Re: Simple GTKMM front-end

[Chris Vine <chris cvine freeserve co uk>]

On Tue, 20 Sep 2011 21:26:31 +0100
John Emmas <johne53 tiscali co uk> wrote:
> On 20 Sep 2011, at 07:11, Andy Tai wrote:
>
> > come on... gtkmm is LGPL...
>
> Interesting....  I just checked this on the gtkmm web site and
> discovered that it's actually released under the "GNU Library General
> Public License".  After further reading it seems that inclusion of
> the word "Library" indicates that this is an old version of what
> later morphed into the "Lesser General Public License" or "LGPL".
> Technically though, it's neither GPL nor LGPL in the modern sense.
> Clause 5 of the "Library" General Public License states:-
>
> " linking a "work that uses the Library" with the Library creates an
> executable that is a derivative of the Library"
>
> [...]
>
> " if the work is a derivative of the Library, you may distribute the
> object code for the work under the terms of Section 6. Any
> executables containing that work also fall under Section 6, whether
> or not they are linked directly with the Library itself. "
>
> However, sections 6 and 2 seem to state the you need only distribute
> the source code for any changes you made to the library.  For example
> if your executable uses classes derived from gtkmm, you must release
> those classes (and any modifications that were needed to gtkmm) as a
> new library in its own right.  However, those parts of the executable
> which make no use of gtkmm do not need to be released.
>
> So it's probably closer to the LGPL than to the GPL but you might
> still need to release parts of your source code.

As far as I am aware the only difference between the Library General
Public Licence v2, and the Lesser General Public Licence v2.1 is the
change of name.

gtkmm is released under the LGPL-2.0 or later, at the choice of the
user. That includes the LGPL-3.0, which would be the choice of any C++
developer because of the template exemption.

Chris