Can GPLv3 packages be synced?

[Stephen J. Turnbull]

Mats Lidell writes:

 > I have just released a version of Hyperbole under GPLv3. Can I sync
 > this with the XEmacs Package Tree or need I maintain a v2 version in
 > parallel for now?

As long as all code is either "legacy" GPLv2-or-later code, or under
your authorship, you can dual-license.[1]  This would be helpful to us
while we figure out what to do about GPLv3 and the main part of
XEmacs.  In particular we need to make sure that there are no more Bob
Weiner surprises (GPLv2-only) waiting for us.

 > How will the board go about the GPLv3 issue?

Thanks to Michael Albinus, we have an opinion from the FSF Copyright
clerk.  Basically, it's complex but under some circumstances we can
distribute packages under GPLv3 without relicensing either other
packages or the core XEmacs.  The main consideration, I think, is
political: what Richard Stallman will think.  I doubt he'll like it
very much.

I don't really think we have much choice, but we do need to check that
everything can be promoted to GPLv3, and do something about anything
that can't be promoted.


Footnotes: 
[1]  If you've assigned to the FSF, you may need to notify them, but
all assignments I've seen require the FSF to either license as you
request, or give you permission to "use as you see fit."