The BSD license, short for Berkeley Software Distribution license, is a permissive open-source license that allows users to freely use, modify, and distribute software. Originating from the University of California, Berkeley, it was created to enable a wide range of software sharing while imposing minimal restrictions on how the code can be used. Unlike more restrictive licenses, such as the GNU General Public License (GPL), the BSD license does not require derivative works to also be open-sourced. This makes it attractive for both academic and commercial developers who seek flexibility in how they can use software.
The BSD license has several variations, with the most commonly used being the two-clause and three-clause licenses. The two-clause version is quite simple: it permits users to do nearly anything with the software as long as the copyright notice and a disclaimer of warranty are included. The three-clause variant adds a restriction that prohibits the use of the names of the original authors or organizations behind the software for promotional purposes without permission. These licenses are straightforward, allowing developers to incorporate BSD-licensed code into their projects with ease, which encourages collaboration and sharing in the software development community.
Many popular software projects and libraries employ the BSD license. For example, the FreeBSD operating system, which significantly influenced many other systems, is distributed under this license. Additionally, projects like the Apache web server and the SQLite database also use BSD-compatible licenses. These examples illustrate how the BSD license fosters an environment where developers can build upon existing technologies while keeping their own projects flexible and proprietary if desired. This has made it a preferred choice for various organizations, promoting innovation while respecting intellectual property.