$130 Million Mansion, Tracks Residents.
Bill Gates is among those who have held the label "world's richest man" the longest.
His twelve-figure net worth was propelled by the digital behemoth Microsoft Corp.,
which the billionaire established. As one might expect from someone who founded one of the most ,
successful software companies in history, he constructed his own home from the ground up.
You are given a key when you enter the house that is preprogrammed ,
with your preferences for everything from lighting and music to room temperature.
The key keeps track of your movements, and as a safety precaution,
if you are on the floor and no key is found, you will activate the alarm system.