Salesforce CEO Marc Benioff owns about 4% of the cloud computing software firm he cofounded in 1999. Before Salesforce, he spent 13 years at database software giant Oracle as a protege of Larry Ellison. Salesforce was a pioneer in hosting its software online, rather than installing it in clients' computer systems. He's an angel investor in dozens of tech startups and a prolific philanthropist. Benioff and his wife Lynne have pledged $350 million to University of California, San Francisco, for its children's hospitals and research.