On Fri, Dec 13, 2013 at 1:56 AM, Mingjie Xing <[email protected]> wrote: > Hello, > > I think maybe this is a good place to ask a question about GFDL. Say I > am going to write a book talking about the implementation of a GPLed > software. Many source code will be quoted and analyzed in the book. So > my question, is there any constraint about the publishing book? Must > the book be covered as GFDL? Thanks.
First, let's talk licenses. GFDL and GPL are two separate licenses created and published by the Free Software Foundation. Although both leverage copyleft principles, there's no requirement in either license to use the other.[0] --- Now let's talk about copyright. Laws vary from country to country, but generally speaking one may quote short passages of copyrighted works for purposes of commentary. To quote the US Copyright Office[1], some examples that courts have found to be Fair Use include: "quotation of excerpts in a review or criticism for purposes of illustration or comment; quotation of short passages in a scholarly or technical work, for illustration or clarification of the author’s observations;...reproduction by a teacher or student of a small part of a work to illustrate a lesson" So if your inclusions of code are short, relative to the rest of the work, and/or if you are directly critiquing the software, then the inclusion of the copyrighted content may qualify as Fair Use. In your case it doesn't sound like you're talking about multiple FOSS projects spanning multiple codebases, but just about a single project. If you're using a substantial amount of source code in the book, one option would be to adopt the GPL license of the code itself. This is perhaps the easiest option, as you then may modify/write/quote/etc.. as much or as little of the codebase as you like, and feel quite confidently protected by the terms of the GPL. Another great option is to first talk with the authors of the software about your project, and then send them your proposal. Getting written permission from them to write about (and include sections of) the software under a particular license (e.g. GFDLv1.3 or CC-BY-SA 4.0) will not only put you on a stronger legal foundation, it will hopefully give you better access to members of the project if you have any questions about the codebase while writing your book. Good luck! --R, IANAL but I know too many of them... :-) [0] The GFDL describes the GPL as being "complimentary" and suggests that one might dual-license (under the GPL) any significant code chunks in a GFDL-licensed document. [1] http://www.copyright.gov/fls/fl102.html
