Bill Gates has created the world's largest company, he is the world's richest man and he has become the biggest charitable giver in history.
He may be a college drop-out and "computer geek" but rivals have often underestimated his abilities in the cut throat world of business.
Despite the wealth and ruthless domination of the global computer industry, Gates maintains it is the programming itself which is his abiding passion.
He stood down as chief executive of Microsoft in 2000, to focus on software development and the new challenges of the mobile internet age.
The one-time high school computer enthusiast - whose worth passed the $100bn mark in 1999 - said he wanted to immerse himself again in the work he loves most.