Re: [eigen] copyright / license question

[Cyrille Berger <cberger@xxxxxxxxxxx>]

On Monday 03 November 2008, Benoît Jacob wrote:
> Hum wait, being "compatible" doesn't mean "allow to relicense", for example
> BSD is GPL-compatible but one can't relicense from BSD to GPL (see e.g. the
> fuss that happened when a linux driver developer mistakenly relicensed
> OpenBSD code to GPL in a wifi driver).
We are moving a little bit off topic :)

Hum, that's the other way around, the wifi driver was GPL code, an OpenBSD dev 
was working on BSD version and during his developement he was using GPL code 
from an other driver but he had wiped out the GPL license to put BSD, which 
is wrong. And the second clash was for an other driver which was available as 
a dual license BSD + GPL, and someone decided to include it in linux and drop 
the BSD license (which I find extremely rude but which is completely allowed 
by a dual license scheme, otherwise what the point ?), but Theo, the OpenBSD 
leader, have a deep hatred of the FSF and Linux, and find there the occasion 
to take revenge on linux on what have happened during the wifi driver using 
GPL-code-under-BSD.

So yes beeing compatible with GPL means the possibility to add the clauses of 
the GPL that aren't in the original license (which prevents GPLv2 and GPLv3 
to be compatible) and that the clause of the license are included in GPL. So 
if you take BSD code, and write modification, your modification can be under 
the GPL. This effectively relicense the file to GPL, if you want to stay safe 
you can keep the BSD copyright header, and just add GPL header in the file, 
but since BSD clauses are contains in GPL, well it's not really necesserary.

-- 
Cyrille Berger

---