dbz(3) on Linux
The text 64b7cefbec7b, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo) shipped it.
somewhat dbm-compatible database routines dbzfresh, dbzagain, dbzfetch, dbzstore - database routines dbzsync, dbzsize, dbzincore, dbzcancel, dbzdebug - database routines