The license stanza is not free-form. A single value must be chosen from a list of valid symbols.
The values for license are categories, rather than fully-specified licenses. For example, :gpl is a category; we do not distinguish between versions of the GPL. Similarly, :cc and :bsd comprise many variants. They must always pertain to the license of the software itself, not the vendor’s business model (a free app to access a paid service is still :gratis, not :freemium).
The license stanza is intended as an aid to search/filtering of Casks. For full and complete information, the user must always rely on the vendor’s homepage.
Note that brew cask search and brew cask list are not yet capable of using the information stored in the license stanza.
Cask authors should use the most specific license category which is also correct. Generic categories are provided for difficult cases. :unknown is also perfectly fine if you are unsure.
Example: Chromium includes code with multiple licenses, all of which are open source. Chromium licensing is described by the generic category :oss.
| symbol | meaning |
|---|---|
:oss |
open-source software |
:closed |
closed-source software |
:unknown |
license unknown |
:other |
license is known, but fits no category |
| symbol | generic category | meaning | URL |
|---|---|---|---|
:gratis |
:closed |
free-to-use, closed source | |
:commercial |
:closed |
not free to use | |
:freemium |
:closed |
free-to-use, payment required for full or additional functionality | http://en.wikipedia.org/wiki/Freemium |
:affero |
:oss |
Affero General Public License | https://gnu.org/licenses/agpl.html |
:apache |
:oss |
Apache Public License | http://www.apache.org/licenses/ |
:arphic |
:oss |
Arphic Public License | http://www.arphic.com/tw/download/public_license.rar |
:artistic |
:oss |
Artistic License | http://dev.perl.org/licenses/artistic.html |
:bsd |
:oss |
BSD License | http://www.linfo.org/bsdlicense.html |
:cc |
:oss |
Creative Commons License | http://creativecommons.org/licenses/ |
:eclipse |
:oss |
Eclipse Public License | https://www.eclipse.org/legal/eplfaq.php |
:gpl |
:oss |
GNU Public License | http://www.gnu.org/copyleft/gpl.html |
:isc |
:oss |
Internet Systems Consortium License | http://www.isc.org/downloads/software-support-policy/isc-license/ |
:lppl |
:oss |
LaTeX Project Public License | http://latex-project.org/lppl/ |
:ncsa |
:oss |
University of Illinois/NCSA Open Source License | http://otm.illinois.edu/uiuc_openSource |
:mit |
:oss |
MIT License | http://opensource.org/licenses/MIT |
:mpl |
:oss |
Mozilla Public License | https://www.mozilla.org/MPL/ |
:ofl |
:oss |
SIL Open Font License | http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=OFL |
:public_domain |
:oss |
not copyrighted | http://creativecommons.org/publicdomain/zero/1.0/legalcode |
:ubuntu_font |
:oss |
Ubuntu Font License | http://font.ubuntu.com/licence/ |
:x11 |
:oss |
X Consortium License | http://www.xfree86.org/3.3.6/COPYRIGHT2.html |