(CNN) -- Facebook's Mark Zuckerberg and his wife were the second-biggest charitable donors in the United States last year, appearing behind only billionaire Warren Buffett on a list of the nation's most generous philanthropists.
Zuckerberg, along with wife Priscilla Chan, gave roughly half a billion dollars ($498.8 million) to the Silicon Valley Community Foundation, according to The Chronicle of Philanthropy
The group released its annual Philanthropy 50 over the weekend.
The Facebook founder and CEO was one of three tech-industry titans in the list's top five.
The Silicon Valley Community Foundation issues grants for a host of causes in the San Francisco area. In 2012, its charitable causes ranged from programs to teach immigrants English, to groups providing food and shelter to the needy, to funds for victims of the California wildfires.
Zuckerberg donated 18 million Facebook shares to the foundation in December.
Microsoft co-founder Paul Allen was fourth, with $309 million in contributions, mostly to the Allen Institute for Brain Science.
And Google co-founder Sergey Brin and wife Anne Wojcicki, co-founder of genetic-testing company 23andME, were fifth, putting $223 million into their Brin Wojcicki Foundation.