When to evaluate dual licenses (was: license categories, was: I'm not supposed to use the ECL v2?)

[Chris Travers]

On Dec 3, 2007 11:19 AM, Chuck Swiger <chuck at codefab.com> wrote:

>
>
> If Postgres also works without GNU readline, or if it also works using
> the BSD-licensed version of libreadline, then it seems clear enough
> that Postgres by itself is not a derivative work of GNU readline.
> However, a precompiled binary which statically links in GNU readline
> clearly would be.


It does but not pleasantly.  Nobody in their right mind would run it that
way given a choice.

>
>
> The same would apply to a proprietary closed-source program-- if it
> ships as a binary which statically links in GNU readline, than they
> need to honor the GPL and release their sources.  The interesting case
> is what happens if a proprietary binary works fine as is, but is
> willing to dynamically load libreadline if available.  :-)


This is not the FSF's view (they claim that even optional use of Readline
means that the program falls under the requirements of the GPL).  If the
license is compatible, though (as it is in PostgreSQL's case) then there
isn't a problem.  Note that this probably means you can use BSD-licensed
bridges to proprietary code with no problems (you just treat it as GPL +
linking exceptions).  This is the issue-- if the FSF pushes the issue, then
they suggest that linking exceptions cannot be added to works which use
their libraries.

Best Wishes,
Chris Travers
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opensource.org/pipermail/license-discuss_lists.opensource.org/attachments/20071203/67fad1ee/attachment.html>