[Developers] ADMB-IDE licensing

[Arni Magnusson]

All right, here are some references I have found regarding licensing of 
aggregates that include GPL components. I'm assuming everyone on 
developers at admb-project.org is interested in how these things work, and 
I'm also hoping that some of you understand this better than I do. Please 
let me know if your interpretation of the licenses differs from mine.


[1] https://stat.ethz.ch/pipermail/r-help/2006-May/106245.html

The dicussion following the GPL licensing of glmmADMB highlights the main 
issue, even though ADMB has gone open source since that discussion.

ADMB uses BSD to allow users to release models as proprietary executables. 
When this is done, it must be made clear to all recipients that they are 
not allowed to bundle that executable inside a GPL package. Any package 
user can then insist to have the source code for the executable, so it 
would lose its proprietary status.

An important question is whether ADMB users are allowed to bundle BSD 
executables inside a GPL package. The knee-jerk response is no, but I'm 
not so sure. If glmmADMB is released as a GPL package today, then R users 
have the right to see, modify, and share source code - meaning the TPL and 
C++ code, even of ADMB itself. What they cannot is to alter the BSD 
license of that model (since it does not call R), much less of ADMB 
itself.

This is walking on a thin line that we need to understand fully. What is 
your understanding of this issue? This is not relevant for ADMB-IDE, by 
the way, as shown below.


[2] http://www.gnu.org/licenses/gpl-faq.html#MereAggregation

The ADMB-IDE installer is an aggregate, distributing separate programs 
together in one installer archive. The GPL permits me to create and 
distribute an aggregate, even when the licenses of the other software are 
non-free or GPL-incompatible.

The only condition is that I cannot release the installer under a license 
that prohibits users from exercising rights that each program's individual 
license would grant them. This means that ADMB, GCC, and Emacs must 
include their original licence text inside each directory.


[3] http://www.gnu.org/licenses/gpl-faq.html#GPLCompatInstaller

The license of the installation software does affect the installed
components, any more than a zip file would.


[4] http://www.gnu.org/licenses/gpl-faq.html#NonFreeTools

Which programs you use to edit the source code, or to compile it, or study 
it, or record it, usually makes no difference for issues concerning the 
licensing of that source code. In other words, it's nobody's business 
whether you use Emacs with ADMB-IDE, Notepad, diff, Visual C++, or any 
other other programs to work with ADMB code.


[5] http://www.gnu.org/licenses/gpl-faq.html#CanIUseGPLToolsForNF

Using Emacs, GCC, or other GPL programs to write and compile code does not 
place any license restrictions on the code or executables.


[5] http://www.gnu.org/licenses/gpl-faq.html#GPLModuleLicense

My admb-mode and .emacs components call Emacs and therefore need to be 
GPL-compatible. Potential licenses include GPL, LGPL, and BSD.


[6] http://opensource.org/licenses/gpl-3.0.html#section4

GPL legalese, saying that my distribution of Emacs and GCC is called 
"conveying verbatim copies". The original license text should be intact 
inside their directories.


[7] http://opensource.org/licenses/gpl-3.0.html#section5

GPL legalese, where the last paragraph rephrases item [2].


[8] http://opensource.org/licenses/gpl-3.0.html#section6

GPL legalese, where option 6b says I should indicate where GCC and Emacs 
can be downloaded in source code form. That's ftp://ftp.gnu.org/gnu/emacs/ 
and ftp://ftp.gnu.org/gnu/gcc/.

---

In short, it looks like I can distribute the simple click'n'go installer, 
where each component has its own license. I don't think it really matters 
which GPL-compatible license I use for my admb-mode and .emacs (BSD, GPL, 
LGPL), so I guess I'll go for BSD to align them with ADMB.

Cheers,

Arni