Implications for switching licenses mid-stream

[Ben Tilly]

On Mon, Apr 21, 2008 at 11:12 PM, Arnoud Engelfriet
<arnoud at engelfriet.net> wrote:
> Jon Lesser wrote:
[...]
>  And by the way, you need permission from all contributors to switch
>  to Y, but you probably knew that.

Not always true!

In the case of BSD to GPLv3 you don't need explicit permission from
anyone because the BSD already grants sufficient provision.

In the case of "GPLv2 or later" to GPLv3 you don't need permission for
the same reason.

In the case of GPLv2 to GPLv3 you do need some sort of permission.
But from what I've read, you _may_ need less (at least in US law) than
many have assumed.  See
http://catb.org/~esr/Licensing-HOWTO.html#changing for further
discussion.  I have no idea how that plays out internationally.  And
you should talk with a lawyer before applying that theory to a
specific project.

Ben