[Joe Ross]

I don't see anywhere that the code is explicitly licensed to us, nor
is it explicitly copyrighted (although the code on kevin.org is
explicitly copyrighted, due to the notice at the bottom of his page).
Thus the code has an implicit copyright, and you need to ask
permission to republish it, like in your library.

Something isn't in the public domain unless it is explicitly put in
the public domain by the creator.