Licences
Every book here carries a licence, and the licence decides what you may do with the book. All of them let you read, download and share it free of charge; they differ on changing the book and on commercial use.
Public domain Public Domain
Copyright has expired. Anyone may copy, share and adapt the work for any purpose, without asking.
- Commercial use allowed
- Changes and translations allowed
CC0 CC0 1.0 – Public Domain Dedication
The owner has given up all rights and dedicated the work to the public domain. No conditions at all, not even attribution.
- Commercial use allowed
- Changes and translations allowed
CC BY Creative Commons Attribution 4.0 (CC BY)
Copy, share and adapt the book for any purpose, even commercially, as long as you credit the author.
- Commercial use allowed
- Changes and translations allowed
CC BY-SA Creative Commons Attribution-ShareAlike 4.0 (CC BY-SA)
Credit the author, and if you adapt the book you must release your version under this same licence. Commercial use is allowed.
- Commercial use allowed
- Changes and translations allowed
CC BY-NC Creative Commons Attribution-NonCommercial 4.0 (CC BY-NC)
Copy, share and adapt the book with credit to the author, but not for commercial purposes.
- No commercial use
- Changes and translations allowed
CC BY-NC-SA Creative Commons Attribution-NonCommercial-ShareAlike 4.0 (CC BY-NC-SA)
Credit the author, no commercial use, and adapted versions must carry this same licence.
- No commercial use
- Changes and translations allowed
CC BY-ND Creative Commons Attribution-NoDerivatives 4.0 (CC BY-ND)
Copy and share the whole book unchanged, with credit to the author. Changed versions may not be shared.
- Commercial use allowed
- No changes allowed
CC BY-NC-ND Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 (CC BY-NC-ND)
The most restrictive: share the unchanged book, with credit, for non-commercial purposes only.
- No commercial use
- No changes allowed
What is the public domain?
Copyright does not last for ever. Under Sri Lanka's Intellectual Property Act, No. 36 of 2003, the economic rights in a work last for the author's life and 70 years after the author's death. After that the work is in the public domain, and anyone may freely copy, share and reprint it. That is why every book marked "public domain" here shows the year its author died.
The law differs between countries. If you are outside Sri Lanka, consider your own country's rules as well. This is not legal advice.