CC Share-Alike for Open Source Software
<p>I've been developing a mobile app to help players and GM in a RPG titled Anima Prime. The game itself is licensed in Creative Commons Attribution-Share Alike 3.0.</p>

<p>I'm no native speaker of English so I don't really grasp what the license really means. Therefore, I used <a href="https://www.quora.com/What-in-laymans-terms-are-the-different-licenses-that-fall-under-Creative-Commons" rel="nofollow">this</a> as the guideline.</p>

<p>Quoting from the site:</p>

<blockquote>
  <p>Attribution - Share-Alike (CC BY-SA) - This allows you to use the CC-licensed work in nearly any way so long as you say where and who you got it from, and the new work is also issued under a BY-SA license.</p>
</blockquote>

<p>So it means I must mention the site from which I download the rulebook and who the author is and the app I've been developing must be licensed in the <strong>same exact license</strong> as the rulebook, doesn't it?</p>

<p>But <a href="https://wiki.creativecommons.org/wiki/Frequently_Asked_Questions#Can_I_apply_a_Creative_Commons_license_to_software.3F" rel="nofollow">this wiki</a> said that CC licenses are discouraged for software. So what license I should use for my app? I intend it to be an open-source software.</p>

<p>If I got you correctly, the game and the rulebook are licensed under a Creative Commons licence. Creative Commons licences are usually used to license content (texts, images, etc.) and not software code, as you already mentioned. So, assuming you are using texts from the rulebook, those texts are covered by CC-BY-SA. Thus, if you merely copy the texts into your app to display them to other users of the game, you need to place the texts (not your source code) under CC-BY-SA (as some kind of copyright notice in your app, for example).</p>

<p>Note that this only affects "using" the covered works (texts / images etc. from the rulebook). Developing an app to <strong>display</strong> that content should not in itself touch on the licence of the rulebook. It is IMO instead the creation of an entirely <strong>different</strong> work, for which you could choose any licence you might like (of course, if you include other Open Source software in your source code, you might need to adhere to those licences, but this was not in question here). One could regard the app as a vessel for information, like an MP3-player or a TV, which are usually independent from the content they display. </p>

<p>May I recommend the Mozilla Public License?</p>

<p>For source code, any modified <em>files</em> must also be subject to the copyleft clause of the license. These derivatives must be released under the Mozilla Public license as well. However, new files aren't subject to this requirement.</p>

<p>Alternatively, there is the LGPL. This has a library-copyleft clause, where any file that is considered a part of the library must also be released under the LGPL.</p>

software creative-commons open-source-software