He was Microsoft's 30th employee, its first business manager and CEO for over a decade. Now, after 34 years with the company, Steve Ballmer is leaving Microsoft behind. In a letter to Satya Nadella, Microsoft's new CEO, Ballmer explained that he's leaving the company's board of directors effective immediately. "I have become very busy," he explains. "I see a combination of Clippers, civic contribution, teaching and study taking up a lot of time." It's not a surprising development -- owning an NBA franchise is a pretty big responsibility, after all -- but it marks the end of Ballmer's decades-long influence over the company. Despite his departure, the former-CEO is still invested in the company's success, and spent most of the letter encouraging Nadella and giving advice.