[Mimedefang] GPLv3

David F. Skoll dfs at roaringpenguin.com
Sat Jun 30 22:53:23 EDT 2007

Richard Laager wrote:

> First off, I'm not a lawyer. ;) This is not legal advice, only a summary
> of my understanding of all this.


> If you (Roaring Penguin) have accepted patches, you are not the sole
> copyright holder, unless you received a copyright assignment for every
> patch that's substantial enough to receive copyright protection (which
> is an issue I'm not qualified to talk about).

We have not accepted substantial patches.  The only patches we've
accepted have been minor bug fixes or additions for new virus scanners
that closely follow the basic pattern of our existing virus-scanning
code.  We also typically rework submitted patches for various reasons,
rather than accepting them verbatim.

> If MIMEDefang is GPLv2-only right now, then you can't change that
> without getting consent from every other copyright holders or replacing
> that code.

That's true.  If we make the change, I would expect anyone who claims
to hold copyright to part of MIMEDefang to speak up, but I'm unaware
of anyone who's in that position.


> Also, your note about service providers and distributing conflicts with
> the common interpretation of the GPL (Google for "GPL web services", for
> example), shared by the FSF [0].

Yes, I realize that.

> If you actually want to make and enforce that as a licensing
> condition, you probably want something like the AGPLv3 (when it's
> released, which should be soon, now that the GPLv3 is out) or an
> earlier version of the Affero GPL, though I don't know (as I haven't
> read it) if that's too specific for web stuff to be of use for a
> mail filtering application.

The existing AGPL is too web-specific to be of use for MIMEDefang.
GPLv3 is much more specific about forbidding additional restrictions
than GPLv2 was, which is one reason I am hesitant to change the



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