[logback-dev] Copyright headers

ceki ceki at qos.ch
Mon Jun 18 13:09:17 CEST 2012


On 16.06.2012 01:18, Ralph Goers wrote:
> I guess you missed the discussion where Ceki decided to dual license
> Logback under the LGPL and EPL just so you could do this.  You can use
> Logback for unit tests at the ASF.  That said, I'd prefer you to use
> Log4j 2.0.

Ironically enough, Les is one of the persons who broached the issue of 
using logback in Apache projects. (see his email [1] dated September 3rd 
2009).

On September 9th 2009, Ralph rightly asked me to close LEGAL-63 [2]. In 
my reply to Ralph [3], I wrote:

   ..., the theoretical case of an LGPLed library implementing a
   standard (licensed under a liberal license) remains valuable. It
   illustrates LGPL's requirements on reverse engineering. For example,

   Let FooCorp be a company and Frobber be some software developed by
   FooCorp. Frobber codes against the SLF4J API without ever directly
   referencing logback. Can FooCorp distribute Frobber with an unmodified
   version of logback (our LGPLed library). Does the LGPL require FooCorp
   to allow users to reverse engineer Frobber for their own use? Keep in
   mind that Frobber usage of logback in Frobber is isolated behind the
   SLF4J API.

   The answer to that question is *surprisingly* yes, although with some
   qualifications too hairy to be mentioned. FooCorp is required to allow
   reverse engineering of logback in the software license for
   Frobber. This follows from discussions with Luigi Bai, an FSF
   volunteer, and is also documented by the Free Software licensing quiz
   (see http://www.gnu.org/cgi-bin/license-quiz.cgi ), in particular
   question 8, which reads:

   Question: FooCorp [a company] distributes Frobber [software developed
   by FooCord] linked against an unmodified version of LibIdo [an LGPL
   library]. Does the LGPL require FooCorp to allow users to reverse
   engineer Frobber for their own use?

   Correct answer: Yes.

   I still have my doubts about the applicability of the
   reverse-engineering clause but the FSF thinks otherwise, as insofar
   as an organization can think. FSF's interpretation is in turn echoed
   by defensive measures by others, e.g. the ASF. The LGPL is a little
   less liberal than what it seems initially. It is what it is, neither
   good or bad. Nevertheless, the mere fact that the reverse-engineering
   question is so convoluted and shrouded in layers of gobbledygook, is
   one of the principal reasons for dual-licensing logback.

As I find FSF's interpretation of the LGPL unreasonable (but they are
the guardians of LGPL so their interpretation matters), I decided to
dual-license logback under LGPL (for backwards legal compatibility)
and EPL (a less vindicative/more reasonable reciprocal license).


[1] http://tinyurl.com/nsj6wf
[2] https://issues.apache.org/jira/browse/LEGAL-63
[3] http://tinyurl.com/cu6hpso

> Ralph


-- 
Ceki
http://twitter.com/#!/ceki


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