Is using the GPLv3 without putting a license notice in each source file OK?

Question

I have published code on GitHub with the following license:

Quantum including:

Main.scala
 Enrichment/
  package.scala
 Graphics/
  Canvas.scala
 Math/
  Immutable/
   Matrix.scala
   Quaternion.scala
   Vector2.scala
   Vector3.scala
  Mutable/
   Matrix.scala
 Universe/
  package.scala
  Space.scala

Quantum is a point grid rendering algorithm written in Scala

Copyright (C) 2018 Markus Appel

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, see http://www.gnu.org/licenses/gpl-3.0

I am available for any questions/requests: [email protected]

The layout of this license does not match any "best practices" and tutorials. But I do not like these, mainly because they want me to add multiple lines of legal notice in every file.

For me, that is almost unacceptable.

So, best practices aside, is this a valid license?

Answer 1

The GPL FAQ indicates this is legally valid but not advised for practical reasons:

A clear statement [about GPL licensing] in the program's README file is legally sufficient as long as that accompanies the code, but it is easy for them to get separated.

This FAQ item goes into more depth:

Why should I put a license notice in each source file?

You should put a notice at the start of each source file, stating what license it carries, in order to avoid risk of the code's getting disconnected from its license. If your repository's README says that source file is under the GNU GPL, what happens if someone copies that file to another program? That other context may not show what the file's license is. It may appear to have some other license, or no license at all (which would make the code nonfree).

Adding a copyright notice and a license notice at the start of each source file is easy and makes such confusion unlikely.

The GNU Project's advice here is based entirely on a concern about future modifications separating code from its licensing information, not about the validity of the license grant.

Answer 2

There is some software, and I assume that the copyright belongs to one Markus Appel. Being the copyright holder, it is his exclusive right to allow you or not allow you to make copies of the software, and it is his exclusive right to allow you or not allow you to create derived works of the software. He also is allowed to allow you to do these things under any conditions he likes (within very wide limits).

Your right is to take it or leave it. That is, you have the right to not copy his software, and not create derived works of his software, or to make copies and/or create derived works, while following any conditions that he sets.

If you find his conditions unacceptable, then you can't copy the software or create derived works. Should a judge decide that the license is illegal, then you lose as well, because there would be no legal license, which means you don't have the right to copy the software or create derived works.