45. DAVID DUFFIELD

$10.7

BILLION  SELF-MADE SCORE: * SOURCE: BUSINESS SOFTWARE AGE: 79 RESIDENCE: INCLINE VILLAGE, NV PHILANTHROPY SCORE: Duffield’s first job as a systems engineer at IBM after college made a lasting impression. He founded three fairly successful software companies, the first at age 28, but left all three due to bureaucracy or infighting. At his fourth, PeopleSoft, he created a corporate culture modeled after the one at IBM. Oracle bought PeopleSoft in 2005. He then started enterprise software company Workday.