Open Source License List
The 16 most-used licenses, grouped into permissive, weak copyleft, strong copyleft and public domain. Each page covers the obligations, common misconceptions and compatibility with other licenses.
Permissive
Licenses you can freely use even in closed-source products, as long as you keep the notices.
MITMIT LicenseThe most widely used short permissive license — you can do anything as long as you keep the copyright notice and permission notice.Apache-2.0Apache License 2.0A permissive license with an express patent grant and rules for NOTICE files and marking changes. Especially common in corporate projects.BSD-3-ClauseBSD 3-Clause "New" or "Revised" LicenseA permissive license that requires keeping notices when distributing source and binaries and not using the copyright holder's name to promote derived products without permission.BSD-2-ClauseBSD 2-Clause "Simplified" LicenseA two-clause permissive license that only requires keeping the copyright notice, conditions and disclaimer when distributing source and binaries.ISCISC LicenseA short permissive license with the same effect as MIT and BSD 2-Clause, in even fewer words.BSL-1.0Boost Software License 1.0A permissive license that requires notices only when distributing source, with no notice obligation for compiled binaries.
Weak copyleft
Only changes to the covered files or library must be published; other code that uses them can be licensed freely.
LGPL-3.0GNU Lesser General Public License v3.0A weak copyleft: changes to the library itself must be published, but apps that use the library can stay closed.LGPL-2.1GNU Lesser General Public License v2.1The 1999 weak copyleft for libraries. Apps that use it can stay closed, and the code can be converted to GPL-2.0 or any later version.MPL-2.0Mozilla Public License 2.0A file-level copyleft: only modified MPL files must be published, and the rest of the code can be under any license. It can also be combined with the GPL.EPL-2.0Eclipse Public License 2.0A business-friendly weak copyleft: EPL code and modifications must be published, but code written as separate modules can be under a commercial license.
Strong copyleft
Licenses that require the entire derivative work to be released with source under the same license.
GPL-3.0GNU General Public License v3.0A strong copyleft requiring the entire program distributed in combination to be released with source under the GPL. Adds a patent grant and an installation information clause.GPL-2.0GNU General Public License v2.0A strong copyleft from 1991 used by the Linux kernel and Git. When used as "only", it is incompatible with GPL-3.0 and Apache-2.0.AGPL-3.0GNU Affero General Public License v3.0The strongest copyleft — GPL-3.0 plus Section 13, which makes letting users interact with the program over a network trigger the obligation to provide source.
Public domain / no conditions
The least restrictive choices, which do not even require a copyright notice.
0BSDBSD Zero Clause LicenseA permissive license close to public domain that does not even require a copyright or license notice.UnlicenseThe UnlicenseA license that dedicates code to the public domain and substitutes an unconditional permission where the dedication is not recognized.CC0-1.0Creative Commons Zero v1.0 UniversalA declaration waiving copyright and related rights to the maximum extent permitted by law. Widely used for data and documents, but patent rights are excluded from the waiver.