[Paraview] GPL and Paraview and Qt

[Sean Ziegeler]

As they like to say at Groklaw, IANAL (I Am Not A Lawyer), but the GPL 
does allow in-house modification of source code without releasing to the 
public.  This question is explicitly answered on the GPL FAQ, at:
http://www.gnu.org/licenses/gpl-faq.html#GPLRequireSourcePostedPublic

I'll paste it here for convenience:
---------------------------------------------------------
Does the GPL require that source code of modified versions be posted to 
the public?

     The GPL does not require you to release your modified version. You 
are free to make modifications and use them privately, without ever 
releasing them. This applies to organizations (including companies), 
too; an organization can make a modified version and use it internally 
without ever releasing it outside the organization.

     But if you release the modified version to the public in some way, 
the GPL requires you to make the modified source code available to the 
program's users, under the GPL.

     Thus, the GPL gives permission to release the modified program in 
certain ways, and not in other ways; but the decision of whether to 
release it is up to you.

(Copyright (C) 2001, 2006 Free Software Foundation, Inc., 51 Franklin 
St, Fifth Floor, Boston, MA 02110, USA
Verbatim copying and distribution of this entire article is permitted in 
any medium, provided this notice is preserved.)
--------------------------------------------------------

Also, you can and should find the appropriate clause within the GPL 
itself.  I don't recall exactly where, but it is in there.

-Sean

Bonnie Smithson wrote:
> Hello,
> 
>  
> 
> I heard back from Trolltech today about Qt.  I told them that since I 
> was building a commercial, in-house application that I didn’t need to 
> get the commercial version of Qt.  Anne (see below) disagreed with me.  
> She said that in-house, or out of house doesn’t matter.  It is whether 
> or not we would post the source to our changes back to the open source 
> community.
> 
>  
> 
> Can someone please clarify the implications of GPL?  If I extend 
> Paraview to invoke our commercial applications via a custom .dll, I 
> could make Paraview extensions available, but I wouldn’t make the custom 
> .dll available.  Is this complying with GPL?  We wouldn’t be reselling 
> the SW – only using it in-house.
> 
>  
> 
> We will be adding enhancements to itkSnap and Paraview at least, if not 
> vtk and itk.  And we would be able to post those to the open source 
> community as long as we can have some custom .dlls which we don’t share.
> 
>  
> 
> Do I understand this correctly?  If we did want to sell an app that 
> depends on vtk .dlls, other than keeping the copy left in place, am I 
> free to do this?
> 
>  
> 
> - Bonnie
> 
>  
> 
> ------------------------------------------------------------------------
> 
> *From:* Anne Tsirfa [mailto:Anne.Tsirfa at trolltech.com]
> *Sent:* Thursday, February 01, 2007 2:49 PM
> *To:* bonnie.smithson at otismed.com
> *Subject:* Qt licensing
> 
>  
> 
> Hi Bonnie,
> 
>  
> 
> It was nice speaking with you earlier today.  Thank you for taking my call.
> 
>  
> 
>  
> 
> As I was mentioning, Trolltech offers dual licensing model for Qt. 
> Depending on type of application that you’re building, you need either 
> open source license or commercial one.
> 
>  
> 
> You can get detailed licensing info on our web site, here 
> http://www.trolltech.com/products/qt/licenses/licensing/licensingoverview
> 
>  
> 
> To sum up, as a rule of a thumb:
> 
>  
> 
> a)       If you call into Qt’s API – you need a license.
> 
> b)       If you want to use Qt Open Source Edition, you must comply with 
> GPL, which among other things, states that you must contribute all your 
> source code to the open source community.
> 
> c)       If you are building proprietary software – you need to start 
> development with Qt commercial license. You can’t start developing 
> proprietary software using Qt Open Source license.
> 
>  
> 
> It would help if you can provide me with more details about your project 
> and how exactly you’re using Qt and Paraview. Based on what you told me 
> so far,  it sounds like you guys do need Qt commercial license.
> 
>  
> 
>  
> 
> And, finally, our pricing info can be found here 
> http://www.trolltech.com/products/qt/licenses/pricing
> 
>  
> 
> Since you are saying you will only need Qt for GUI part, you need Qt 
> Desktop Light Edition.  1 license with 1 platform support is $1,990.
> 
>  
> 
>  
> 
> Please feel free to contact me if you have any questions, and also let 
> me know how wee proceed.
> 
>  
> 
> P.S. Also, as an FYI – you might want to check with Paraview to see 
> whether you can build proprietary software using Paraview’s application.
> 
>  
> 
>  
> 
>  
> 
> Best regards,
> 
>  
> 
> Anne Tsirfa,
> 
>  
> 
> desk: 650.551.1676 x 135
> 
> cell:  650.793.0501
> 
>  
> 
> **CODE LESS, CREATE MORE!**
> 
>  
> 
> 
> ------------------------------------------------------------------------
> 
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