IANAL, but I believe you cannot put "(c) Your Name 2020" on Shakespeare's works in Japan and other countries. Their copyright acts protect the moral rights of authors[1][2]. So I think Zen's file headers would be violating the law in Japan and other countries.

[1] https://en.wikipedia.org/wiki/Moral_rights [2] http://www.japaneselawtranslation.go.jp/law/detail_main?id=2... (Copyright Act of Japan) Subsection 2 Moral Rights of Authors (Articles 18 to 20)

You have it backwards. The MIT/Expat does required you to retain a copyright notice (in the form of a copy of the license, not in the form of file headers), which Zen does. In addition, creating a derivative work does in fact give you copyright on the new work. The Shakespeare comparison does not apply because Shakespeare is not licensed under the MIT/Expat license.

> MIT/Expat does required you to retain a copyright notice (in the form of a copy of the license, not in the form of file headers)

OK, but I was talking about the file headers. :)

> In addition, creating a derivative work does in fact give you copyright on the new work

Sure, but the new work is the portions that you've changed, not the portions that you've copied, right?

"The derivative work cannot be an uncreative variation on the pre-existing work or it would simply be a copy of the pre-existing work . . . " from here: https://bit.ly/3c21Yul

>OK, but I was talking about the file headers. :)

Gotcha, then you are correct. The MIT/Expat only requires: "The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software". As long as they are in compliance on that regard then they are in the clear.

>Sure, but the new work is the portions that you've changed, not the portions that you've copied, right?

No, the new work is the piece of software work as a whole, not the individual files. "Work" in this context is a legal term that includes all of the source code and nonliteral elements of the software, aka the Structure, Sequence, and Organization https://en.wikipedia.org/wiki/Structure,_sequence_and_organi...

R.e. your second statement, I can only presume that you're right, but I'm confused about how this works with copyright license agreements, or the cases where projects have had to go and get copyright releases from authors of individual lines of code to make a license change. If the copyright is on the entire work, how can a contributor of just one line of code own the copyright? Anyway. You seem more versed in this than I am, so I bow to your expertise.

In that case, there would be multiple authors of a single copyrighted work. I'm only familiar/knowledgeable with GNU copyright assignment, however, not copyrights in general. https://www.gnu.org/licenses/why-assign.en.html

> I suspect that the license may not require you to retain the notices

It explicitly does.

Just read the MIT license. Doesn't say anything about file headers.

It doesn't need to say anything about file headers. A source file is a copyrightable work. The copyright notice and license file in that source file provide the copyright notice for that work and it's licensing terms. The MIT license, under which the work is licensed, requires the copyright notice of the work to be preserved. By removing and replacing the notice on the work, and distributing it without preserving the original notice as required by the license on the work, the license is violated.

The fact that the work is also included in a compilation, which is a separate copyright protected work, and that work has its own copyright notice and is offered under the same license, does not somehow alter the license requirements on the component work within the compilation, so that of the compilation’s copyright is preserved as required by the license of the compilation, there is no obligation to preserve the copyright notice of the component work as required by the license on the component.