[Coin-discuss] COIN-OR licences again...

Sun Apr 6 22:31:01 EDT 2008

On Sun, 2008-04-06 at 19:33 -0400, Alan King wrote:
> 
> I believe the CPL is compatible with the Debian Free Software
> Guidelines.  See http://www.debian.org/social_contract#guidelines.   
> The numbering below is from DFSG 
> 

CPL is also an Open Source license according to the criteria at
http://www.opensource.org.  Those guidelines are based on the DFSG, so I
think it is quite unlikely that a license that complies with one would
not comply with the other.

>     1. CPL grants license to reproduce, distribute, sublicense, and
> sell.  No royalties are required. 
> 
>     2. CPL permits redistribution of source code and object code,
> provided the CPL license is included in source code and copyright
> notices are not altered. 
> 
>     3. CPL permits modification and redistribution under CPL license.
> It even allows redistribution under other licenses, provided those
> licenses have appropriate disclaimers and states that recipients have
> access to source code. 
> 
>     4. Integrity of derivative works is not required by CPL. 
> 
>     5-6. CPL grant is without restrictions. 
> 
>     7. The rights are granted no matter how the software is obtained. 
> 
>     8.  License is not specific to Debian. 
> 
>     9.  CPL does not contaminate other software (a question: GPL'd
> software does not comply with this requirement...I suppose DFSG is a
> work in progress). 
> 
> I also see no problem releasing COIN under GPL provided the provisions
> 3.b(i-iv) in CPL are stated in the License somewhere.  But as I say, I
> don't think GPL meets the DFSG requirement #9. 

The heading of the corresponding requirement of the Open Source
Definition is worded better, I think.  It states:

        9. License Must Not Restrict Other Software

Compare with the DFSG version:

        9. License Must Not Contaminate Other Software

The explanatory text is identical in both versions:

        The license must not place restrictions on other software that
        is distributed along with the licensed software. For example,
        the license must not insist that all other programs distributed
        on the same medium must be open-source software.

I believe the intent is not to prevent the GPL's "contamination" of
other code in a derived work or "work as a whole", but to prevent the
license of one distinct product from imposing requirements on other
distinct products distributed on the same medium or from the same
source.

>From my reading of the old discussion (circa GPL v2) on the FSF page,
the patent protection clauses (perhaps including clause 3.b) are what
made the CPL incompatible with the GPL v2.  The FSF said they didn't
think the clause was a bad idea, but it was still incompatible.  

The new discussion (for GPL v3) says that the incompatibility still
exists, but is now due to the "choice of law" clause.  I haven't
identified the exact wording at issue.  The FSF also says that the CPL
*is* a "free software license".  (See
http://www.fsf.org/licensing/licenses/index_html.)

>  
> Alan 

As to Soeren's initial question, see below.

> Soeren Sonnenburg
> <Soeren.Sonnenburg at first.fraunhofer.de> 
> Sent by:
> coin-discuss-bounces at list.coin-or.org 
> 
> 04/06/2008 05:56 PM 
> 
> 
>                To
> coin-discuss at list.coin-or.org 
>                cc
> 
>           Subject
> [Coin-discuss]
> COIN-OR licences
> again...
> 
> 
> 
> 
> 
> 
> 
> 
> Dear all,
> 
> I apologize for bringing up this discussion again, but is there any
> chance that the COIN OR projects under is dual licensed under CPL
> *and*
> the GPL? (The CPL is GPL incompatible and thus COIN-OR with 90% of the
> open source programs, not even *linking* to a CPL based library is
> OK).
> 
> I am asking as I would love to see the COIN libraries to be more
> widespread, i.e. 
> 
> a) I am interested in packaging some of the coin-or programs for
> debian. For example I already packaged dsdp (as it is GPL). It is not
> clear whether the CPL license is debian free software guidelinces
> conform so I would very much like to see coin-or projects GPL dual
> licensed... Note that debian based distributions have the biggest
> market
> share among the linux distributions - so coin-or could be
> pre-installed
> and may actually be used by a larger audience.
> 
> b) I personally am looking for a free linear optimizer (like Clp) or
> even the Open Solver Interface (OSI) to be used in my shogun toolbox
> (www.shogun-toolbox.org) to at some point get rid of a cplex
> dependency.
> I know I could use glpk or lpsolve but as COIN is widely known in the
> OR
> community I would prefer seeing its projects to be dual licensed. And
> OSI is a great idea, but what does it help if you are not allowed to
> use
> it in an open source project due to licensing conflicts?

Given the above, what is the issue you have with the CPL?

It's true that there are some restrictions we have to live with.  For
example, we can't distribute binaries linked with GNU readline or GLPK.
The onus is on the recipients of the code to build such binaries if they
want those features.

The discussions on the COIN-OR board related to dual licensing are
continuing, but given Alan's comment about clause 3.b, I'm not sure what
progress we could make with IBM (who owns the code contributed by
members of its staff).

As for linking with your own code, if you control the license, you could
consider an exception to the GPL along the lines of the MySQL one
(http://www.mysql.com/about/legal/licensing/foss-exception.html), which
would allow distributing binaries linking your code to CPL code.  That
exception was created so that the GPL version of MySQL libraries could
still be linked to PHP.
> 
> Please note that it is in any case not a good idea to use a GPL
> incompatible license (see e.g.
> http://www.dwheeler.com/essays/gpl-compatible.html)
> After all most of the projects are GPL and a further incompatibility
> between open source licenses does not really help...
> Maybe this was one of the reasons why firefox etc are now dual
> licensed
> under GPL/LGPL/MPL... I understand that IBM started this project and
> some people simply did not like the GPL and *intentionally* choose the
> CPL. The community just suffers from conflicting licenses so I hope we
> can overcome this...

The reasons that some people don't want to use or create GPL code
involve more or less legitimate concerns on their part.  I can't speak
for IBM, for sure, but it's clear to me that they developed the CPL at
least in part because they were concerned about patent protection that
wasn't part of the GPL v2.  

The most common concern with the GPL is the requirement that the "work
as a whole" be licensed under the GPL if any part is, even if that part
is only linked through a clean, well-defined interface.  That makes
creation of all kinds of interesting combinations of tools impossible to
distribute in ready-to-use form, as you are aware.

> 
> Soeren
> -- 
> Soeren Sonnenburg - Fraunhofer FIRST      Tel: +49 (30) 6392 1882
> Kekulestr. 7, 12489 Berlin, Germany       Fax: +49 (30) 6392 1805

-- 
                Matthew Saltzman

Clemson University Math Sciences
mjs AT clemson DOT edu
http://www.math.clemson.edu/~mjs