Bill Gates, born October 28, 1955 in Seattle (Washington State), is an American computer scientist and entrepreneur, a pioneer in the field of microcomputing. He founded in 1975, at the age of 20, with his friend Paul Allen, the micro-computer software company Micro-Soft (renamed from Microsoft). His company bought the QDOS operating system to make it MS-DOS, then designed the Windows operating system, both of them in a situation of virtual world monopoly.
Thanks to Microsoft's commercial success, he became the richest man in the world from 1996 to 2007, as well as in 2009, and from 2014 to 2016. When he again became the richest man in the world, according to the Bloomberg ranking, in January 2014, his fortune amounted to 78.5 billion US dollars
