Ballmer is roughly the tech industry’s equivalent of Mikhail Gorbachev, without the coup and the tanks and Red Square. When he took control, in 2000, Microsoft was one of the most powerful and feared companies in the world. It had a market capitalization of around five hundred billion dollars, the highest of any company on earth. Developers referred to it as an “evil empire.” As he leaves, it’s a sprawling shadow. It still has cash—but that matters little.