Marco della Cava

USA TODAY

SAN FRANCISCO — Tech titans are among the 17 new signatories to the Giving Pledge, an initiative started in 2010 by Bill Gates and Warren Buffett aimed at getting the world's billionaires to give away the bulk of their spoils.

Salesforce founder Marc Benioff and his wife Lynne as well as Airbnb co-founder Brian Chesky signed the pledge. That brings the total group, which ranges in age from 30 to 100, to 154 members in 16 countries. Gates announced the new additions Wednesday at the Code conference in Rancho Palos Verdes, Calif.

The Benioffs have been conspicuous donors here, most notably giving $200 million to expand the UCSF Benioff Children's Hospital. Benioff, 51, is worth $4 billion; his cloud computing company (CRM) has a market cap of $56 billion. Chesky, 34, who has not made as big a splash on the charitable front to date, is worth $3 billion; privately held Airbnb has been valued at $20 billion.

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Joining Chesky on the list are two other Airbnb co-founders, Joe Gebbia and Nathan Blecharczyk.

“We are humbled to find ourselves at a young age in an extremely privileged place," Blecharczyk said in a statement. "We recognize that the world has many real challenges and that we are in a unique position to have significant positive impact. We feel a responsibility to share our good fortune, and we pledge to dedicate the majority of our wealth over time to philanthropy.”

Other new pledge members include Saudi business titan Prince Alwaleed Bin Talal Bin Abdulaziz AlSaud, Intuit founder Scott Cook and his wife Signe Ostby, and Indian biotech entrepreneur Kiran Mazumdar-Shaw.

Gates, co-chair of the Bill & Melinda Gates Foundation, said in a statement that while "some (pledge members) have been giving for decades and others are just starting out after building successful businesses, they all see the value of giving in a bold and effective way. Melinda, Warren and I are glad to have the opportunity to learn with them and from them.”

Many Giving Pledge remembers recently gathered for the organization's annual two-day conference during which outside experts in philanthropy offered guidance on the best ways to deploy resources across a range of issues.

Among the issues discussed were how to leverage philanthropy to drive women’s opportunities in the global economy, create opportunities and overcome challenges for giving internationally, solve environmental issues, engage in urban renewal projects and advance scientific discovery.

Despite the staggering wealth of many Giving Pledge members, the Gates Foundation towers over them all with an estimated $44 billion in assets. Although the foundation deploys its resources worldwide, the Gates have put a particular emphasis on improving living conditions for the poorest members of the global community, particularly those in Africa.

Follow USA TODAY tech reporter Marco della Cava on Twitter: @marcodellacava