Are implicit dual-licensing agreements inherently anti-open?

[John.Cowan]

David Barrett scripsit:

> The GPL, which I think we can also agree is "open", is at the opposite 
> end of the spectrum.  It explicitly disallows anyone to take code a 
> closed branch -- initial developer or otherwise.

The *copyright owner* can always take his/her/its own code to
a closed branch, whether it is licensed under the GPL or not.
"Copyright [ownership] trumps license."

In fact, it may be possible for a GPL licensor to revoke everyone else's
rights by mere notice, as there is no contract that prevents it -- only
the shaky reed of promissory estoppel.

-- 
The experiences of the past show                John Cowan
that there has always been a discrepancy        jcowan at reutershealth.com
between plans and performance.                  http://www.reutershealth.com
        --Emperor Hirohito, August 1945         http://www.ccil.org/~cowan