Re: [libxml++] Licensing

["Murray Cumming" <murrayc murrayc com>]

> Dear all,
>
> Recently a developper from a big company (I've been asked not to tell
> which one) contacted be about libxml++ license.
>
> Their legal deparment, to allow the use of a GPLed C++ library,

libxml++ is not GPLed. It is LGPLed, so the question seems to be
completely irrelevant. They can do whatever they want - this is maybe a
simpler explanation for them:
http://www.gtkmm.org/license.shtml

Here are some things that they can not do:
1. Link statically (instead of dynamically) to libxml++.
2. Change their own copy of libxml++ and distribute object code (for
instance, an application+DLLs that a user installs) for that changed
libxml++, but then refuse to give the changes to people who have received
the object code.

You might want to put a similar clarification on a page on the website,
and you might want to say that that, of course, C++ derivation is not
considered different to normal use of a C function. It's the first time
that I've heard of anybody being confused about that though.

> need the
> copyright owner to clarify a quite simple point, about deriving classes
> from libxml++.
> The clarification has been expressed like this :
>
> "FOR THE AVOIDANCE OF ANY DOUBT, DERIVING SUB-CLASSES BASED ON LIBXML++
> CLASSES IN A PROPRIETARY FILE DOES NOT MAKE SUCH PROPRIETARY FILE A WORK
> BASED ON LIBXML++, PROVIDED THAT SUCH PROPRIETARY FILE IS NOT ITSELF A
> LIBRARY"

1. If we were talking about the GPL then this would be a false statement,
because you can not derive from a C++ class without in some way linking to
the GPLed code.

2. For both, the GPL and LGPL, nobody care's whether your proprietary work
is a library or a standalone application - both would have to link to the
GPL/LGPLed code.

> My personnal opinion is that this point is ok, and if adding it to the
> license as a clarification allows more people to use libxml++, I'd like
> to do it.
>
> However before making any decision, I want to have some other points of
> view, especially if some of you disagree.

Murray Cumming
murrayc murrayc com
www.murrayc.com
www.openismus.com