Licensing open-source code and art assets

Question

I want to build a permissively-licensed web site, but preserve copyright for art assets included in the repo.

How do open software licenses differentiate between code and art assets/content? Recognizing that all licenses are different, are there any useful general guidelines for what is and isn't covered by a software license?

Answer 1

Licenses aren't all-or-nothing. However, its useful to keep material under different licenses clearly separate. For example, your web site might have multiple directories: backend, js, assets, content. You could then clarify that different licenses apply to different parts:

LICENSE.txt:

Some Pretty Website
Copyright 2021 Some Person

The material in backend/ and js/ is licensed under the MIT license, see LICENSE.MIT.txt.

The material in assets/ is licensed under the CC-BY-NC-ND license 4.0, with the exception of the following assets:

• assets/stock-photo.jpg: public domain image from Some Website.
• assets/wikipedia.png: Wikipedia-logo-v2.svg by Nohat (CC-BY-SA 3.0 license).

The material in content/ is all rights reserved, and included for reference only.

In textual files, it might be possible to clarify the file's license with a machine-readable SPDX-License-Identifier comment.

In many cases, it will be less confusing to have different repositories for parts under different licenses. If there's only one applicable license, automated tools (like the auto-detected repository license field on GitHub) will be more accurate.

Note that in any case, you do retain your copyright. Open-source licenses work because you have a copyright: you as the copyright holder give certain permissions to the public. You are not bound by your licenses yourself. E.g. you can give a copy of your code to one person under the GPL license, another copy to someone else under the MIT license, and even sell a proprietary non-exclusive license to a another party.