Facebook's Zuckerberg vows to donate his wealth

Mark Zuckerberg, the billionaire behind Facebook, has pledged to part with a sizable chunk of his fortune for good causes.

Zuckerberg and 15 other billionaires signed on to the Giving Pledge, agreeing to donate the majority of their fortunes to charity. With the new names added to the list of charitable donors today, there now are 50 signatures, including AOL co-founder Steve Case, Microsoft co-founder Paul Allen and Larry Ellison, co-founder and CEO of Oracle.

Zuckerberg isn't the only one at Facebook to make the pledge. Dustin Moskovitz, who co-founded Facebook along with Zuckerberg, also took the pledge.

"People wait until late in their career to give back," Zuckerberg said in a statement. "But why wait when there is so much to be done? With a generation of younger folks who have thrived on the success of their companies, there is a big opportunity for many of us to give back earlier in our lifetime and see the impact of our philanthropic efforts."

The Giving Pledge, an effort organized by Bill Gates, asks the wealthiest individuals and families in the U.S. to commit to giving the majority of their wealth to the charitable organizations of their choice either during their lifetime or after their death.

This isn't Zuckerberg's first major charitable donation.

This past September, Zuckerberg announced the creation of a new foundation called Startup: Education . He also seeded the organization with an "initial gift" of $100 million earmarked for the Newark, N.J., school system.