- :unknown
- No license specified.
- :custom
- A license text is going to be specified by the developer.
- :gpl-2-0
- The GNU General Public License, version 2.0.
- :gpl-3-0
- The GNU General Public License, version 3.0.
- :lgpl-2-1
- The GNU Lesser General Public License, version 2.1.
- :lgpl-3-0
- The GNU Lesser General Public License, version 3.0.
- :bsd
- The BSD standard license.
- :mit-x11
- The MIT/X11 standard license.
- :artistic
- The Artistic License, version 2.0.
- :gpl-2-0-only
- The GNU General Public License, version 2.0 only.
- :gpl-3-0-only
- The GNU General Public License, version 3.0 only.
- :lgpl-2-1-only
- The GNU Lesser General Public License, version 2.1 only.
- :lgpl-3-0-only
- The GNU Lesser General Public License, version 3.0 only.
- :agpl-3-0
- The GNU Affero General Public License, version 3.0 or later.
- :agpl-3-0-only
- The GNU Affero General Public License, version 3.0 only.
- :BSD-3
- The 3-clause BSD licence. Since 3.24
- :APACHE-2-0
- The Apache License, version 2.0. Since 3.24
- :MPL-2-0
- The Mozilla Public License, version 2.0. Since 3.24