Re: GPL and closed source
On Thu, Jul 12, 2001 at 07:39:21AM -0700, Greg Herlein wrote: Let's say that I've developped a programm under GPL. Is it possible to create Closed-source plugins for the GPL programm and sell them ? If you own the copyright to the larger framework, this can be done legally. You'll want to make sure that you either completely own, or have disclaimers or assignment of rights documents from all developers. If the framework is yours, you can take all or part of it closed source at will - you own it. However, if the framework is not clearly under your copyright, then you can't do this, since you cannot link closed source to an open source framework - and pluggable modules are considered to be linking. Selling closed source plugins wouldn't be illegal anyway, but wouldn't it be illegal for the buyers to link the bought plugins with the GPL-ed opensource? If so then that means that together with selling a plugin you'd have to give a version of the open source program under a different license, and that means that the buyers are not allowed to link their plugins with a later distributed, modified, GPL-ed version. Therefore, the only way seems to be to use a GPL license with an exception from the start (which also can only be done if you are the copyright holder) that says that these plugins will be excluded from the GPL. I am not sure if such an exception wouldn't cripple the GPL in the sense that you'd need signed disclaimers or assignment of rights documents from all developers despite that they send you patches for the work that already included the exception. I am interested in this myself, so if anyone can enlighten me: lets take the following similar example: http://www.gnu.org/philosophy/license-list.html section The Qt Public License (QPL). says: If you want to release your program under the GNU GPL, you can easily do that. You can resolve the legal conflict for your program by adding a notice like this to it: As a special exception, you have permission to link this program with the FOO library and distribute executables, as long as you follow the requirements of the GNU GPL in regard to all of the software in the executable aside from FOO. Now suppose someone modifies this work and redistributes it. Is it then such that this exact license still holds, automatically? Including this exception thus? I ask this because I thought that the GPL worked solely because it GIVES right, and not takes them. But after adding this exception you'd need signatures from other authors, perhaps. -- Carlo Wood [EMAIL PROTECTED]
Re: GPL and closed source
While I'm even less of a lawyer than most folks here, I disagree. My opinion is that you *can* write a closed source plugin to work with a published interface, and distribute it for a fee, and nobody can stop you from doing that. I also remember having read here that RMS is of the opinion that if the interface only has been implemented in a GPL-program, then my stance is wrong, and you cannot distribute your closed source plugin. So let us consider: It is pretty clear from the text of the GPL that you cannot distribute your closed source plugin *linked into* the GPL-program. But if you distribute the GPL-program and the plugin separately, I don't see any problem with users throwing the two together. I don't think such users would contravene the GPL, since they're doing no developing or distributing of code, just using several programs as they see fit on their own computers. The argument that shows why RMS' opinion on this matter (assuming he was quoted correctly) is wrong and you *can* do this is that you could at any time develop a closed source program that implements the published interface to which your plugin links. If the FSF were to sue you, you'd have to take the stance that you are distributing the plugin first, before writing the closed source replacement/improvement of the core GPL-program. So IMO, the fact that you *could* implement the interface yourself in a closed source program makes it impossible to fault you for selling a closed source plugin to that future program. Problems might arise if the interface itself were proprietary. If yours is a serious commercial venture, you should talk to a lawyer about that possibility. Again, IANAL, I'm just going by my understanding of the GPL and what I consider just and fair. As a final thought, I think the FSF would be crazy to test the GPL in court on this issue, where the claim they're making is much weaker than in other cases of potential license violation (like all the GPL code that was linked to Qt before that was GPL). Peter Henningsen alifegames.com At 07:39 AM 7/12/01 -0700, you wrote: Let's say that I've developped a programm under GPL. Is it possible to create Closed-source plugins for the GPL programm and sell them ? If you own the copyright to the larger framework, this can be done legally. You'll want to make sure that you either completely own, or have disclaimers or assignment of rights documents from all developers. If the framework is yours, you can take all or part of it closed source at will - you own it. However, if the framework is not clearly under your copyright, then you can't do this, since you cannot link closed source to an open source framework - and pluggable modules are considered to be linking. This is my non-legal opinion, of course. Greg
RE: GPL and closed source
From: Carlo Wood [SMTP:[EMAIL PROTECTED]] Selling closed source plugins wouldn't be illegal anyway, but wouldn't it be illegal for the buyers to link the bought plugins with the GPL-ed opensource? If so then that means that My impression was that the FSF only really cared about re-distribution, so the real issue would be with the fact that the proprietory plug-in might have to be linked against a copy of the shared library by the supplier, a borderline case, needing a real lawyer. My impression is the whole area is sufficiently borderline to require a real lawyer. There are precedents for GPLed containers running proprietory code, e.g. the Linux HP Desk Jet drivers (this might be LGPL). The proprietory part is not linked - I think the communication is either through pipes or through sockets. -- --- DISCLAIMER - Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of BTS.
