IBM Public Source License
I sent this off to the folks at IBM.
On the firstname.lastname@example.org mailing list, they have been discussing
the IBM Public Source License as released for the Postfix mailer. There is a
question of interpretation regarding the following:
iii) states that any provisions which differ from this Agreement
are offered by that Contributor alone and not by any other
The question regards redistribution of an object-code work under a different
agreement than the IBM Public Source License. Party A distributes an
object-code work to B. A's license differs from the IBM Public Source License,
and A's license provisions require B to pass on the work to all third parties
using the same license provisions as A's license, and so on to all subsequent
parties ad infinitum. Party B redistributes it to party C. C asks B to honor a
provision of A's license. Is B obligated to, because B is redistributing a work
he got from A under A's terms, or do A's provisions not apply to _any_ other
party, _even_ another party to whom A redistributes the work?
This is in the context of an IBM Public Source License work being combined with
a work under the GNU General Public License for distribution in object code.
The GPL requires that anyone who redistributes a GPL-ed work do so under the
GPL and honor the obligations in the GPL to all parties to whom they
redistribute the work, and so on to all subsequent parties ad infinitum.
One reader feels that the IBM Public Source License provision quoted above
would prohibit this provision of the GPL, and thus works under those two
licenses can not be combined. I don't agree with his interpretation, but
given that programmers, not attorneys, have to execute this license, anything
that reads ambiguously to those programmers should be cleared up.
The discussion is excerpted below.
> A Contributor may choose to distribute the Program in object code form
> under its own license agreement, provided that:
> a) it complies with the terms and conditions of this Agreement; and
> b) its license agreement:
> iii) states that any provisions which differ from this Agreement
> are offered by that Contributor alone and not by any other
> party; and
>This makes it not compatible with the GPL, since the GPL requires that
>the terms you distribute it under apply to all third parties, while
>this IBM license does not.
Bruce Perens <email@example.com> wrote:
> You could make it GPL compatible. The quoted clause applies to
> parallel contributors and does not prevent subsequent contributors
> from continuing to honor your license.
> I don't see where the license makes that kind of distinction.