MacKenzie Bezos joined some of the world's wealthiest people in a pledge to give away at least half of their wealth to charitable causes.

The Giving Pledge, which was started by Warren Buffett and Bill and Melinda Gates in 2010, announced Bezos' commitment Tuesday. Billionaire hedge fund manager Paul Tudor Jones also announced on Tuesday that he and his wife have signed it. His wealth is estimated by Forbes at more than $5 billion.

Bezos became one of the world's wealthiest women following her divorce from Amazon CEO Jeff Bezos, who has yet to sign the Giving Pledge himself, although he praised her move as "amazing and thoughtful."

While MacKenzie Bezos said she left Jeff Bezos with 75% of their Amazon stock as well as all of their interests in The Washington Post and Blue Origin space venture, she still has a net worth of $36.6 billion and ranks No. 22 on Bloomberg's Billionaires Index. Her ex-husband, according to the index, is the wealthiest man in the world with a net worth of $114 billion.

"We each come by the gifts we have to offer by an infinite series of influences and lucky breaks we can never fully understand. In addition to whatever assets life has nurtured in me, I have a disproportionate amount of money to share," MacKenzie Bezos wrote in her letter announcing her commitment to the pledge. "My approach to philanthropy will continue to be thoughtful. It will take time and effort and care. But I won't wait. And I will keep at it until the safe is empty."

Jeff Bezos applauded his ex-wife's pledge in a tweet on Tuesday.

"MacKenzie is going to be amazing and thoughtful and effective at philanthropy, and I'm proud of her. Her letter is so beautiful. Go get 'em MacKenzie," he wrote.

MacKenzie Bezos is now part of a group of 204 people from 23 countries who have signed the pledge to give away half of their wealth during their lives or at the time of their death. Joining her are some other familiar names in the tech industry. Brian Acton, one of the WhatsApp co-founders who sold the messaging platform to Facebook in 2014, also signed the pledge. Acton is now worth more than $4 billion, according to Bloomberg's Billionaires Index. Coinbase CEO Brian Armstrong, whose net worth tops $1 billion, according to Forbes, also joined the pledge.

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Watch: MacKenzie Bezos pledges to donate most of her wealth to charity