LICENSE

Copyright (c) 2015 Robert Nystrom

------------------------ Commentary ------------------------

The licensing story for this repository is a little complex.
Here's my motivation:

* I want you to get as much use out of the material here as
  possible. I wrote this book to help you, and I don't want
  you to be encumbered when it comes to making the most of
  it. That's also why I put it online for free.

* With my previous book, collaboration on GitHub was
  immesensely helpful. I want to ensure people can fork the
  repo, send me fixes, etc. without violating the license
  or feeling weird.

* When it comes to code, I'm completely comfortable with
  people redistributing, remixing, changing, whatever with
  it. I've been using the MIT license for open source stuff
  for decades.

  This book contains two complete interpreters and I would
  be delighted for them to be the jumping-off point for any
  number of real full-featured language implementations.

* When it comes to my prose and the visual design of the
  site, that feels a little more, I don't know, *me* than
  the code. The words are in my voice, and the look of the
  site is part of its and, by extension, my brand.

  I feel weird thinking about someone, say taking one of the
  chapters and making significant changes to it to fit their
  writing style while still having some of it read like it
  came from me. Likewise, I'd be sad to see another site
  online that looked exactly like mine because it reuses my
  stylesheets.

* My previous book ended up being translated into several
  languages. I want to be careful to not be so permissive
  that it prevents me from signing typical contracts that
  give them exclusive translation rights to certain
  territories and languages.

* If I allow the prose to be redistributed commercially,
  there is nothing preventing someone from slapping
  together a cheap print or ebook version of the book and
  putting it up for sale. I'm not too worried about my own
  sales being undercut, but I very much want to avoid
  readers finding themselves with a low quality book that
  they incorrectly think is from me.

  I worked very hard on this book. I want you to get the
  best possible experience.

All of this is way more complex than I'd like, especially
since my brain isn't wired to care about intellectual
property. I like thinking about making stuff, not thinking
about the legal rights around the stuff I made. (If your
brain is wired to think about legal stuff and you see that
I'm doing something dumb, please do let me know.)

The best solution I've been able to come up with is to use
two licenses:

------------------------ License(s) ------------------------

Each file in this repository falls under one of two
licenses. Files whose extension is ".html", ".scss", ".css",
".markdown", or ".txt" use this Creative Commons license:

    Attribution-NonCommercial-NoDerivatives 4.0
    International (CC BY-NC-ND 4.0)

    https://creativecommons.org/licenses/by-nc-nd/4.0/

All other files, including (but not limited to) ".c", ".h",
".java", and ".py" use the MIT license:

    Permission is hereby granted, free of charge, to any
    person obtaining a copy of this software and associated
    documentation files (the "Software"), to deal in the
    Software without restriction, including without
    limitation the rights to use, copy, modify, merge,
    publish, distribute, sublicense, and/or sell copies of
    the Software, and to permit persons to whom the Software
    is furnished to do so, subject to the following
    conditions:

    The above copyright notice and this permission notice
    shall be included in all copies or substantial portions
    of the Software.

    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
    ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
    TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
    PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
    SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
    CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
    OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
    IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
    DEALINGS IN THE SOFTWARE.