Rights and attribution
Open does not mean ownerless.
This edition separates the licenses for original prose, software, metadata, and third-party materials so a broad site license never silently relicenses someone else's work.
Textbook prose
CC BY 4.0
Unless a chapter or item says otherwise, original textbook prose may be shared and adapted with attribution.
Website code
MIT
The Astro reader, validation tools, and editor code are available under the MIT License.
Original metadata
CC0 1.0
Original structured records are dedicated to the public domain where legally possible.
Item-level exceptions
Primary-source excerpts, modern translations, Wikipedia-derived prose, Wikimedia Commons images, museum images, and other third-party materials retain the license or use basis recorded on the item. The structured rights registry is generated from the repository's reviewed source records.
Until an item has a verified creator, source, license or public-domain basis, required credit, and stable version, it does not enter the public asset set.