Microsoft's founder, Bill Gates, has topped the Forbes rich list again with an estimated net fortune of $50bn (£29bn), celebrating his twelfth consecutive year as the world's richest man.
Microsoft co-founder Paul Allen was at number six with $22bn, according to Forbes, while Steve Ballmer, Microsoft's chief executive, had an estimated $13.6bn, putting him at number 24 on the list.
Two of the top five people in the Forbes Rich List 2006 were from the technology or communications industries, with Gates at number one and telecommunications giant Carlos Slim Helú at number three with $30bn (£17bn).
Investment guru Warren Buffett, flat-pack furniture pioneer Ingvar Kamprad and steel magnate Lakshmi Mittal completed the top five.
Michael Dell, founder of hardware firm Dell, was this year's number 12, with a fortune of $17.1bn, while Oracle's chief executive, Larry Ellison, dropped from number 9 to 15, and was worth $16bn.
Google founders Sergey Brin and Larry Page were ranked 26th and 27th respectively. Brin is worth $12.9bn, and Page $12.8bn.