Steve Ballmer vs. Elon Musk

Ballmer and Microsoft cofounder Bill Gates were classmates at Harvard. Ballmer created a website called USAFacts.org for people to look up and understand where the government is spending money.

Musk, who says he's worried about population collapse, has nine children with three women, including triplets and two sets of twins. As a kid in South Africa, Musk taught himself to code; he sold his first game, Blastar, for about $500.