Re: [exim] dlfunc and license issues

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Author: Nigel Metheringham
Date:  
To: exim-users
Subject: Re: [exim] dlfunc and license issues

On 17 Jul 2007, at 09:27, Philip Hazel wrote:

> On Mon, 16 Jul 2007, Claudiu Dragalina-Paraipan wrote:
>
>> I am developing a commercial content filtering software, and I am
>> considering the use of dlfunc feature to integrate it with Exim.
>> I would like to know if, in this case, the library used by dlfunc
>> will
>> have to be GPL too.
>
> Not only am I not a lawyer, but I have little knowledge of licence
> nitty-gritty. However, I believe that if you do not modify Exim and
> you
> do not distribute a modified Exim, something that you make to be used
> by, with, or from Exim can be licenced any way you like. After all,
> Exim
> has a "${run" facility, and nobody expects the things that it can
> run to
> be influenced by Exim's licence. As far as I can see, dlfunc is a
> similar case.


I'd feel that as something that is linked into the binary you would
be in a real grey area. You would be *much* safer if you separated
the differently licensed units and communicated over a socket or
shmem or similar. You may have to write an exim side shim to handle
this, and that would be best under GPL, but it can just be a shim and
you can keep the proprietary magic on the other side of the divide.

Now it may be a case that you would get away with just using a DL
component, but you might not, and even if you won a legal case with
it, there is sufficient ambiguity for it to cost you a substantial
amount to make your point :-)

However, in all licensing issues, lawyers and courts are the final
arbiters, and anything you get told on the internet is not a good
substitute.

    Nigel.
--
[ Nigel Metheringham           Nigel.Metheringham@??? ]
[ - Comments in this message are my own and not ITO opinion/policy - ]