On May 5, 2009, at 9:23 PM, Brian Granger wrote: > Michael, > > Thank you for bringing up this issue as it does clarify some aspect of > Sage derived code and licensing. But, in my mind, the "sage as > interpreter" aspect is a small perturbation on top of the zero-order: > > Sage = Python + GPL libraries > > That is, for the most part, I view the interpreter as Python itself. > But still the FAQ section is very clear that the presence of all the > GPL libraries loaded into an interpreter is sufficient to make sage > using scripts like Ondrej's GPL bound. I also understand that not > everyone agrees on this interpretation.
The concept of "derivative work" transcends the GPL, what was quoted was the FSF's interpretation of copyright law, which is obviously going to be bias towards maximal viral impact. Personally, I think qualitative aspects are more important than technical aspects (static vs. dynamic linking) in asking whether or not something is morally or legally a derivative work. One could argue with exactly the same logic that a Mathematica worksheet is a derivative work of Mathematica, and a Matlab script is a derivative work of Matlab. (Both are interpreters + large libraries, with much of the underlying core written in the exact same language that the end user uses). The copyrights of these two programs (all rights reserved) don't allow redistribution at all, does that mean every shared Mathematica/Matlab script (without the express permission of the respective coorperations) is a violation of copyright? I think not, and the same applies to Sage worksheets and scripts. The repercussions of this could mean that papers and books couldn't be published with code snippets in them, one would require copyright notices for anyone using Sage in their homework (and showing their work), and we've all been violating the GPL by claiming the wiki is licensed under Creative Commons. (OK, maybe small snippets could be justified under fair use, but still...) > But in my mind, that was the TRIVIAL part of the original question I > asked. The more subtle aspect is centered around this issue: > > * Does "Sharing" a notebook (with other users of the notebook web app) > constitute distribution and is that sufficient to trigger the > application of the GPL? > > In other words, do I need to tell my students... > > "When you share your Sage notebooks with me and other's in the class, > you must agree to license them under the GPL" I think sharing a worksheet, whether it be clicking on the "publish" button or emailing/posting a .sws file all have the same repercussions. In fact, flipping the permissions bit and pointing you to the file under a shared filesystem with the intent that you read it would probably classify as "distribution." Ultimately, in the US system at least, it is the courts that will decide this, but as long as one is clearly respecting the intent of the GPL (which I don't think forces Sage scripts to be GPL'd, though of course that's up to interpretation as well) one retains the respect of the community, and if one is worried about the nitpicky legal aspects, I doubt any Sage developer is going to be suing any of your students for copyright violation for publishing an original notebook :-). > Cheers, > > Brian > > PS[0] = even though I choose to use the GPL myself sometimes, this is > what I hate about it. It is too damn complicated. Even on a strongly > pro-GPL project like Sage, it doesn't seem like most people have any > idea what it says and means. I don't mean to pick on anyone > individually, but on this thread, I have heard _multiple_ different > and incompatible interpretations of the GPL. I wholeheartedly agree. Sometimes I think it's unfortunate that the de-facto standard for copyleft licenses ended up being such a lengthy and messy one. This is one of the beauties of the BSD--it's so clean. Even the CC got this mostly right (it's two pages of legalize, but much better than most). However, if one wants to release code in a copyleft manner, going with the GPL is often a better path than choosing an obscure/incompatible one. > PS[1] = It is even more ironic to me that Ondrej and I are the ones > arguing for the FSF interpretation of the GPL as we are typically > found in the pro-BSD camp. From my perspective, many Sage devs and > users are doing things with Sage derived code that violates the > canonical interpretation of the GPL. If that is just fine, then does > the GPL actually mean anything? (I think it does even though there is > some ambiguity!) I don't think it's odd at all--the more draconian interpretation you have of the GPL the more likely you're to be found in the pro-BSD camp. - Robert --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
