Back in the day, computers had no build-in reliable way of generating entropy data (random numbers). These programs filled that gap by producing (aed, ved, te) and distributing (entropybroker) those numbers.
aed - produce entropy from audio (from an alsa device)
ved - produce entropy from video (from a video4linux device)
te - produce entropy by comparing timers
entropybroker - distribute (securily) entropy data from and to systems