If you share work that you created publicly online, and you want to give others the option to further share and use it, make sure to include an open license. Open licenses are free tools that let authors know upfront how much or how little they can use, share, and adapt each other’s work. When you use or remix work in a way that is permissible under an open license, you do not need to contact its author.
For sharing open-source software that you have authored, the most popular options are the MIT License and the GNU GPLv3 license. The MIT license is brief, while the GNU GPLv3 license is lengthy. Make sure you read and understand a license before you apply it.
For non-software projects, including creative work and datasets, you'll likely want to apply a Creative Commons license. There are six in total, each with a different level of allowability for sharing, remixing, and reproducing the protected content.
Choosealicense.com provides a helpful breakdown of the different options.
Authors can apply an open license to their work by indicating it within their work. For software projects, add a text file containing the text of the license to the root of your source code. Consider also adding a CITATION.cff file to your software when you share it online. This file format lets users and computers quickly know what license you are applying and how exactly to cite your work. For non-software projects, say which license you are applying and link out to that license.
For example, here is how we have applied a license to this LibGuide:
This guide by Digital Projects Lab is licensed under CC BY 4.0.
Now that we have attached that sentence to this guide, we have applied the license we want to it. We have specified that any users who want to reuse or remix this guide must reference and link back to it.
If you do not want to give others the option to share or reuse your original work, you don't have to. From the US Copyright office: "Copyright protection in the United States exists automatically from the moment the original work of authorship is fixed." So you reserve exclusive rights to reproduce, perform, distribute, and create derivatives of anything you create that qualifies as "original works of authorship," without the need to register it or declare a copyright statement with your work. If and when you apply an open license to your work, only then will you be sharing the rights to your creative work.
Learn more:
If you plan to share software you created that uses or references another author's software, it is essential to properly attribute the author. To do this, determine if the original software is licensed with either a permissive or a copyleft open software license. Then, following the corresponding guidelines, include the appropriate statements of changes, notice file, copyright notice, and license text in the set of files containing your code. For example, if publishing code to a GitHub repository, include files in the repository called "LICENSE", "CITATION," etc.
Permissive licenses, like Apache 2.0 License and MIT Licensed, allow users to make changes, additions, to create new programs, and to distribute their work. For example, the Apache License 2.0 requires distributed code that uses the license to 1. state any major changes made to the original code and 2. include a copy of the notice file with attribution notes, along with the copyright notice and license text.
Copyleft licenses like GNU-GPL similarly allow users to make changes, additions, combine, and redistribute, but with the caveat that all resulting code must be licensed under the same license.
If you plan to share or remix a Creative Commons licensed work, do so by sharing the Title, Author, Source, and License for that work. Include a link to the original page and to the license deed. Link to the author's profile if available. For example:
This page was adapted from "Open Licenses: Creative Commons and other options for sharing your work" by Jonah McAllister-Erickson, which is licensed under CC BY 4.0. Visit the source to learn more.
