On Tue, Dec 29, 2009 at 7:35 PM, Jason Grout <jason-s...@creativetrax.com> wrote: > I'm posting this to (1) share what I've learned by reading a lot over > the last little while, and (2) ask for advice from people that have > thought a lot about licensing of books and notes. > > I'm looking at different licenses for a Sage-enhanced set of notes, in > the spirit of the CCLI grant proposal that was posted here a few days > ago (please go read it and make comments! [1] :). I see these notes as > incorporating Sage code in examples, like you see in William's number > theory book or other tutorials that we've seen in various places. > > I've spent a while reading up on licenses, and it seems that there are > three good possibilities for an "open" license that would allow others > to make modifications and freely redistribute the result: > > 1. GNU Free Documentation License 1.3 > 2. Creative Commons, Attribution-ShareAlike 3.0 > 3. plain old GPL > > GFDL and CC-by-sa are not compatible with GPL, so if I wanted the notes > to be distributed with Sage (so the examples turn into doctests, etc.), > if I went with (1) or (2), I'd have to dual-license the notes with GPL.
I think we have a firm commitment to only include in Sage software whose license is GPLv2+ compatible. It is not necessary that we make the same commitment for books/articles/documentation/etc. included in Sage. For example, last time we had nearly the same discussion at length (maybe 2 years ago on sage-devel?) mainly about the wiki, we together concluded that content posted on the wiki be licensed as follows: "By making an explicit contribution to the Sage wiki (or the Sage documentation), one certifies that one's contribution is licensed under the Creative Commons 3.0 license." See http://wiki.sagemath.org. > However, several organizations have just adopted plain GPL for their > documents ([2], maybe Debian too?). GNU does not encourage licensing > documents with GPL [3], though. > > The major difference I see between GFDL and CC-by-sa is that CC-by-sa > does not have the requirement that the source be distributed with the > work. The statement you just made above about GFDL is false. The relevant statement in the GFDL is: "If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material." It is important to read the definitions in order to understand the previous sentence -- see http://www.gnu.org/copyleft/fdl.html > I like that (I really wish there was a CC-by-sa-src, with that > added requirement). That is not a requirement of GFDL. > However, it seems that there are lots of problems > with the GFDL license, not the least of which is the incompatibility > with GPL. See [4] or [5]). > > So what do others do that have written notes that hopefully will > eventually be distributed with Sage think? > > Thanks, > > Jason > > > [1] > http://groups.google.com/group/sage-devel/browse_thread/thread/3e9f66cf3fc3405f# > > [2] http://en.flossmanuals.net/bin/view/Blog/LicenseChange > > [3] http://www.gnu.org/licenses/gpl-faq.html#WhyNotGPLForManuals > > [4] > http://web.archive.org/web/20031009105046/http://home.twcny.rr.com/nerode/neroden/fdl.html > > [5] http://en.wikipedia.org/wiki/GNU_Free_Documentation_License#Criticism > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
