Hello,
As you may recall, I am (unofficially) maintaining the IRAF data
analysis package. IRAF includes NCAR from UCAR (.. Atmospheric
Research). It was previously decided [1] that the license from NCAR
was very much not DFSG-free.
However, the NCAR routines are now available under the GPL. I tried
to contact them earlier this year (before I knew it was GPL'd, and
possibly before it *was* GPL'd) and got no response. I've since
been in contact with an NCAR representative. I asked if they would
consider making a statement that version 1.00 of their code was
available under the GPL (as well as the latest version: 4.3.1).
Failing that, I have begun an audit of the NCAR code included in IRAF.
I can delete the tests/ directory, as it is unused. That leaves about
100 files. Half of those differ (v1.00 and v4.3.1) solely in the
copyright banner, and are, as such, effectively available under the
GPL.
As for the remaining files, I'm trying to classify the changes that
are made. My goal is to include an explanation of every change in
./debian/copyright.
Many of the changes are trivial:
+ a(b(c));
- a(c);
or:
+ a(b(c));
- a(d(c));
or something like adding a single (trivial) line of code:
+ fflush(a);
It is my understanding that if one understands the *algorithm* a piece
of code uses, then one is free to reimplement (and relicense) that
algorithm.
I think it is clear that the *intent* of NCAR is to make their code
GPL'd, and so I'm probably just being pedantic, but seems like a good
best practice.
Anyway, is this a reasonable course of action? If I explain each and
every change between the 1.00 version included in IRAF and the GPL
4.3.1 version, (in english), then it should be clear that I understand
what the changes *do*, functionally. And therefor I could implement
the equivalent changes to the GPL version to obtain a GPL version
equivalent to the IRAF version, but libre.
(This also depends on my having the legal right to view the NCAR 1.00
source included in IRAF, which I think was not an issue. Based on
replies to [1], the only issues were limits on redistribution).
I will then, of course, evaluate the changes, and see if v4.3.1 offers
any bugfixes over 1.00. If so, incorporate the changes in the Debian
package (as a separate patch .. gotta learn to do that) and send the
patches upstream, too.
Thanks,
--
Justin
References
[1] http://lists.debian.org/debian-legal/2004/05/msg00338.html
