Back in 2010, Bill Gates and Warren Buffett started something called The Giving Pledge, where they promised to give away most of their money to charity throughout their lives. According to Business Insider, 14 more billionaires just signed on.

None of them are all that famous, so if you're like me, you might not know their names. But I'll bet you know their companies. One of them is Dagmar Dolby. She’s the widow of the guy who created Dolby surround sound. Nick Hanauer was an early investor in Amazon. And Harry Stine owns Stine Seed, the largest seed company in the U.S.

Some of the more famous billionaires have already signed the pledge, including          Mark Zuckerberg, George Lucas, and Michael Bloomberg. All in all…168 people in 21 different countries have now signed it, and almost all of them are billionaires.          Together, they've promised to give almost $400 BILLION to charity.