On May 5, 2009, at 11:12 PM, William Stein wrote:
> > On Tue, May 5, 2009 at 10:41 PM, Robert Bradshaw > <rober...@math.washington.edu> wrote: >> >> 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. > > Note that the GPL is "viral", but the MATLAB/Mathematica/etc > copyrights are not. The MATLAB/Mathematica/etc copyrights don't allow any redistribution, so if their worksheets are derivative works, then one isn't allowed to share them at all. (On the other hand, if they're not derivative works, then nor is a Sage worksheet, and so it's not required to be GPL'd). >>> "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." > > The GPLdistinguishes between sharing privately (in an organization) > and publishing publicly. See the GPL FAQ: Also, does that also mean no Sage code could be included in a paper in a journal that required signing the copyright away? What about publishing (collections of) worksheets under the CC license? Code snippets in books? Are your books GPL compatible? (Maybe you could claim fair use.) I have no trouble licensing code under the GPL, but I do think this places an onerous and inappropriate burden on all *users* of Sage, and the GPL is supposed to be about modifying/distributing code. - 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 -~----------~----~----~----~------~----~------~--~---
