[m-dev.] [m-users.] Closed source Mercury projects on Windows

[Peter Wang]

On Mon, 28 May 2018 10:25:54 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> 
> Hi Mark,
> 
> On Sun, 27 May 2018, Mark Brown wrote:
> 
...
> 
> Actually, the Ocaml license may provide a better model for this:
> <https://ocaml.org/docs/license.html>.
> 
> >> My own feeling is that rather than using a modified LGPL, it would be
> >> more straightforward to relicense the runtime, stdlib etc under the
> >> BSD or MIT license.
> >
> > How would that be more straightforward than relicensing it under the
> > wxWindows license?
> >
> > I think the wxWindows license reflects what contributors - going back
> > a long way, mind you - actually intended from the library license, so
> > I'm pretty comfortable changing to that to address the technical
> > issues. But I don't see that the same can be said of BSD or MIT.
> 
> LGPL with a static linking exception will certainly address the
> technical issues.  From a non-technical perspective, BSD or MIT,
> would be more useful when getting Mercury accepted when creating
> proprietary software.
> 
> Most of what the LGPL with linking exception gives you over the say the
> BSD license isn't really particularly relevant for the runtime and large
> chunks of the standard library anyway because there isn't any meaningful
> way to modify them *without* modifying the compiler itself (and that
> will remain under the GPL).

It would be meaningful to take parts of the standard library as a starting
point for modifications. A linking exception to the LGPL will not exempt
an application (proprietary or otherwise) that uses the modified code
from any requirements of the LGPL. You could distribute the modified
source code under the terms of the LGPL and link to THAT, but, following
the OCaml example, you would need to distribute a modified version of
the Mercury system as a whole.

(Having said that, LGPL with linking exception would be acceptable to me
as long as we follow an existing example.)

Peter