising clauses from the 4-Clause BSD. Another variant is the Zero Clause BSD, which only has the copyright notices and disclaimer, without requiring the acknowledgment or redistribution of the copyright notice.

Is the 3-Clause BSD License compatible with GPL?

Removing the advertising clause from the 4-Clause BSD License makes the 3-Clause BSD License (and subsequent FreeBSD and Zero Clause BSD) compatible with GPLv3 licenses. Users can also combine software licensed under the 3-Clause BSD terms with other software licenses, but should always check compliance requirements for works that use multiple components licensed under different types of agreements.

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