Jean-Michel FRANCOIS <[email protected]> writes: > Hi, > > I have a question regarding licensing of Plone addons. > > Context: The CMS Plone 4 is GPL v2 and is build upon Zope. > Zope is under ZPL license which is BSD-like > but it also adds clauses prohibiting trademark use and requiring > documentation of all changes. > Some core libraries of Plone are distributed under BSD license. > > I know I can't use GPLv3 for Plone addons (ie. Cyn.in can't be updated to > use Plone4)
Are you sure this is the reason it can't be updated? Both Plone 3[1] and 4[2] use GPLv2. > Now the questions: > > - Is there any default licensing for Plone addons? I don't think so, have you checked the site[3]? > - If I want to create a product a là Cyn.in do I need to publish > this project as GPLv2? As per the GNU compatibility matrix[4], you could also use GPLv2 or later. > - What is the GPL version when I just write "GPL"? (This is the > case for many Plone addons.) I looked briefly in the GNU Project's GPL FAQ and did not come up with a satisfactory answer to this. My recommendation is: - If you are writing the software, be explicit about the version and/or remember to include the license text (it is the recommended practice) - If someone else is the author look for the LICENSE or COPYRIGHT file. > - Can a Plone addon be licensed under the BSD license? IANAL, but I think it might be fine, as BSD is GPL-compatible. Also, look in the Plone License FAQ[5] under "Must add-on products for Plone be licensed under the GPL?". Regards, Servilio Footnotes: [1] https://github.com/plone/Plone/blob/3.3/docs/LICENSE.GPL This is just GPL-2 without preamble and the closing section on how to apply the license. [2] https://github.com/plone/Plone/blob/4.2.x/docs/LICENSE.GPL [3] http://plone.org/foundation/copyrights [4] http://www.gnu.org/licenses/gpl-faq.html#gpl-compat-matrix [5] http://plone.org/foundation/copyrights/license-faq _______________________________________________ Product-Developers mailing list [email protected] https://lists.plone.org/mailman/listinfo/plone-product-developers
