Re: Update some sim copyright headers to GPLv3-or-later

[ams at gnu dot org (Alfred M. Szmidt)]

   > > As per a request from the FSF, I have updated the copyright
   > > headers of the non-FSF-copyrighted files from "GPL v2 or later"
   > > to "GPL v3 or later".
   > 
   > You can't do this without asking the copyright holders for
   > permission first.

   I was told the contrary by Karl Berry, and asked to change.  IANAL,
   but the "or (at your option) any later version" should give us the
   right to do so, right?

That is correct, here is a snippet from the GPL FAQ.  Though it is
only OK if the license either states "or any later version", or lacks
an explicit version -- then one may pick any version of the GPL.

| Why should programs say â??Version 2 of the GPL or any later versionâ???
|
|     From time to time, at intervals of years, we change the
|     GPLâ??sometimes to clarify it, sometimes to permit certain kinds of
|     use not previously permitted, and sometimes to tighten up a
|     requirement. (The last change was in 1991.) Using this â??indirect
|     pointerâ?? in each program makes it possible for us to change the
|     distribution terms on the entire collection of GNU software, when
|     we update the GPL.
|
|     If each program lacked the indirect pointer, we would be forced to
|     discuss the change at length with numerous copyright holders,
|     which would be a virtual impossibility. In practice, the chance of
|     having uniform distribution terms for GNU software would be nil.
|
|     Suppose a program says â??Version 2 of the GPL or any later versionâ??
|     and a new version of the GPL is released. If the new GPL version
|     gives additional permission, that permission will be available
|     immediately to all the users of the program. But if the new GPL
|     version has a tighter requirement, it will not restrict use of the
|     current version of the program, because it can still be used under
|     GPL version 2. When a program says â??Version 2 of the GPL or any
|     later versionâ??, users will always be permitted to use it, and even
|     change it, according to the terms of GPL version 2â??even after
|     later versions of the GPL are available.
|
|     If a tighter requirement in a new version of the GPL need not be
|     obeyed for existing software, how is it useful? Once GPL version 3
|     is available, the developers of most GPL-covered programs will
|     release subsequent versions of their programs specifying â??Version
|     3 of the GPL or any later versionâ??. Then users will have to follow
|     the tighter requirements in GPL version 3, for subsequent versions
|     of the program.
|
|     However, developers are not obligated to do this; developers can
|     continue allowing use of the previous version of the GPL, if that
|     is their preference.