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

[Mark Brown]

On Mon, May 28, 2018 at 12:25 PM, Peter Wang <novalazy at gmail.com> wrote:
> (Having said that, LGPL with linking exception would be acceptable to me
> as long as we follow an existing example.)

Would you be happy with a pastiche of existing examples? On the face
of it, the ocaml license seems to grant permission to link to someone
else's modified version of the library. But I don't see how a license
can work that way. I believe the last two sentences of the classpath
license, on the other hand, would achieve the desired effect
(classpath is GPL, not LGPL, but that's not relevant to this point).

Below is text from ocaml, with the following changes:
- it's about the Mercury Core Libraries (is that what we call them?)
- LGPLv2, not v2.1 ("Library" not "Lesser")
- you can link with *this* version (i.e., the version of Mercury that
includes this exception), not with any public distribution
- you can include the exception in modified versions of the library,
if you choose

Are there any objections to making this change? Any other suggestions?

Mark

diff --git a/COPYING.LIB b/COPYING.LIB
index eb685a5..9ef923d 100644
--- a/COPYING.LIB
+++ b/COPYING.LIB
@@ -1,3 +1,25 @@
+In the following, "the Mercury Core Libraries" refers to all source
+code in the library, runtime, trace, browser and mdbcomp directories
+in this distribution.
+
+The Mercury Core Libraries are distributed under the terms of the
+GNU Library General Public License (LGPL) version 2 (included below).
+
+As a special exception to the GNU Library General Public License, you
+may link, statically or dynamically, a "work that uses the Mercury
+Core Libraries" with the Mercury Core Libraries to produce an
+executable file containing portions of the Mercury Core Libraries,
+and distribute that executable file under terms of your choice,
+without any of the additional requirements listed in clause 6 of the
+GNU Library General Public License. This exception does not however
+invalidate any other reasons why the executable file might be covered
+by the GNU Library General Public License. If you modify the Mercury
+Core Libraries, you may extend this exception to your version, but you
+are not obligated to do so. If you do not wish to do so, delete this
+exception statement from your version.
+
+----------------------------------------------------------------------
+
                  GNU LIBRARY GENERAL PUBLIC LICENSE
                       Version 2, June 1991