OpenAI CEO Sam Altman has pledged to donate the majority of his wealth, joining other billionaires contributing hundreds of millions of dollars to philanthropic causes.

In a letter posted to the Giving Pledge earlier this month, the 39-year-old entrepreneur and his husband, Oliver Mulherin, said the money will be dedicated to supporting technology that "helps create abundance for people."

"We would not be making this pledge if it weren’t for the hard work, brilliance, generosity, and dedication to improve the world of many people that built the scaffolding of society that let us get here," the letter reads. "There is nothing we can do except feel immense gratitude and commit to pay it forward, and do what we can to build the scaffolding up a little higher."

Altman's net worth is at least $2 billion no thanks to OpenAI but rather several startup investments, Bloomberg reported in March. He has invested in Fusion power company Helion Energy, which Microsoft agreed to a nuclear power purchase deal last year, and Retro Biosciences, the Biotech company working to increase the average human lifespan by another 10 years, according to Forbes. He has also invested over $60 million in Reddit since 2014.

The 38-year-old's donation promise comes after he was removed and quickly reinstated as CEO of the San Francisco-based company responsible for AI software ChatGPT. Altman co-founded the company as a research lab in 2015 and became CEO in 2019.

Pledge is not legally binding

Like all Giving Pledge vows, the moral commitment is not legally binding. It's unclear how much money Altman and Mulherin will be donating and which organizations it will go to.

The charitable campaign, founded in 2010 by Warren Buffett and former couple Bill and Melinda French Gates, aims to encourage the world's elite to offer at least half their fortunes to charities and other philanthropic causes.

Pledgers are expected to donate within their lifetimes or in their wills. Over 245 wealthy couples or individuals have made the pledge spanning 30 countries.

"The Giving Pledge aims over time to help shift the social norms of philanthropy among the world’s wealthiest and inspire people to give more, establish their giving plans sooner, and give in smarter ways," the campaign said on its website.