First, IANAL. In non-hypotheticals, you should talk to one as well as the relevant open source project leadership committees. Also the GPL v2 and the GPL v3 may be slightly different here because the GPL v3 moves away from being reliant on derivative works definitions in some important ways. In general, good will from the projects at issue is a factor that should not be underestimated and being a good citizen means ideally making sure they are ok with it.
I can tell you how the LedgerSMB core team approaches this. We draw a hard line between "using our code" (requires adhering to the GPL) and using our API (does not). In practice this means if you use our code as a basis for your code whether through object inheritance, literal copying, or paraphrasing, we expect you to adhere to the GPL v2. If OTOH you simply invoke the Perl modules and use the API we have provided (or call the stored procedures, etc), no such requirement exists. Note that this makes the GPL v2 in our view somewhere between what RMS would like it to be and what he thinks the LGPL gets you (but closer to his view of the LGPL). This is not so different as I understand it from Linus's view of the GPL. This is intended on our part to keep the "based on" language in the GPL v2 to be close to the derivative works definition in copyright law and recognizing that nobody needs copyright licenses from Microsoft to write, say, Internet Explorer plugins. In this view, there is no problem. There wouldn't even be a problem, in this view, if the libraries were linked provided that the code connections are not so intimate as to create a derivative work (for example, I would argue that class inheritance in fact does this). If this were LedgerSMB and the GPL v2, the answer would be to your lettered questions: a) It depends. I would be inclined to say stay away from this one. b) Probably safe c) No less safe than b under any license d) Safe. e) Safe f) Safe As for the GPL v3, I am guessing that "a" is not safe, b and c might or might not be depending on the project, jurisdiction issues, and distribution format. d-f would strike me as safe, but again might depend on implementation. Also note that the above (d-f) might not be safe with the proprietary app license but that's beside this hypothetical, right? However in the end asking projects is the best way forward. If a project is going to have a more Stallman-like view of the GPL, probably better to avoid even being threatened unless you really want to fight (and then talk carefully with your lawyer first). If the project has a more Linus-like view, then things are easier. Best Wishes, Chris Travers _______________________________________________ License-discuss mailing list [email protected] http://projects.opensource.org/cgi-bin/mailman/listinfo/license-discuss
