Open textbooks. Free to read. Open to improve.

High-quality learning materials for elementary school through university — on the web, at no cost.

  • Free means the whole book, for everyone — read it all online without paywalls.
  • Open means open source — anyone can fix a typo, add a chapter, or fork a book on GitHub.

Catalog

Browse by subject

Mathematics

Coming soon

Algebra, calculus, statistics, and more — structured for self-study and classrooms.

Science

Coming soon

Physics, chemistry, biology, and earth science from introductory to advanced levels.

Humanities

Coming soon

History, literature, philosophy, and languages — readable, citable, and free to share.

Computing

Coming soon

Programming, computer science fundamentals, and practical skills for students and teachers.

Subject pages and full catalogs are on the roadmap. Contribute a book on GitHub.