MacKenzie Bezos, the world’s third-richest woman following her divorce from Amazon founder and CEO Jeff Bezos, has signed the Giving Pledge — a commitment that will see her giving away more than half her wealth to philanthropy or charitable causes, either during her lifetime or in her will.

Bezos recently made headlines when she gave ex-husband Jeff 75% of their joint Amazon stock, and voting control, in their divorce, along with their interests in The Washington Post and Blue Origin. However, that still left her with an at least $35.6 billion stake in Amazon. Bloomberg’s Billionaires Index now estimates her net worth at $36.6 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,” wrote MacKenzie Bezos, in a letter published by the Giving Pledge today, announcing her intention to give away her wealth.

“In addition to whatever assets life has nurtured in me, I have a disproportionate amount of money to share. 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,” she said.

Ex-husband Jeff Bezos tweeted praise for MacKenzie’s pledge this morning:

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. https://t.co/S2gLLBQyRQ — Jeff Bezos (@JeffBezos) May 28, 2019

Jeff Bezos, now the world’s richest person ahead of both Bill Gates and Warren Buffett, has not signed the Giving Pledge himself.

Founded in 2010 by Bill and Melinda Gates and Warren Buffett, the Giving Pledge encourages the world’s richest people to give away more than half their wealth. Other notable names who have previously signed the pledge include Mark Zuckerberg and Priscilla Chan, Elon Musk, Richard Branson, Larry Ellison, Michael R. Bloomberg, Pierre Omidyar and many more.

Today, the program announced 19 more philanthropists have signed their names to the pledge, bringing the total number of signatories to 204.

In addition to Bezos, other tech industry additions announced today include: Tegan and Brian Acton — the latter who co-founded WhatsApp, the messaging app bought by Facebook in 2014 for $19 billion; Coinbase co-founder and CEO Brian Armstrong; co-founder of bitcoin trading platform BitMEX Ben Delo; Twilio CEO Jeff Lawson and Erica Lawson; Lowercase Capital partners Chris and Crystal Sacca; and Pinterest co-founder Paul Sciarra and Jennifer Sciarra.

Globally, there are now signatories from 23 countries: Australia, Brazil, Canada, China, Cyprus, Germany, India, Indonesia, Israel, Malaysia, Monaco, Norway, Russia, Saudi Arabia, Slovenia, South Africa, Switzerland, Tanzania, Turkey, Ukraine, United Arab Emirates, the United Kingdom and the United States. In the U.S., the largest contingents are from New York and California.

Bezos’ full letter detailing her plans is below: