[Ctk-developers] COPYRIGHT & LICENSING

[Steve Pieper]

Agreed - I'm reluctant to use LGPL'd code for these reasons.  However it 
may be required in practice by our choice of Qt and the trends for 
meaningful participation in that development community....

-Steve

On Apr/14/10 9:51 AM, Luis Ibanez wrote:
>
> Just a word of warning:
>
> Should CTK include any code that is distributed under the LGPL license,
> it will be very important for such code to be clearly labeled and to be
> build
> only as an option.  Ideally it should be put in a separate directory, or
> even
> better, in a separate source tree.
>
> That is,
> none of the essential classes should be covered by a LGPL license.
>
>
> The eventual LGPL code should then be compiled and archived into a
> *shared* library, in order to avoid propagation of the license to the rest
> of the system.
>
>
> The option of using LGPL code should probably be turned one from the
> CMake configuration at build time, and should be accompanied by the
> proper warnings, to make developers aware of the consequences that
> activating this code will have for the Licensing of the application that
> they are building at that point.
>
>
>         Luis
>
>
> -------------------------------------------------------------------------------------------------------------
> On Wed, Apr 14, 2010 at 8:52 AM, Steve Pieper <pieper at bwh.harvard.edu
> <mailto:pieper at bwh.harvard.edu>> wrote:
>
>     Additional considerations regarding Qt:
>
>     Qt samples and user-contributed widgets are typically licensed under
>     the LGPL or the GPL (depending on history and developer preference -
>     see http://qt-apps.org for examples).
>
>     My understanding of the Nokia policy is that if we start with /just/
>     the LGPL'd Qt distribution and write a widget, we can distribute our
>     widgets under any license.
>
>     However if we *incorporate and modify* existing GPL or LGPL code we
>     need to use the same license for our resulting code (the 'copyleft'
>     requirement).
>
>     Note that it is probably okay to /use/ an LGPL'd widget set via
>     superbuild without impacting the licensing of CTK widgets themselves
>     (for example, if we wanted to subclass existing widgets from
>     something like Qxt http://www.libqxt.org/).
>
>
>     As a practical matter, at the intersection of development and
>     governance, we need to develop a policy about what external code we
>     can incorporate in CTK and we need to be careful to follow that policy.
>
>     My recommendations based on the current environment are:
>
>     1) Qt-based CTK Widgets will need to incorporate LGPL'd example code
>     from the wider developer community and will therefor need to be
>     under the LGPL license (different from the rest of CTK).
>
>     2) CTK developers will carefully review any projects from which they
>     wish to draw code and strictly avoid using any GPL'd code.  (If the
>     code is particularly unique and valuable, contact the authors and
>     ask if they will consider releasing an LGPL or BSD-style version).
>
>
>     I would be very interested in comments from experienced Qt
>     developers on these topics:
>
>     - does the analysis above match your understanding?
>
>     - do we need to base our CTK widgets on LGPL'd examples?  Or could
>     we accomplish our goals while adhering to a strict Apache/BSD-style
>     licensing approach only?
>
>
>     Regards,
>     Steve
>
>
>
>