[wickedchicken]

> That's like having a clause in the GPL that says at any given time, the author can revoke the GPL and sell the copyright to Microsoft.

Which, unless the author has specifically assigned copyright to someone else, you can totally do. A similar situation arises with dual-licensed software. Of course, older versions of the software still 'live on' under the GPL, the author is implicitly making a fork.

This is one of the reasons the FSF wants you to assign it copyright to stuff: http://www.gnu.org/licenses/gpl-faq.html#AssignCopyright

[drcube]

>Of course, older versions of the software still 'live on' under the GPL, the author is implicitly making a fork.

That's what I'm talking about, though. You can't say "Everybody that has previously used or is currently using this software under the terms of the GPL now owes me a crapload of money -- and by the way, the GPL is revoked and you must abide by the Microsoft EULA".

But that seems, to my untrained eye, to be exactly what this Twitter patent promotes. It's basically saying "We won't sue you now, but we reserve the right to do so at any time in the future. So keep your grubby mitts off our IP." Really, it's no different than the status quo.

[PotatoEngineer]

No, the point is that all of the current & older versions of software would still be GPL. Only the author's next release (possibly released today) would be under different licensing terms. You can't revoke the GPL.