The Overseer's terminal password is a holotape in Fallout 3.
Location
It can be obtained by killing or pickpocketing Alphonse Almodovar during Escape!, by telling him that Amata will be hurt if he doesn't hand over his key, or from a locker in the overseer's office. The password allows access to the overseer's computer in his office.
Transcript
The password is Amata.
