[tz] [PROPOSED] New edition of Calendrical Calculations

John Layt jlayt at kde.org
Tue Apr 3 19:39:41 UTC 2018

On 3 April 2018 at 19:50, Brian Inglis <Brian.Inglis at systematicsw.ab.ca> wrote:
> I doubt any issues with ports, as long as you don't publish the original Lisp,
> which is pretty straightforward code (except for the need to express formulae as
> Lisp expressions), or the output from the Lisp.
> Many of the formulae are obvious, published in their own earlier or others'
> works, or other public calendar software e.g. tzcode.
> Uses of non-creative non-original common public factual data and mathematical
> formulae (essential to all uses of calendars), including information from
> reverse engineering, appear to be unrestricted, from what I gather (IANAL).
> Why do you have a concern regarding taint?

Mainly because I've contributed code to a dual-licensed GPL/commercial
library that cannot accept code with non-commercial restrictions, but
also due to past statements they've made and their own commercial
licensing of the code and algorithms. I have no wish to become a test
case in the remote and expensive American legal system :-)

I fully agree that legally speaking their work probably is effectively
public domain and free for use (or at least should be, your legal
system may vary). As much as I disagree with their approach, I respect
their wish to not share their work, it just means I've had to rely on
more primary sources and my own deductions.


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