Posted: Fri Aug 11, 2000 5:28 am Post subject: [Asterisk] Askerisk and GPL, OpenH323 and MPL
To all,
Recent conversations on the issue of MPL vs GPL have caused me to re-examine
the issue of using OpenH323 in Asterisk.
I am starting to think that there is no problem with doing this - it just
requires a novel way of looking at the licensing issues.
The GPL simply requires that any code included with GPL code is redistributed
under the same conditions as the GPL. A quick scan of the GPL does not reveal
anything that would break the conditions of the MPL. You are not even required
to put headers in the files - the license merely advises that it is a good
idea. Hence, I can see no reason why a copy of the OpenH323 code could not be
distributed as part of a GPL bundle. This does not violate the MPL, and it does
not appear to violate the GPL.
Problems appears if changes are required to the OpenH323 code in order to
support the GPL code base. In this case, there are two options:
1) Changes could be made to OpenH323 under the MPL, and the resultant code
then used in the GPL code base.
2) GPL code could be written to interface to the OpenH323 code and kept as
GPL. This is allowed by the MPL.
Posted: Fri Aug 11, 2000 7:21 am Post subject: [Asterisk] Askerisk and GPL, OpenH323 and MPL
Craig,
I think this could work I've been reading the relavent licence files all
afternoon .. perhaps we should build a summary of this and try and get
an expert opinion.
If I understand correctly:
In binary/compiled form:
As required by the GPL and allowed by the MPL compiled code is
licenced under the GPL.
In source code form:
Open H323 code would be MPL'ed and distributed in it's own directory,
changes made to any of the existing source/header files would have to
remain MPL'ed. If required, Mark Spencer may be able to make exceptions
to allow some GPL code to be reused (specifically allowed under clause 10
of the GPL).
Asterisk is GPL'ed and will remain so. Where H323 code isn't being changed
new code remains GPL'ed.
The part that may be sticky comes from clause 2 of the GPL :
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
This could be interpreted to mean that IF all the source code was distributed
together then this could be considered as a 'whole' where the GPL requires
everything to be GPL'ed while the MPL specifically states source code must
be available under the MPL. This could possibly overcome by distributing the
MPL'ed portions separately (ensuring that the GPL'ed portions DO compile and
run on their own). Alternatively it could be interpreted that so long as
the Open H323 stuff remains in it's own directory and doesn't intermingle
with the GPL source code directly it doesn't become a whole until it's
compiled.
Rohan Tronson
On Fri, Aug 11, 2000 at 03:28:55PM +1000, Craig Southeren wrote:
Quote:
To all,
Recent conversations on the issue of MPL vs GPL have caused me to re-examine
the issue of using OpenH323 in Asterisk.
I am starting to think that there is no problem with doing this - it just
requires a novel way of looking at the licensing issues.
The GPL simply requires that any code included with GPL code is redistributed
under the same conditions as the GPL. A quick scan of the GPL does not reveal
anything that would break the conditions of the MPL. You are not even required
to put headers in the files - the license merely advises that it is a good
idea. Hence, I can see no reason why a copy of the OpenH323 code could not be
distributed as part of a GPL bundle. This does not violate the MPL, and it does
not appear to violate the GPL.
Problems appears if changes are required to the OpenH323 code in order to
support the GPL code base. In this case, there are two options:
1) Changes could be made to OpenH323 under the MPL, and the resultant code
then used in the GPL code base.
2) GPL code could be written to interface to the OpenH323 code and kept as
GPL. This is allowed by the MPL.
Posted: Fri Aug 11, 2000 1:25 pm Post subject: [Asterisk] Askerisk and GPL, OpenH323 and MPL
Quote:
The GPL simply requires that any code included with GPL code is
redistributed under the same conditions as the GPL. A quick scan of
the GPL does not reveal anything that would break the conditions of
the MPL. You are not even required to put headers in the files - the
license merely advises that it is a good idea. Hence, I can see no
reason why a copy of the OpenH323 code could not be distributed as
part of a GPL bundle. This does not violate the MPL, and it does not
appear to violate the GPL.
Section 2b says: "You must cause any work that you distribute or publish,
that in whole or in part contains or is derived from the Program or any
part thereof, to be licensed as a whole at no charge to all third parties
under the terms of THIS LICENSE." (with "this license" referring to the
GPL). It's not simply the same terms.
Craig, we've hashed over this before, and I think that there are some
serious technical issues associated with mixing Asterisk and OpenH323
together, since (I believe) both want to be the "main thread" of the
program. I imagine it will be much easier to use libiax to create an
OpenH323 channel.
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