[Asterisk-Dev] voicemail message number limits

[Craig Southeren]

On Sat, 24 Jul 2004 18:08:30 -0700
dking at pimpsoft.com wrote:

> If that is the case then since you signed away any rights you have to your work/source when you joined the effort, then they have the full ability to legally take asterisk out of gpl at will.

This statement is a mixture of truth and untruth. 

No-one can "sign away any rights you have" because the GPL guarantees
you have rights even outside of copyright. 

However, it is true that Digium could legally take Asterisk out of GPL
at will. I've included an explanation below as to why that is a
side-effect of the actual intent, and why it is not such a big deal
in any case.
 
> The thing is, that would also be illegal, so by reference what your saying is either not true/valid or proves my point above.

This statements is simply wrong. It's not not illegal, immoral, or even
bad. :)

To understand why, you need to distinguish between copyright and license.
As someone who has been involved in Open Source telephony for over 6
years, and has given numerous public talks on the topic, I think I can
speak with some degree of knowledge on this issue. Apologies in advance
for the length of this post, but it's a complicated issue!

The GPL is a license. A license controls who may use the code and the
conditions under which that usage may occur. It says nothing about
copyright, because that is a totally different topic. If you don't
believe me, read the GPL yourself and the associated FAQ. The closest
the GPL comes to referencing copyright is here: 

http://www.gnu.org/licenses/gpl-faq.html#RequiredToClaimCopyright

Asterisk is distributed under what is essentially a standard GPL with
certain extensions to allow linking with non-GPL software such as
proprietary codecs. As pointed out by previous posters, this is almost
mandatory for any GPL telephony software (see GnomeMeeting and GnuGK as
other examples) due to the proliferation of proprietary standard within
the industry. Without that, Asterisk would be unable to interoperate in
any useful way with existing equipment.

Because Asterisk is covered by the GPL, everyone has the same rights as
far as *usage* of the Asterisk code in concerned. The software can be
used by anyone, forked by anyone, and distributed by anyone under the
terms of the GPL. In this sense, you may consider the code at Digium to
be just one fork of the Asterisk code that Mark and the folks at Digium
have decided to maintain. Anyone can create their own code fork at any
time, but it says a lot for the abilities of Digium that no-one has
chosen to do so to date.

Now, lets talk about copyrught.

Mark has chosen to require that the copyright for all contributions to his
version of Asterisk must be assigned to Digium. Saying that this violates
the GPL, or that it is "illegal" is a stupid statement - because the GPL
places no restrictions on copyright. That's like saying that the GPL is
violated by a project that requires all contributions to be written in
English, or by a project requires all contrbutions to be submitted by
email. There is no GPL violation because the GPL does not cover these
topics.

Mark has publically stated that the reason for requiring all
contributors to his version of Asterisk to assign copyright to Digium is
to allow the license to be changed by Digium. Whether you believe him or
not, this is a very good reason. Consider that when Netscape changed the
license for Mozilla from MPL to GPL, they were forced to contact every
single person and company that had ever contribnuted to the code and get
written permission from them to change the license. This was a massive
effort and is something that would not be feasible for a company the
size of Digium.

The result of this is that Digium can alter the license for their
version of Asterisk to allow the incorporation of new codecs or
libraries without having to contact hundreds of people every time it
needs to happen. I can't see how anyone could think this is a bad thing.

As a side effect, it is true that this copyright assignment also means
that Digium could decide to fork the Asterisk project and take it
completely closed source, or license it to Microsoft, or do anyone of a
hundred other unlikely things. But even if they did, the currently
existing versions of the Asterisk code would continue to be available
under the existing GPL license. Anyone could pick up the current code,
start a new SourceForge project and announce Asterisk II. In fact, they
could do that right now if they really want to.

Lastly, even had Mark not had the foresight to make copyright
assignmment a prerequisite for contribution to the Digium fork of
Asterisk, then he could could still "do a Netscape" and relicense all of
the Asterisk code that he wrote and hence has copyright for. Given that
this would probably be most of the code in Asterisk, it's hard for
someone with an understanding of the facts to read anything into the
copyright assignment other than it is a good idea to reduce the ongoing
effort involved in integrating with proprietary software that would
otherwise be impossible with an unmodified GPL.

I hope this clarifies a difficult and complicated topic.

   Craig


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