Wil O'Mullane I have made the changes to BSD. I think though that I should make a similar change to the obs_lsst package in the python/lsst/obs/lsst/translators sub directory so that we retain the option of moving that code out of there and into astro_metadata_translator. It will be easier to do that if the license of the subdir is compatible from the beginning (and it's compatible with GPLv3 in obs_lsst if we do this). I can make the change on this ticket as well if you would like. Kian-Tat Lim may also have an opinion.

Seems to me that it is complex to have a single package with multiple licenses for different directories within it. The number of authors does not seem so high as to prevent getting their approval to relicense if you move the code. Or just go ahead and move the code now.

Two reasons for not moving the code out of obs_lsst now:

1. It's changing a lot and I get the feeling that people will be grumpy if they have to make changes in obs_lsst and astro_metadata_translator.
2. Currently the detector name to detector number mapping requires the camera policy files in obs_lsst. I'm not sure whether it's okay to extract that mapping and keep it separate (or else have astro_metadata_translator try to load obs_lsst if it gets used: which will be a little against the ethos of making it easy for people outside the project to do the translations).

Presumably you need the approval of copyright holders, rather than authors, to relicense. Those will presumably be the DM institutions, and it seems unlikely to be a major hurdle (Princeton & UW won't care about licensing; I suppose maybe somewhere like SLAC might have institutional policies).

Tangentially, I note that the code in python/lsst/obs/lsst/translators refers me to “the COPYRIGHT file at the top-level directory of this distribution”, which doesn't seem to exist in obs_lsst. Kian-Tat Lim, as I recall you had a script that generated this file automatically — care to do the honours here?

The files in that directory were copied from templates in astro_metadata_translator rather than coming from obs_lsst. Most of the code was written by me anyhow (with a bit copied from pre-existing translations from Robert and Merlin). There is no UW code involved.

There is no UW code involved.

Yes, of course — I'm considering a potential future scenario where you want to relicense and the number of contributors has grown. I assume you already have permission to relicense your own work from your employer.

Right. The permission is effectively the same permission that Wil O'Mullane will be giving to astro_metadata_translator in this ticket when he reviews it.

When I look at your branch in githib https://github.com/lsst/astro_metadata_translator/blob/tickets/DM-17375/LICENSE   github still things its GPL .. which i guess it us until this ticket closes.   Otherwise looks good.

If you think we need to also do this in other packages and its not in conflict then please go ahead.

Much to my surprise, as soon as I merged GitHub changed the license banner to BSD.

and on the branch as well so the banner must come from master always I suppose.

Wil O'Mullane as we discussed on Wednesday I've also updated the license files in obs_lsst: I have stated BSD for translators and added the GPL and COPYRIGHT file to the root to meet the current standard. Can you or Kian-Tat Lim please take a look at the obs_lsst pull request?

Merged. Thank you Kian-Tat Lim and Wil O'Mullane for your reviews.