[Debian-pan-maintainers] Package: Debian PaN: McCode: licencing

[Peter Kjær Willendrup]

Hi all,


Lots of good points, agreed all around:

* We should ensure that normal use of our code generator(s) mcstas and mcxtrace does not imply that the generated code becomes covered by GPL. It should NOT be considered derived work.

* If the above can be met under GPL-3 I also see no issue in swapping. (Which would mean that we can include ncrystal without any issue.) - Pending a relatively likely issue-free ESA ‘OK’ to switch.

* I will talk to the nxs author and find a solution, either:
	- The nxs code and related component forms a “non-free” addition package of sorts
	- Or if he in fact himself considers it deprecated. He gave input to the ncrystal development which by now should be able to do everything nxs does and even supports the *.nxs datafiles.


Best,
Peter


> On 18 Nov 2021, at 17.21, Erik Bergbäck Knudsen <erkn at fysik.dtu.dk> wrote:
> 
> Hi there,
> Thanks for the comments and thoughts. I'd like to mention one thing in relation to this.
> There is an add-on package named AstroX, which is basically is a set of components that have to do with X-ray telescopes. At present this is published under GPLv2, as agreed with ESA. As for the case with nsx - we could simply allow (as it is right now) that package to be a separate add-on, but I would prefer to include it in the normal distro to promote cross-benefits.
> 
> To summarize - if we want to move to GPLv3 - I would have to/like to clear this with ESA. This should not be a problem as they suggested v3 but accepted v2 on my request.
> 
> I hope that made any sense...
> cheers
> Erik
> 
> On 18/11/2021 16:59, FARHI Emmanuel wrote:
>> Hi Roland,
>> thanks for your comments about licencing in McCode. I'm writing through the pan-maintainers mailing list so that we keep track of our thoughts, as well as to theMcCode Danish team leaders.
>> You raise a licencing issue regarding nxs and ncrystal.
>> As a start, The choice of a GPL2 for McCode is mainly historical, but it also related to how McCode works. McCode (McStas + McXtrace) converts a text file into a valid C code, which is then compiled and executed for a beam-line simulation. The generated C file (flex+bison) can be considered as a derived work that some users have used as input for other projetcs. Then, the whole discission boils down into how to consider that generated C code, as part of a derived work, in terms of licence. Is a GPL2 -> GPL3 move viable in this respect ? If yes, then, as discussed today by phone, McCode could move to GPL3, or other suggestion.
>> ncrystal: the lib is Apache 2, which is incompatible with the GPL2 adopted by McCode, but would be with a GPL3.
>> nxs: <https://www.helmholtz-berlin.de/people/boin/nxs_en.html> <https://www.helmholtz-berlin.de/people/boin/nxs_en.html>
>> Its licence is a pure HZB one, which prevents commercial use. It is stated as *not* in the public domain. As a definitive solution, we could exclude libnxs and its only usage elsewhere, mcstas-comps/contrib/Sample_nxs.comp. There are a few data files as well in mcstas-comps/data/*.nxs Then, there is no issue with the static compilation (that could anyway in principle be dynamic).
>> Cheers, Emmanuel.
>> -- 
>> / ___|__/\_| |   | ____|_ _| |      FARHI Emmanuel
>> \___ \\ | |   |  _|  | || |      Div Exp/Data Reduction and Analysis Team
>>  ___) /_  _| |___| |___ | || |___   Tel : +33 (1) 69 35 96 04
>> |____/  \/ |_____|_____|___|_____|  Saint-Aubin BP 48 - 91192 GIF/YVETTE CEDEX
>> SYNCHROTRON  http://www.synchrotron-soleil.fr
> 
> -- 
> Erik Bergbäck Knudsen, Research Engineer         | DTU | morituri
> NEXMAP, DTU Fysik, DK-2800 Kgs. Lyngby, Denmark  |<>-<>|    te
> phone: (+45) 2132 6655                           |<>-<>| salutant