Creative Commons Attribution-ShareAlike 4.0 International License
Contents
The Creative Commons Attribution-ShareAlike 4.0 International License (often abbreviated as CC BY-SA 4.0) is a widely used Creative Commons public copyright license. It allows others to distribute, remix, adapt, and build upon the licensed material, even commercially, as long as they give attribution to the original creator and license their new creations under identical terms.
This license is designed to ensure that derivatives of the work remain freely available under the same conditions as the original. It is a "copyleft" license, meaning that any derivative works must also be shared under the CC BY-SA 4.0 license.
Key Elements
The CC BY-SA 4.0 license is built upon two core elements:
- Attribution (BY): This element requires that anyone who uses, distributes, or creates derivative works from the licensed material must give appropriate credit to the original creator. This includes providing a link to the license, indicating if changes were made, and linking to the original work.
- ShareAlike (SA): This element mandates that if you remix, transform, or build upon the material, you must distribute your contributions under the same license (CC BY-SA 4.0) as the original. This ensures that the freedom to share and adapt the work is preserved for all future users.
Features and Benefits
- International Applicability: The "4.0 International" version is designed to be globally applicable, making it suitable for use across different jurisdictions.
- Human-Readable and Legally Sound: Like all Creative Commons licenses, it comes in three layers: the "Legal Code" (the full legal text), the "Deed" (a human-readable summary), and the "Digital Code" (machine-readable metadata).
- Promotes Openness: By requiring derivative works to be shared under the same terms, it fosters a growing pool of openly licensed content.
- Flexibility for Commercial Use: Unlike some other Creative Commons licenses, CC BY-SA 4.0 permits commercial use of the licensed material, provided the attribution and ShareAlike conditions are met.
Use Cases
CC BY-SA 4.0 is commonly used for:
- Wikis and Collaborative Platforms: Many wikis, including Wikipedia, use a CC BY-SA license (often an earlier version like 3.0 or 4.0) for their textual content to ensure contributions remain freely shareable and modifiable.
- Educational Resources: Open educational resources (OER) often use this license to facilitate adaptation and sharing among educators and students.
- Open Source Software Documentation: Documentation for open-source projects.
- Creative Works: Music, art, photography, and literature where the creator wants to encourage remixing and sharing.
- Public Data and Research: Datasets and research findings that benefit from broad dissemination and adaptation.
Comparison with Other Licenses
- vs. CC BY (Attribution Only): CC BY-SA adds the "ShareAlike" condition, meaning derivatives must carry the same license. CC BY allows derivatives to be licensed under different terms.
- vs. CC BY-NC-SA (NonCommercial ShareAlike): CC BY-SA allows commercial use, whereas CC BY-NC-SA restricts it.
- vs. Public Domain: Public domain works have no copyright restrictions. CC BY-SA 4.0 still retains copyright but grants broad permissions under specific conditions.
How to Apply the License
To apply the CC BY-SA 4.0 license to your work, you typically include a notice with the work that states: "This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License." It is also good practice to include a link to the license deed: `https://creativecommons.org/licenses/by-sa/4.0/`
