After bit more research total 98 Official GNU packages found to be
inactive for at least 5 years.
[...]
https://directory.fsf.org/wiki/ferret
Ferret works well and it is indeed used by at least 60 Debian users, as
seen in qa.debian.org's popcon.
It is also used by at least one university to teach conceptual datamodel
design.
Definitely not to be decomissioned.
