# Qtruby4 license **URL:** \ **Category:** Ruby\ **Created:** [March 3, 2008, 10:20am UTC](https://www.ruby-forum.com/t/qtruby4-license/130781 "2008-03-03T10:20:12Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 10:20am UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/1 "2008-03-03T10:20:12Z")
Hey! I want to use qtruby4 as binding to QT Framework for a commercial ruby application. I do have a QT commercial license. Qtruby4 is GPL. If i use the bindings, does that mean, i have to release the resulting peace of software under the terms of GPL? Are there other options? Thx, CK ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 3:00pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/2 "2008-03-03T15:00:31Z")
On Mar 3, 9:20 am, Christian K. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Hey! > > I want to use qtruby4 as binding to QT Framework for a commercial ruby > application. I do have a QT commercial license. Qtruby4 is GPL. > > If i use the bindings, does that mean, i have to release the resulting > peace of software under the terms of GPL? > > Are there other options? > Well my original plan was to dual license QtRuby, exactly like PyQt is > dual licensed, and offer both a GPL and a paid for commercial version. > But I haven’t got the impression that there would be a critical mass > of commercial users yet to make that worth while. Another problem is that it is difficult to release a Ruby program without source code at the moment, although there have been discussions on this forum in the past about how to do that. The QtRuby code is copyrighted by a small number of people, and it would certainly be possible to add another license type, such as commercial, bsd or mit. If you really do think you need a commercial license please email me to discuss. Note that it wouldn’t be possible to release QtRuby under an LGPL license though. – Richard ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 4:14pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/3 "2008-03-03T16:14:23Z")
On Mon, Mar 03, 2008 at 10:59:54PM +0900, removed\_email\_address@domain.invalid wrote: […] > The QtRuby code is copyrighted by a small number of people, and it > would certainly be possible to add another license type, such as > commercial, bsd or mit. If you really do think you need a commercial > license please email me to discuss. Note that it wouldn’t be possible > to release QtRuby under an LGPL license though. It seems like LGPL would be ideal in this instance. I believe that’s what KDE uses, for exactly the same reasons. Why wouldn’t it be possible for QtRuby? > – Richard > –Greg ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 4:51pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/4 "2008-03-03T16:51:11Z")
And with LGPL it would be possible to have a commerical license for the whole program und just “use” the bindings as library? Gregory S. wrote: > It seems like LGPL would be ideal in this instance. I believe that’s > what > KDE uses, for exactly the same reasons. Why wouldn’t it be possible for > QtRuby? ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 5:12pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/5 "2008-03-03T17:12:47Z")
On Mar 3, 3:10 pm, Gregory S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > It seems like LGPL would be ideal in this instance. I believe that’s what > KDE uses, for exactly the same reasons. Why wouldn’t it be possible for > QtRuby? > Because I would need permission from Trolltech and my understanding is > that they don’t like an LGPL license used with language bindings, > although they are happy that the KDE libs are LGPL’d. A few years ago, when I asked them about changing the QtJava license from GPL to LGPL, they were very much against the idea. They were much happier with a QtJava dual license GPL/commercial to match the licensing scheme of Qt itself. The QtJava bindings were never as successful as the QtRuby ones have been, and I really don’t think there would have been much demand for a commercial version from a one man company such as mine. The QtJambi Java bindings are more successful some years later, perhaps because they have Trolltech’s marketing expertise and development funding right behind them. QtJambi is dual licensed of course. Their view may have changed now, and I haven’t discussed it with anyone from Trolltech for a while. Now that Qt is getting better and better, and Ruby is beginning to really get some great runtimes, I think it makes sense to start thinking of some sort of commercial QtRuby version. – Richard ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 5:13pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/6 "2008-03-03T17:13:58Z")
On Tue, Mar 04, 2008 at 12:51:06AM +0900, Christian K. wrote: > Gregory S. wrote: > > > It seems like LGPL would be ideal in this instance. I believe that’s > > what KDE uses, for exactly the same reasons. Why wouldn’t it be > > possible for QtRuby? > > And with LGPL it would be possible to have a commerical license for the > whole program und just “use” the bindings as library? Almost correct. The LGPL is compatible with the GPL, so a fully GPL’d program can use it and, through it, a GPL-licensed Qt library. The LGPL only applies to the specific code (usually a library) licensed with it, however, so a commercial product could use a commercially licensed Qt library through the LGPL’d QtRuby library and distribution of the application would only involve an obligation to provide the QtRuby source (under the LGPL), not the Qt source nor the source of the program nor any license to that source. IANAL, but this sort of compromise has come up in the past, for exactly these reasons, and KDE is the prime (and most relevant) example. –Greg P.S. please don’t top post. ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 5:25pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/7 "2008-03-03T17:25:44Z")
On Tue, Mar 04, 2008 at 01:10:00AM +0900, removed\_email\_address@domain.invalid wrote: > > > to release QtRuby under an LGPL license though. > > > > It seems like LGPL would be ideal in this instance. I believe that’s > > what KDE uses, for exactly the same reasons. Why wouldn’t it be > > possible for QtRuby? > > Because I would need permission from Trolltech and my understanding is > that they don’t like an LGPL license used with language bindings, > although they are happy that the KDE libs are LGPL’d. I am confused. Why would you need Trolltech’s permission for this? Developing an LGPL library against a GPL library is one of the (implicit) freedoms granted by the GPL. In fact, unless you and other contributors had a Qt developer license the entire time you and they were developing QtRuby, I don’t believe you would be able to provide QtRuby under any license that was not GPL-compatible. Basically, if you didn’t have the right (by having purchased a developer license from Qt) to develop closed code while you were doing it, you don’t have the right to close the code. > A few years ago, when I asked them about changing the QtJava license > from GPL to LGPL, they were very much against the idea. They were much > happier with a QtJava dual license GPL/commercial to match the > licensing scheme of Qt itself. > […] I find that bizarre, but I’m still not clear on why they have any say in the matter. > Their view may have changed now, and I haven’t discussed it with > anyone from Trolltech for a while. Now that Qt is getting better and > better, and Ruby is beginning to really get some great runtimes, I > think it makes sense to start thinking of some sort of commercial > QtRuby version. I still say their view is irrelevant. Legally, I don’t believe you can release QtRuby under any license that isn’t GPL-compatible at this point. IANAL, but that’s what my reading of Qt’s commercial license seems to imply. > – Richard > –Greg ---
**Author:** ![sealedsun](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/e68b1a/32.png) [@sealedsun](https://www.ruby-forum.com/u/sealedsun)\ **Post date:** [March 3, 2008, 6:20pm UTC](https://www.ruby-forum.com/t/qtruby4-license/130781/8 "2008-03-03T18:20:55Z")
On Mar 3, 4:24 pm, Gregory S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > > > license please email me to discuss. Note that it wouldn’t be possible > > > > I am confused. Why would you need Trolltech’s permission for this? > > > > happier with a QtJava dual license GPL/commercial to match the > > > > think it makes sense to start thinking of some sort of commercial > > > > QtRuby version. > > I still say their view is irrelevant. Legally, I don’t believe you can > release QtRuby under any license that isn’t GPL-compatible at this point. > IANAL, but that’s what my reading of Qt’s commercial license seems to > imply. > Well I’m relaying to you what Trolltech’s view was last time I spoke > to them about licensing. There is no way I would ignore their views on > something like this, and it is quite wrong to describe their view as > ‘irrelevant’. Free Software developers are partners of Trolltech, in > the same way that commercial licensees are, although they have > different rights and obligations - we’re all part of the same eco- > system. – Richard