Os on Your License

Apache License 2.0

Mon, 01 Jan 0001 00:00:00 +0000

Apache 2.0 is a permissive license similar in spirit to MIT but with two key additions: an explicit patent grant from contributors, and an explicit requirement to document significant changes. It does not grant trademark rights.

The patent grant makes Apache 2.0 preferable for projects with many contributors or corporate sponsors — it reduces the risk of patent lawsuits against downstream users. Apache 2.0 is not compatible with GPL-2.0, but is compatible with GPL-3.0 and later.

BSD 3-Clause License

Mon, 01 Jan 0001 00:00:00 +0000

BSD 3-Clause is a short, permissive license that adds one constraint MIT does not: you cannot use the names of the original authors or contributors to endorse or promote products derived from the software without specific written permission.

In practice, the rules are nearly identical to MIT. Choose BSD-3-Clause if the no-endorsement clause is important to you or your project has historical BSD heritage.

How to apply

Add a LICENSE file with the full BSD 3-Clause text at the root of your project, filling in the copyright owner and year.

GNU General Public License v3.0

Mon, 01 Jan 0001 00:00:00 +0000

GPL-3.0 is a strong copyleft license. Anyone who distributes the software, modified or not, must make the complete corresponding source available under GPL-3.0. It includes an explicit patent grant and patent-retaliation clause.

It also includes anti-tivoization provisions — you cannot distribute GPL-3.0 software on hardware that prevents users from installing modified versions.

Pick GPL-3.0 when you want to make sure derivative works stay open. Pick AGPL-3.0 if you also want to close the loophole where software offered as a network service is not considered “distributed”.

GNU Lesser General Public License v3.0

Mon, 01 Jan 0001 00:00:00 +0000

LGPL-3.0 is a “library” variant of GPL-3.0. If you modify the LGPL-3.0 library itself, your modifications must be released under LGPL-3.0. If you just use the library — link to it, call its APIs — your own code can stay under any license, even proprietary.

LGPL-3.0 is a good fit for reusable libraries where you want modifications to the library itself to stay open, but you are fine with the library being called from closed-source code.

ISC License

Mon, 01 Jan 0001 00:00:00 +0000

ISC is a permissive license produced by the Internet Systems Consortium. It is functionally identical to the simplified BSD license and the MIT license — use, modify, distribute, include the copyright notice — but uses even fewer words.

It is npm’s default license for new packages, which is why you’ll see it on a lot of small JavaScript libraries.

How to apply

Add a LICENSE file with the full ISC text, filling in the copyright year and holder.

MIT License

Mon, 01 Jan 0001 00:00:00 +0000

The MIT License is one of the shortest and most permissive open-source licenses. It lets anyone use, copy, modify, merge, publish, distribute, sublicense, and sell copies of the software, provided they include the original copyright notice and license text.

It is a good default for libraries and frameworks you want adopted as widely as possible. If you care about protecting against patent claims from contributors, consider Apache-2.0 instead — the patent grant is the main difference.

Mozilla Public License 2.0

Mon, 01 Jan 0001 00:00:00 +0000

MPL-2.0 applies copyleft at the file level: if you modify an MPL-2.0 file, that file stays under MPL-2.0, but new files can be under a different license. This makes it easier to combine MPL-2.0 code with proprietary code than GPL or LGPL.

It includes an explicit patent grant and retaliation clause. It is compatible with both GPL and Apache-style licenses, which makes MPL-2.0 a common choice for projects that want some copyleft protection without scaring off commercial users.