[AstroPy] POLL: vision for a common Astronomy package

Tom Aldcroft aldcroft at head.cfa.harvard.edu
Wed Jul 6 14:45:16 EDT 2011

On Wed, Jul 6, 2011 at 2:22 PM, Perry Greenfield <perry at stsci.edu> wrote:
> On Jul 6, 2011, at 7:06 AM, Tom Aldcroft wrote:
>> On Wed, Jul 6, 2011 at 4:56 AM, Erik Tollerud <erik.tollerud at gmail.com>
>> wrote:
>>> I suspect the most challenging part of the SOFA license is this
>>> clause: "The source code of your derived work must contain
>>> descriptions of how the derived work is based upon, contains and/or
>>> differs from the original SOFA software."  This implies that all work
>>> derived from it needs to describe explicitly how SOFA is used/altered.
>>> I suspect that's incompatible with most other open source licenses
>>> (although I'm certainly no lawyer, and for that matter I don't know if
>>> the SOFA board or IAU pay attention to this too closely).
>> This publication clause seems a little worrying here because (as I
>> believe Mark alluded) there needs to be way for users of astropy to
>> know they they used the SOFA library:   "In any published work or
>> commercial products which includes results achieved by using the SOFA
>> software, you shall acknowledge that the SOFA software was used in
>> obtaining those results."  Of course this is a somewhat theoretical
>> matter, in reality astronomers rarely acknowledge the software they
>> used and nobody is going to sue them for this.
>> I don't believe the intent of the SOFA license is that every code that
>> calls unaltered SOFA becomes tainted with the SOFA license, but rather
>> to make sure that no user distributes C/Fortran routines that *look*
>> like official SOFA-endorsed algorithms but are actually altered.
> IANAL, but when it says:
> 3. You (the user) may copy and distribute SOFA source code to others, and
> use and adapt its code and algorithms in your own software, on a world-wide,
> royalty-free basis. That portion of your distribution that does not consist
> of intact and unchanged copies of SOFA source code files is a "derived work"
> that must comply with the following requirements:
>        • Your work shall be marked or carry a statement that it (i) uses
> routines and computations derived by you from software provided by SOFA
> under license to you; and (ii) does not itself constitute software provided
> by and/or endorsed by SOFA.
>        • The source code of your derived work must contain descriptions of
> how the derived work is based upon, contains and/or differs from the
> original SOFA software.
>        • The name(s) of all routine(s) in your derived work shall not
> include the prefix "iau".
>        • The origin of the SOFA components of your derived work must not be
> misrepresented; you must not claim that you wrote the original software, nor
> file a patent application for SOFA software or algorithms embedded in the
> SOFA software.
>        • These requirements must be reproduced intact in any source
> distribution and shall apply to anyone to whom you have granted a further
> right to modify the source code of your derived work.
> *******
> The phrase '"derived work" that must comply with the following requirements'
> sure seems to applying new terms to the original license of the derived
> work. It's not clear that the SOFA license is GPL-compatible for example
> (the requirement on usage--i.e., publishing data using it requiring
> acknowledgement,  or the iau prefix restriction for example).
> Perry

Earlier today I sent a message to the contact email for the IAU SOFA
tools asking them to look over this discussion thread and weigh in
with their interpretation of their license agreement.  Can't hurt to
ask, and if it turns out they really intend this restrictive and viral
license then it's everyone's loss.

- Tom

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