Would it be possible to start into that by creating prefixes for the
different package repositories?
(akkuscm ...) and (snow-fort ...)
I advise against doing that, as the same package can be published to
multiple repositories.
(how do I find out whether they are portable? Do I have to try?)
Last I checked, you just have to try.
(how do I find the license? In snow-fort I don’t see any license info,
in akkuscm I see NOASSERTION for (slib minimize) but it should be BSD-3
or public domain)
IIRC in Snow packages the license is declared manually in package.scm
files, whereas Akku reads SPDX data from the source tree.
Though I see that for example (pfds ...) and (slib ...) are in both. And
akkuscm seems to import snow-fort.
Indeed, that is correct.