Jean Delvare wrote: > Hi Hans, > > On Tue, 14 Aug 2007 22:52:32 +0200, Hans de Goede wrote: > >> Most people don't realize it but once libraries GPL >> v2 only code depends on become LGPL 3, then the GPL v2 only code can no longer >> be distributed (atleast not as part of a distribution containing LGPL v3 >> versions of the libs the GPL v2 only code depends on). > > I don't get it. You can link even closed-source code with > LGPLv2-licensed code (that was the purpose of this license over GPLv2). > Is this something that changed with LGPLv3? If not, how could you not > be allowed to link GPLv2 code then? > Well, I'm not a lawyer, but both Fedora's (RedHat's) and the FSF lawyers have looked at this. Below is my understanding of the issue as explained to me. The problem is the following section of the GPL: --- The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. --- The problem lies in the "complete source code means all the source code for all modules it contains", which should be translated as "the source for the program + all libraries it uses", This is there to stop people from taking a GPL app putting new interesting stuff in a lib and then ship the app with source with bindings to the lib, but the lib with the new stuff itself under a proprietary license. So the source for all libraries must be shipped, and must be shipped under a GPL version 2 compatible license. LGPL 2 is GPL version 2 and GPL version 3 compatible, so using LGPL 2 libs (or BSD libs) is fine for a GPL version 2 app, but LGPL 3 will only be GPL version 3 compatible not GPL version 2. Thus when a library used by a GPL version 2 only app becomes LGPL 3, that app can no longer be distributed, because we no longer distribute all the needed libraries under a GPL 2 compatible license, as is demanded by the GPL version 2. I hope this clarifies things. Thanks & Regards, Hans
