Subj : Re: Copyright and addons or comercial GUI for a GPL software To : comp.programming From : Peter Ammon Date : Thu Aug 11 2005 11:06 am Rob Thorpe wrote: > aslanski2002@yahoo.com wrote: > >>Giannis Papadopoulos yazdi: >> >>>aslanski2002@yahoo.com wrote: >>> >>>>Jonathan Bartlett yazdi: >>>> >>>> >>>>>>Are there any restrictions in using GPL code in comercial applicatins? >>>>> >>>>>Yes. >>>>> >>>>> >>>>> >>>>>>I have seen the Linux Kernel used on a lot of appliances. >>>>> >>>>>That's because the kernel is not linked to the program. >>>>> >>>>> >>>>> >>>>>>My intention as I mentioned in an earlier thread is to design a good >>>>>>interface for some GPL applications and to sell this interface. >>>>> >>>>>Selling is not against the GPL. Selling under non-GPL licenses is. >>>>> >>>>> >>>>> >>>>>>I will >>>>>>not charge for the application itself but I think it is fair to charge >>>>>>for the interface. The design requires a lot of work for design and >>>>>>implementation. >>>>> >>>>>The amount of work is irrelevant. What is relevant is whether or not >>>>>your work is considered a derivative work. >>>>> >>>>>If you link to libraries, that is usually considered a derivative work. >>>>> Static linking definitely is, dynamic linking using headers supplied >>>>>under the GPL also is. I do not know of the rules for dynamic linking >>>>>without the GPL headers. However, if you are not linking to the GPL >>>>>work, but merely using it as a separate application, there is no >>>>>problem. In fact, I know Mathematica does this. If you look on the CD >>>>>they distribute you will see a source file containing a GPL application >>>>>which they use as a separate, unlinked application but is distributed >>>>>with Mathematica. >>>>> >>>>>As for LGPL libraries, there are other rules. With those, you are >>>>>allowed to freely dynamically link. For static linking, there are more >>>>>rules, but basically you have to provide the unlinked versions of both >>>>>your code and the libraries, so the user can upgrade the library and >>>>>relink if he wishes. >>>>> >>>> >>>>I have questions here: >>>>I have an application *A* which uses a DLL *D1* with (L)GPL code in it >>>>and another *D2* which has no (L)GPL code. *A* still can work if you >>>>delete *D1* (though not fully functional). And *A* has no (L)GPL code >>>>in it. >>>>- Do I still have to provide sources for *A* ? >>>>- I don't think I have to provide the sources of *D2*, do I? >>>> >>>> >>>> >>>>>Jon >>>>>---- >>>>>Learn to program using Linux assembly language >>>>>http://www.cafeshops.com/bartlettpublish.8640017 >>>> >>>> >>>If D1 is GPL, then yes you have to provide A sourcecode. If it is LGPL >>>you don't have. >>> >> >>What if I provide *A* and *D1* as proprietary and some knowledge of how >>to create a plug-in for *A*. And some user creates a plug-in for *A* ( >>call it *D2*) using some GPL code, isn't this the case where I have to >>provide source of *A*? I can't stop a user doing it! > > > No, the user can't create a plugin with a GPL license and link it to a > proprietry application. If the user want to apply the GPL to any part > of the whole he/she must provide source code for the whole, which they > can't do without the proprietry source code. > > Read the GPL FAQ http://www.gnu.org/licenses/gpl-faq.html > > I of course would prefer it if you just GPLed the whole thing; much > simpler and better for the users. If the GPL prevents people from distributing certain plugins, that they would be able to distribute were the code in question not GPLed, then that's worse, not better. I'm in a similar situation. I wrote a program that links against a GPLed library. This is preventing me from distributing an important plugin, which uses code that has an open source license incompatible with the GPL. -Peter -- Pull out a splinter to reply. .