The last bad boy of Silicon Valley’s original celebrity executives is retiring. Larry Ellison announced Thursday he’s stepping down as CEO of Oracle Corp., which he founded in 1977 and made him a multi-billionaire. Ellison, 70, said he’s leaving as a normal part of the company’s succession plan. Oracle hardware and software is integral to many companies and organizations’ retail, financial, and manufacturing systems. Ellison’s fortune has been estimated at $51.3 billion, making him the third richest man in the United States. With that money, he’s sponsored teams at the America’s Cup, and bought up swaths of Malibu, as well as the Hawaiian island of Lanai.