Re: Gtkmm, LGPL and C++

[Chris Vine <chris cvine freeserve co uk>]

On Wednesday 21 February 2007 11:05, Neil wrote:
> Chris, Jonner
>
> Thanks for the pointers - and confirmation of what Gtkmm intends.
>
> My issue is with templates rather than sub-classing. There's a fair bit
> on the latter that I also found that suggests sub-classing needn't be an
> issue.

If it is important to you or your business, then you need to consult an 
intellectual property lawyer.  Having read the LGPL, I personally would not 
release important proprietary code based on a templated library licenced 
under it, such as libsigc++ (which is where the problem, if there is one, 
mainly resides with gtkmm), but I imagine that there are those who take a 
different view, such as Jonathon.

You have the assertion of one of contributors to libsigc++ that the intention 
is clear, so he at any rate would presumably not pursue you.  The problem 
with amending the licence is that it requires the consent of everyone who 
owns copyright to the code concerned (that is, the authors).  If there are 
more than two or three contributors that can become difficult.  Any person 
who has the copyright to code within any particular library in question could 
in theory assert the terms of the licence under which they make it available, 
whatever view other copyright holders may take.

I do not believe that subclassing is a problem under the LGPL if it only 
involves linking with the code being sub-classed, but the LGPL is quite 
opaque and as I say, if it is important to you then take legal advice.

Chris