Rick, I've tried to reply at length below on the issue of license (in)compatibility. The below is probably the most I've ever written on the subject, but it's in some ways a summary of items that discussed regularly among various Free Software licensing theorist for the past decade, particularly Richard Fontana.
Rick wrote yesterday: > It's a fair, interesting, and relevant question, and I'd really like to > know the answer. Most things in policy, unlike science, aren't a technical problem where we can provide a hypothesis and test the results. So, there probably isn't "an answer". I've observed that many lawyers often build their careers on *pretending* that there are answers to questions like this. Then, they simply bluster their way through to convince everyone. Since IANAL (and, BTW, TINLA), I don't tend to think that way. I won't pretend license compatibility is a testable scientific fact like Einstein's theory of relativity; it's a policy analysis and conclusion, based on what those doing the analysis think is correct and likely to be permissible under copyright. > I'd actually be interested in Bradley ... pointing to any caselaw that > supports [his] view. So, most importantly, I don't think there has been any litigation anywhere in the world regarding "license compatibility". Specifically, Jacobsen v. Katzer didn't consider it AFAICT. And, (speaking as someone who has either advised the Plaintiff and/or actually been the 30(b)(6) witness for Plaintiff in all of the GPL enforcement lawsuits in the USA), I'm not aware of the license compatibility ever coming up in USA litigation. Also, note that, no one else in this thread has put any "license compatibility" caselaw forward; it just doesn't exist, AFAIK. However, even if there were caselaw, I don't think looking at the caselaw record is somehow the only way to consider these questions. My primary point throughout this thread is that Free Software projects are regularly concerned about compatibility (and license proliferation too), for good policy and "project health" reasons; not because of what some Court said. I'd suspect everyone to agree that you must meet the redistribution requirements of all copyright licenses for a given work to have permission to redistribute. Thus, license compatibility *exists* as a concept because if you make a new work that combines two existing works under different licenses, you have to make sure you've complied with the terms of both licenses. Again, I'd be surprised if anyone disputes that as a necessary task and requirement. Where people disagree is about whether or not you actually need copyright permission at all to create that new work. Some have a theory that it's virtually impossible to ever need such permission. I'm pretty sure that can't be right, and there is a lot of caselaw on *this* subject, but the tests that courts have come up are *highly* dependent on the facts of a specific set of circumstances for a specific work. (Dan Ravicher's article the "Software Derivative Work: A Circuit Dependent Determination" is a seminal source on that subject about the USA situation. Till Jaeger's talk at FOSDEM, a recording of which I already linked to in this thread, covered the European side quite well IMO.) Of course, derivative works analysis has almost *nothing* to do with license compatibility. It's just that folks love to fall into derivative works debates because it's an interesting topic, and because those whose primary goal is to circumvent copyleft as much as possible (and I've found that's most people who work as "Open Source" legal experts) prefer to point to the "derivative works issue" as some sort of insurmountable problem that is therefore the "base case" of every discussion about Free Software licensing. And, as you saw, this thread descended into that debate too. I suspect that's what led Luis Villa to have his "oh no, not again" reaction. Meanwhile, "license compatibility", as a concept, is a lex mercatoria. (Fontana and others have talked at length about how much in Free Software licensing are leges mercatorum; ironically, the derivative work question may be the only central issue that *isn't* a lex mercatoria.) Specifically, no court anywhere in the world, to my knowledge, has sat down and lined two Free Software licenses up next to each other and tried to determine if, upon creating a whole work based on two works under the two licenses, if the terms of any license was violated and thus the distributor of that whole work infringed copyright of one party or the other. Thus, people argue about what a court might say. Some lawyers bluster and claim they know the answer when they really don't. (This is why I love Till's first FOSDEM slide: he admits, as a first principle, the Socratic Epiphany inherent in this type of work.) In the meantime, though, we have to operate, share code, and (hopefully) uphold software freedom -- with the tools we have. That's what led me, back when I started working for the FSF in 2000 [0], to publish on the FSF's site a list of licenses that rated them on two primary criteria: (a) whether the license respects the four freedoms or not, and (b) which are compatible with the GPL and which aren't. That page has been improved regularly for 13 years: http://www.gnu.org/licenses/license-list.html Of course, some people disagree with the FSF's conclusions. I tend to think the license drafter's opinions on such subjects, particularly in a lex mercatoria situation, deserve much more weight than random opinions from folks with an axe to grind. For example, if the Eclipse Foundation publishes compatibility guidance about the Eclipse License, I'm going to trust their opinion more than my own, as should you. Similarly, I recommend that people trust that the FSF knows what its own license says and how it's intended to work. I think ignoring the license drafters view is a recipe for substantial risk and potential copyright infringement. (The first person to trust, BTW, even before the license drafter, is the copyright holder(s)! And, I note that most people who tend to opine on this subject *aren't*, nor do they represent, copyright holders in any copylefted Free Software works, and many don't even *use* copylefted software all that regularly. Interesting, that, huh?) Fontana and I, have, FWIW, spent an inordinate amount of time analyzing and considering all possible license compatibility theories. (There are roughly 2-3 we've found that pass any sort of logical merit.) It's basically a standing agenda item that he and I talk about every time we meet. I don't know how much thinking everyone else in Free Software has done on this topic, but I'd suspect Fontana and I have spent more time on this question than anyone else. It's on the order of hundreds -- possibly more than a thousand -- hours over the last six years. I take Rick Moen's hint that it'd be good if we wrote more about the subject, but that's a tough thing to fund: we don't have the huge resources of wealthy (often GPL-violator-defending) law firms and academic institutions, which is where most writing on these topics comes from. Rick Moen wrote further: > And, like Larry, I'm not seeing any overwhelming flood of mailing list > traffic. I don't mind extra traffic either, as we can all easily delete threads that aren't useful. My main concern was that the subthread might be truly off-topic, but only Luis has indicated that it might be and others have said they feel it's on-topic, so I'll go with majority there. Thus, my only remaining objection to this thread is being told personally that a large part of my life's work is "a fear-mongering infection upon our community", but I'll just ignore the people on the thread who are claiming that from now on. :) It certainly isn't the first time (or, even this first time *this* year), that someone has resorted to name-calling against those of us who enforce the GPL. At least Larry didn't compare me to Joe McCarthy like Mark Shuttleworth did regarding the topic of GPL enforcement. :) [0] http://web.archive.org/web/20000815065020/http://www.gnu.org/philosophy/license-list.html -- -- bkuhn _______________________________________________ License-discuss mailing list License-discuss@opensource.org http://projects.opensource.org/cgi-bin/mailman/listinfo/license-discuss