Revocable or non-revocable licenses from AdaCore? (Re: AdaCore ... the Next SCO?)

[Jacob Sparre Andersen <sparre@nbi.dk>]

Ludovic Brenta wrote:

> - because license terms can change with the weather, or be different
> for each licensee. They can even change after a licensee has had a
> license for some time.
>
> This is true of all software, free or proprietary, cost or no cost.

Not quite.  GPL, LGPL and GMGPL are all explicitly non-revocable.
AdaCore _cannot_ change a license after it has been given, if it is
one of these three - no matter what they claim.

> So basically, the user needs assurance about two things: who the
> copyright holder really is, and what license terms are applicable at
> any given point in time and for this particular licensee.

If a file for a long time has been available for download from the
copyright holder's own web site with a clear and consistent license
notice, then I doubt very much that there is any doubt about which
license you have it under if you have downloaded it during that
period.

> To give proper assurance on both accounts, I think that the
> copyright holder should crypto-sign his software, and grant a
> perpetual, non-revokable, immutable license to
> everyone. Unfortunately, the GPL (GNAT-modified or not) is revokable
> and mutable (think "or any later version"), so it is possible that
> it not apply to all licensees.

GPL is _not_ revokable.  The "or any later version" clause is purely
an option for the licensee, not something the copyright holder can
use.

Greetings,

Jacob
-- 
�Saving keystrokes is the job of the text editor, not the
 programming language.�                    -- Preben Randhol