[Ctk-developers] CTK range slider

[Marco Nolden]

I think it's fine to re-use and include non-GPL code in GPL projects, as 
long as you clearly declare an exception for the included code 
(otherwise our Apache license wouldn't be permissive).

On the GPL page you can find an example text you should add in your 
license/program:

http://www.gnu.org/licenses/gpl-faq.en.html#GPLIncompatibleLibs

I won't comment on which license is more following the "open source" 
philosophy ;)

Best,

Marco

On 10/07/2013 03:00 PM, Julien Finet wrote:
> Hi Massimo,
>
> I gave a look at QLC+ and it seems to be a cool project, nice job !
>
> Thanks for your interest in CTK.
> Let me first begin by saying that I am not a license expert but I cc-ed
> the CTK community and our license experts at Kitware.
>
> Having said, here are my thoughts:
>    - The CTK community has chosen the Apache 2 license to give access of
> CTK to most people with less restrictions as possible (in the true
> open-source kind of way :-) ).
>    - Therefore, if you don't hear otherwise, we would be happy to grant
> QLC+ access of CTK if you keep the license header in the CTK files you
> embed in your project.
>    - I would strongly suggest that you change your license to a more
> recent version of GPL (v3?), or even better, to a more permissive
> license (such as Apache 2) to fully embrace the "open source"
> philosophy. Indeed, the licensing issue of CTK within QLC+ does not
> (seem to) come from Apache 2, but from the very restrictive GPLv2 (that
> is not even compatible with GPLv3 code). In the long run, it would be
> very counter productive for you guys to refrain yourself from re-using
> all the open source libraries available and you would waste lots of time
> trying to reinvent the wheel each time.
>    - Finally, we would surely appreciate (but it is not mandatory) that
> you publicly mention CTK in your project. For example, on your website
> (an acknowledgment page maybe ?) or/and in your software (in an "About"
> dialog).
>    - Feel free to contribute patch (using the github pull request
> mechanism) if you found and fixed bugs or added features.
>
> Best regards,
> Julien.
>
>
> On Mon, Oct 7, 2013 at 4:31 AM, Massimo Callegari
> <massimocallegari at yahoo.it <mailto:massimocallegari at yahoo.it>> wrote:
>
>     Hello Julien,
>     I found your email address on Github.
>     First of all, I just want to say you're doing a great job with the
>     CTK project !
>
>     I am the maintainer of another open source project called QLC+:
>     http://qlcplus.sourceforge.net/index.shtml
>     It's released under the GPLv2 license.
>
>     Yesterday I was looking around for a solution about a range slider
>     in Qt and I found yours.
>     So I've got 2 questions:
>     - I would like to ask the permission to the CTK team to use the
>     ctkRangeSlider class in my project
>     - since you release CTK with the Apache 2.0 license, according to
>     this page
>     http://www.apache.org/licenses/GPL-compatibility.html
>     it seems it is not compatible with GPLv2, so I'm wondering if you
>     ever face issues like this.
>     In case, would it be possible to grant to the QLC+ project a
>     "special" release of the range slider class under GPLv2 ?
>
>     Thank you very much in advance !
>
>     Regards,
>     Massimo
>
>


-- 
----------------------------------------------------------------------
Dipl.-Inform. Med. Marco Nolden
Deutsches Krebsforschungszentrum       (German Cancer Research Center)
Div. Medical & Biological Informatics          Tel: (+49) 6221-42 2325
Im Neuenheimer Feld 280                        Fax: (+49) 6221-42 2345
D-69120 Heidelberg                             eMail: M.Nolden at dkfz.de