Patent-Use 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.

GNU Affero General Public License v3.0

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

AGPL-3.0 is a strong copyleft license with one critical addition over GPL-3.0: offering the software over a network counts as “distribution.” Anyone who modifies the software and makes it available as a network service must make the complete corresponding source code available to users who interact with it.

This closes the “SaaS loophole” present in GPL-3.0, where a company can run a modified copy on its servers without ever distributing binaries and thus never triggering the copyleft requirement.

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.

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.

Server Side Public License v1.0

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

SSPL is MongoDB’s response to the AGPL “loophole”: if you offer the software as a managed service, you must also release under SSPL the source code of every program you use to offer that service — provisioning, monitoring, orchestration, backup. In effect, it is strong copyleft extended to your service stack.

The OSI rejected SSPL as not meeting the Open Source Definition, specifically on Criterion 6 (no discrimination against fields of endeavour). It is therefore fair-code / source-available, not open source.