BSD 3-Clause License Generator

The BSD 3-Clause License explained

The BSD 3-Clause License — also called the New BSD License, Modified BSD License or simply "BSD" — is a short, permissive open-source license derived from the original Berkeley Software Distribution licenses. It is OSI-approved, classified by the FSF as a GPL-compatible free software license, and identified in SPDX as BSD-3-Clause.

Compared to BSD 2-Clause, it adds one extra clause: "Neither the name of [project] nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission." Plus the usual two conditions (preserve notice in source and binary) and a strong WARRANTY DISCLAIMER.

Projects that use it

BSD-3 is the default license of the scientific Python stack: NumPy, SciPy, pandas, scikit-learn and Matplotlib. It also covers PostgreSQL, the early Go (Golang) compiler, Django (mostly BSD-3), Twisted and Webpack. PostgreSQL's choice was strategic — it deliberately allows derivatives like Amazon RDS without forcing them to open-source.

BSD-3 vs BSD-2 vs MIT vs Apache 2.0

• BSD-3 vs BSD-2 — BSD-3 protects trademark/endorsement explicitly; BSD-2 does not. Think of BSD-3 as "BSD-2 plus a no-endorsement clause".
• BSD-3 vs MIT — BSD-3 is roughly "MIT + a no-endorsement clause". Useful when you want forks but not "endorsed by [you]" marketing.
• BSD-3 vs Apache 2.0 — Apache 2.0 is far more explicit about patent grants, requires a NOTICE file and includes a patent retaliation clause. BSD-3 is silent on patents.
• BSD-3 vs BSD-4 — the older BSD-4-Clause (Original BSD) had an "advertising clause" that made it GPL-incompatible and noisy in marketing materials. It was removed in 1999.

How to apply BSD-3

Drop a LICENSE file at the repository root containing the full text and your copyright line. Add the SPDX header // SPDX-License-Identifier: BSD-3-Clause at the top of each source file so tools like GitHub's license detector, FOSSA and ScanCode auto-identify it. Some BSD-3 projects (e.g. Google's Go) require contributors to sign a CLA — decide upfront whether you want that overhead.

FAQ

Does BSD-3 protect my project's name? Yes — clause 3 prohibits using the project or contributor names to endorse derivatives without written permission. This is the main differentiator from BSD-2 and MIT.

Can I use BSD-3 code in commercial products? Yes — including proprietary closed-source products, as long as the copyright notice and license text are preserved.

Can I advertise "based on [BSD-3 project]"? Only with explicit permission from the project owners. Pure factual statements ("uses PostgreSQL internally") generally fall outside the clause, but marketing-style endorsements do not.

Does BSD-3 require a CLA? No — the license itself does not. But many BSD-3 projects (Go, Django) adopt CLAs independently to ease relicensing or assert provenance.

Disclaimer. This generator produces a license template — it is not legal advice. For commercial products or trademark-sensitive projects, consult an attorney.