Color me impressed. And jealous. But mostly impressed. Go, John, go!
Little Fuzzy itself is in the public domain, but its sequels are still under copyright. While it might have been technically possible to write Fuzzy Nation without the permission of the Piper estate, because of the status of the sequels there were enough (forgive the pun) fuzzy legal areas that I didn't want to have to deal with them. Beyond this, because Fuzzy Nation is in many ways meant to be a tribute to Little Fuzzy and to Piper himself, I wanted the blessing, so to speak, of the Piper estate.The Super Secret Thing That I Cannot Tell You About, Revealed: Introducing Fuzzy Nation
So, after I wrote Fuzzy Nation, my super-invaluable and incredibly awesome agent Ethan Ellenberg approached the rights holders to the Piper estate and started talking to them about it. The discussions took, well, a long time. But we reached agreement on it, and I'm happy to say Fuzzy Nation is an authorized work.