Permissive
Usually allows use, modification and redistribution, including in commercial work, provided that the required copyright and licence notices are kept. Apache 2.0 also contains an express patent licence.
Open-source licence guide
This guide explains the main licence families used by tools in the library. Read the licence supplied with a tool before using, changing or redistributing it.
Weak copyleft
Allows use alongside differently licensed software, but changes to the covered library, file or component usually need to remain available under the same licence.
Strong copyleft
Redistributed versions and derivative works generally need to remain under the GPL, with corresponding source code made available.
Network copyleft
Builds on GPL obligations and can also require source availability when modified software is provided as a service over a network.
Public-domain style
Uses a broad dedication and fallback licence. Organisations should still check whether this approach is suitable in their jurisdiction.
Common licences
None / no licence specified NONEMIT License MITApache License 2.0 Apache-2.0BSD 2-Clause License BSD-2-ClauseBSD 3-Clause License BSD-3-ClauseISC License ISCGNU General Public License v2.0 GPL-2.0-onlyGNU General Public License v2.0 or later GPL-2.0-or-laterGNU General Public License v3.0 GPL-3.0-onlyGNU General Public License v3.0 or later GPL-3.0-or-laterGNU Lesser General Public License v2.1 LGPL-2.1-onlyGNU Lesser General Public License v3.0 LGPL-3.0-onlyGNU Affero General Public License v3.0 AGPL-3.0-onlyMozilla Public License 2.0 MPL-2.0Eclipse Public License 2.0 EPL-2.0The Unlicense Unlicense