[Savannah-hackers-public] Re: [gnu.org #548720] Explanation about permissive licences?

[Karl Berry]

Hi Mario,

    If me or some other person modify a file under the revised BSD licence
    can he licence the result under any other licence he chose

He can't change the license of the original code.  He can license his
own new code in any compatible way.

As a matter of practicality and courtesy, in GNU we generally recommend
that modifications to RBSD'd code also be licensed under RBSD.  (Ditto
for any similar permissive free software license.)

     (Including propietary ones)?.

RBSD code can be used in proprietary programs.  However, it's not that
the RBSD code is being relicensed, but rather the RBSD is compatible
with essentially anything, including proprietary terms.  The original
code still exists, and it is still under RBSD.

    Is required I put an separator something like "The original file is
    licenced as follows: [...]"?.

If different licenses are involved, it's required to state which
licenses apply to which parts.
    
    Do the same apply for the following licence or what are the
    differences?:

Looks like the ISC/OpenBSD license.  The wording is suboptimal, because
of UW's prior weird interpretation of that phrasing ("use, copy, modify,
and[/or] distribute").  We recommend using Expat or FreeBSD instead.
See http://www.gnu.org/licenses/license-list.html#ISC.

Anyway, yes, the same sort of thing of applies to all permissive free
software licenses.

    In both cases Won't the requirement to retain that notice qualify a
    "futher restriction"?

Assuming you mean a "further restriction" in GPL terms: no, because the
GPL already requires that you keep intact notices in unmodified code,
and update notices in modified code as needed.  So it's not "further".

As a general rule: you can take
http://www.gnu.org/licenses/license-list.html as gospel.  It does not
get changed without a lot of reviews and approvals (by rms, among
others).

RBSD is listed on that page as compatible with the GPL.  Therefore, you
can ask yourself, "why is it compatible?", instead of thinking "wow,
this looks like a further restriction, so it should be  incompatible".

Hope this helps.  Best regards,
address@hidden

Disclaimer: I am not a lawyer, and this is not official legal advice.