Achievements: CEO of Oracle since 1977, Larry Ellison is best known as the man who began the relational database industry. While databases were not new to the tech industry, up to this point they were dependent on a team of programmers and mass amounts of time to be able to derive meaningful analytics from the complex algebraic formulas. Ellison won over clients by demonstrating on-the-spot queries that previously would have taken weeks to pull together.
Today: Ellison still helms Oracle as the company's CEO and is the sixth wealthiest person in the world with a net worth of $36.5 billion, according to Forbes. Ellison currently owns a stake in four diverse companies that range from software and biotechnology research to pharmaceuticals. Last month Ellison purchased Lanai, a Hawaiian island, for $500 million.