[2/4] zeromq: add license information

From: Simon Dawson <spdawson@gmail.com>

Signed-off-by: Simon Dawson <spdawson@gmail.com>
---
 package/zeromq/zeromq.mk |    2 ++
 1 file changed, 2 insertions(+)

Le Sun, 19 Aug 2012 21:08:42 +0100,
spdawson@gmail.com a écrit :

> +ZEROMQ_LICENSE = GPLv3+
> +ZEROMQ_LICENSE_FILES = COPYING

No. Most of ZeroMQ is apparently under the LGPLv3+, but the
COPYING.LESSER contains a special exception. This needs to be encoded
differently.

Best regards,

Thomas

On 21 August 2012 11:42, Thomas Petazzoni
<thomas.petazzoni@free-electrons.com> wrote:
> Le Sun, 19 Aug 2012 21:08:42 +0100,
> spdawson@gmail.com a écrit :
>
>> +ZEROMQ_LICENSE = GPLv3+
>> +ZEROMQ_LICENSE_FILES = COPYING
>
> No. Most of ZeroMQ is apparently under the LGPLv3+, but the
> COPYING.LESSER contains a special exception. This needs to be encoded
> differently.

Okay; thanks Thomas. It's not clear to me how properly to express that
using the package license variables; I'll wait to see if there are any
suggestions.

Simon.

Simon Dawson wrote:
> On 21 August 2012 11:42, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
>> Le Sun, 19 Aug 2012 21:08:42 +0100,
>> spdawson@gmail.com a écrit :
>>
>>> +ZEROMQ_LICENSE = GPLv3+
>>> +ZEROMQ_LICENSE_FILES = COPYING
>>
>> No. Most of ZeroMQ is apparently under the LGPLv3+, but the
>> COPYING.LESSER contains a special exception. This needs to be encoded
>> differently.
>
> Okay; thanks Thomas. It's not clear to me how properly to express that
> using the package license variables; I'll wait to see if there are any
> suggestions.

ZeroMQ COPYING.LESSER defines the project license in a quite complex way:
a GPLv3+ with exceptions, plus some parts licensed under the MIT (X11)
license:

 > Parts of the software are licensed under the MIT (X11) license as 
follows:
 >
 > Copyright (c) 2007-2010 Contributors as listed in AUTHORS
 >
 >  Permission is hereby granted, free of charge, to any person
 >  obtaining a copy of this software and associated documentation
...
(From COPYING.LESSER, bottom part)

However, their Wiki has a clarifying page:
http://www.zeromq.org/blog:rfc-0mq-contributions

Briefly:
  - ZeroMQ used to be "open source" (license not reported) with comtributor
    agreement;
  - then they started accepting contributions under the MIT/X11 license;
  - in august 2010 they chose to switch to LGPLv3+, and converted all file
    headers accordingly.

So, it looks like the license is an "LGPLv3+ with exceptions", and the
"Parts under the MIT/X11" do not exist anymore. But I'm not sure my
understanding is correct.

It may be worth asking if the MIT/X11 part of COPYING.LESSER can be
considerednot applicable anymore, and so if it can be dropped to simplify
their license.

Of course searching their mail archives for more such info, or other
clarification, is the best thing. The period around august 2010 may be
interesting.

Simon, would you mind doing this research?

Luca

Hi Luca; thanks for looking into this.

On 24 August 2012 15:48, Luca Ceresoli <luca@lucaceresoli.net> wrote:
> So, it looks like the license is an "LGPLv3+ with exceptions", and the
> "Parts under the MIT/X11" do not exist anymore. But I'm not sure my
> understanding is correct.
>
> It may be worth asking if the MIT/X11 part of COPYING.LESSER can be
> considerednot applicable anymore, and so if it can be dropped to simplify
> their license.
>
> Of course searching their mail archives for more such info, or other
> clarification, is the best thing. The period around august 2010 may be
> interesting.
>
> Simon, would you mind doing this research?

I have spent some time searching the 0MQ mailing list, but have drawn
a blank. I have now posted a message on the mailing list, requesting
clarification of the license terms. (I agree that the MIT/X11 clause
appears to be superfluous.)

I'll let you know if and when I get a response.

Simon.

There has now been a response to my request on the 0MQ mailing list:

On 28 August 2012 12:38, Pieter Hintjens <ph@imatix.com> wrote:
> Indeed, this was the old JSON parsing library we used years ago for
> device configuration.
>
> Thanks for catching this. I'll fix the license.

So, as Luca suggested, the MIT/X11 license clause in COPYING.LESSER is
no longer required.

Consequently (and, again, as suggested by Luca), the license for the
Buildroot zeromq package would appear to be "LGPLv3+ with exceptions".

I'll fix my patch, and resubmit.

Simon.