[Rd] forking a CRAN project

[Therneau, Terry M., Ph.D.]

Micheal,
   Keep in mind that the author of the package can give you a copy under any conditions 
that they choose, they are not bound by the GPL.  Simply send you code from their own 
source which is "upstream" of the GPL copy. (The copy out on CRAN propogates strictly via 
GPL however).  You could for instance start a new package de novo.
   This may or may not make sense in your case, but I wanted to point out the flexibility.

   A version of rpart has twice been bundled into commercial products via this route, 
where the user didn't want to be under the GPL.  None in the last 8-10 years; as Brian 
Ripley's and my contributions to rpart are now far too comingled to define a non-gpl code 
base.  I'll also note that in both those cases my employer took the quite defensible 
position that contributions to a for profit company are not free of charge.

On 03/05/2014 05:00 AM, r-devel-request at r-project.org wrote:
> There is a CRAN package licensed just as "GPL", say, XX, I want to use
> in a book.
> But I've needed to modify the package to make it do what I need for
> expository purposes.
> The package author(s) are amenable to my modifications, but probably
> unlikely to
> incorporate them into the CRAN version any time soon.
>
> Am I allowed, under GPL, to create a new version of the package, say
> XX2, in a
> public repository such as R-Forge or github?  I would, of course,
> maintain their
> authorship, though perhaps take over the maintainer role.  For my
> purposes in
> the book, I don't necessarily need to release my version to CRAN; just a
> public repo
> a reader could download from.
>
> -Michael