[R-pkg-devel] Changing License

[Dirk Eddelbuettel]

On 30 August 2018 at 08:34, Charles Determan wrote:
| It has come to my attention that some of the code I am distributing in one
| of my packages was previously licensed under the MIT license.  I have
| previously released my package under the GPL-3 license.  Would it be more
| appropriate for me to change the license to MIT?  I know no one here is
| likely a lawyer but I would like to hear if there is any issue in changing
| a license of a currently released package as it is my understanding that my
| package should have the MIT license instead.

It is my understanding that this is "additive" where licenses are compatible.

Look eg at R itself. It is under GPL-2+ but contains code from other folks
released under compatible licenses -- as document more precisely in this file

  https://github.com/wch/r-source/blob/trunk/doc/COPYRIGHTS

which enumerates which files (or sets of files and directories) have
different copyrights as well as licenses (these terms frequently get mangled,
this file does too).

As another reference point, Debian formalised something similar in the
prescribed format for debian/copyright files (typically installed as
/usr/share/doc/${PACKAGE}/copyright for a given package) where sets of files
are enumerated and both the copyright and license are stated.  See eg

  https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/

for all the gory details.

So in short, I think you can simply include a file stating which of the files
you re-use are copyrighted by which authors and released under which
license. _Your work extending and using those files_ as contained in your
package can happily remain under GPL-3 as does the aggregation, while the
components your refer to remain in eg MIT.

Makes sense?

Dirk
#notALawyerDisclaimerIfYouNeedIt

-- 
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