Three new proposed OSD terms

Michael Poole mdpoole at
Fri Mar 4 00:51:14 UTC 2005

John Cowan writes:

> Michael Poole scripsit:
> > That is why duplicative or non-reusable licenses are a
> > serious impediment to Open Source.
> I think you overstate the case.  Licenses fall into three groups: simple
> permissive licenses (do what you want with the code, just don't sue);
> reciprocal licenses (your changes have to use my license, but you can
> pretty much incorporate my component into other programs however you like)
> and the GPL.  (I'm adapting, not adopting, Larry Rosen's terminology.)

I would call these groups non-copyleft, weak copyleft and strong
copyleft respectively.  Other OSI approved licenses are also strong
copyleft in that they require larger works to use the same or a
compatible license; the QPL is one example.

> All simple permissive licenses are fully mutually compatible, with
> vanishingly few exceptions.  All reciprocal licenses are compatible with
> each other at the level of assembling components.  Either type may be
> compatible or incompatible with the GPL., sometimes for fundamental
> reasons, sometimes for accidental reasons (patent-peace clauses are
> GPL-incompatible, but hopefully won't be GPL3-incompatible).

Yes, proliferation of strong copyleft licenses causes a problem of
incompatibility that can only be corrected by license changes or
updates.  I should have been more specific that I meant this.

Proliferation of weak or non-copyleft licenses still requires that
somebody do the work to determine license compatibility.  Since that
analysis could be reused, I will concede that that work is not
necessarily a "serious impediment."

> (Note: The SourceForge figures cannot be treated uncritically, because
> many projects are dual-licensed and thus double counted.  I'll bet almost
> all the Artistic License projects are dual-licensed under the GPL.)
> > but a license maze[1] is harsher on both software users and software
> > producers.
> *Users* proper, as opposed to producers who want to *reuse* other people's
> code, don't have to care how many OSI certified licenses there are,
> or which one the program they wish to use is licensed under.  The OSD
> and the OSI between them guarantee that.

Some OSI certified licenses have patent clauses that go beyond what I
would call reasonable patent peace -- APSL, RPSL, MPL v1.1 and others
for termination of all rights triggered by any patent litigation
against someone who contributed to software you use, when the patent
claims are unrelated to any software using an OSI certified license.

Licenses worded like MPL v1.1 are particularly worrying for patent
owners, since they purport to terminate the granted rights as of the
first use, distribution, etc., by the user, rather than as of the
filing of the complaint.  In a way, they work like an "extra strong"
copyleft for patents.

Users who do not own patent rights, or who are not interested in
protecting them, do have it easier.

Michael Poole

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