If you’d founded a tech company worth billions of dollars, what would you do with your cash?That’s a high-class problem faced by the moguls on this list.
Naturally, many of them buy expensive things, like cars, houses, planes—even islands.
But even if you’re Larry Ellison, with a seemingly endless appetite for that stuff, there comes a time when you want to do more.
Maybe it’s solving the world’s problems, or just indulging in a geeky fantasy.
Oracle cofounder and CEO Larry Ellison is known for pet projects like running the America's Cup sailboat race series, buying homes on Malibu's 'Billionaire's Beach,' and turning the Hawaiian island of Lanai into a sustainable living lab.
But he says his biggest philanthropic endeavour is medicine.
'I have a medical foundation called, very creatively, the Ellison Medical Foundation,' Ellison said in an interview at the D: All Things Digital conference last year. 'We are focused on diseases related to ageing--I mean, for obvious reasons.' (Ellison is now 68.)
Ellison spent about $1 billion on this foundation.
Through the Bill and Melinda Gates Foundation, the Microsoft cofounder is working on a lot of social issues in health, education, and agriculture.
But one problem that really caught Gates' attention is ... poop. The foundation sponsored a 'Reinvent the Toilet' fair. Gates himself judged the entries and announced the winners.
He was looking for methods 'for capturing and processing human waste and transforming it into useful resources,' Gates said in a blog post announcing the winners.
Paul Allen, Microsoft's other billionaire cofounder, also has a long list of pet projects that includes owning multiple pro sports teams, building a rock-and-roll museum, collecting vintage WWII planes, and more.
He's also invested a half billion dollars into the Allen Institute for Brain Science. Its mission is to figure out exactly how the brain works and how to solve diseases like Alzheimer's, which his mother suffered from.
Another goal of the institute is to replicate the brain and build machines with human intelligence.
Hamburger is a $100 billion market just waiting for technology to disrupt it.
So says top venture capitalist Vinod Khosla, who is funding a stealth startup that turns protein, fat, and fibre from plant sources into a juicy, beefy-tasting patty.
'There are no cows involved, but you can't taste the difference,' he promised.
He's also backing a startup working on fake cheese; one working on less-salty salt; and Unreal, a candy maker which promises healthier sweets.
Twitter cofounder Biz Stone is an outspoken vegan. So it's not surprising that animal rights is one of the areas championed by the Biz and Livia Stone Foundation.
Like Khosla, who similarly eschews meat, Stone has backed a company making fake meat.
Beyond Meat was funded by Stone and another Twitter cofounder, Ev Williams. It makes realistic fake chicken and will ramp up availability in 2013.
Venture capitalist Peter Thiel, a billionaire thanks largely to his early backing of Facebook, is financing medical research that could help people live to be 150 years or more.
'There are all these people who say that death is natural, it's just part of life, and I think that nothing can be further from the truth,' Thiel has said.
The Thiel Foundation contributes to a number of anti-ageing research projects, including Ray Kurzweil's Singularity Institute, which works on artificial intelligence, and Aubrey de Grey's Strategies for Engineered Negligible Senescence, which hopes to reverse ageing altogether.
In 2008, Google cofounder Sergey Brin revealed a surprisingly personal story about his mum having Parkinson's disease.
Through 23andMe, a genetic-testing startup cofounded by his wife, Anne Wojcicki, Brin discovered he has a good chance of getting Parkinson's, too. But the startup also made a medical discovery that could save his life.
23andMe is now backed by Google's venture-capital arm, Google Ventures, and others.
Its mission, while broadly looking at gene-linked diseases, includes finding a way to save Brin and others from ths terrible illness.
Amazon CEO Jeff Bezos is spending $42 million to build a giant clock that will chime every year, decade, century, and millennium--for the next 10,000 years.
He's got other interesting pet projects too, like Blue Origin, a space-travel company that wants to take astronauts to the International Space Station.
In 2011, he hired undersea experts to find the engines that sent the Apollo 11 rocket into space. In March 2012, they succeeded in locating them.
Michael Dell run a charitable foundation with his wife, Susan, dedicated to helping kids in urban poverty.
That's a wonderful mission.
Dell also puts his money into more offbeat causes.
In 2010, his private investment company, MSD Capital, bought the Magnum Collection. It includes more than 180,000 of some of the nation's most important and memorable photographs taken since 1947. He houses the collection at the Ransom centre museum in Austin, Texas.
Marc Benioff is famous for his 1-1-1 philanthropic model in which companies dedicate a percentage of profits, equity, and employee time to nonprofit work.
As Benioff points out, this differs from the another popular method, like The Giving Pledge, in which billionaires collect money throughout their lives and then give it away at the end.
Benioff has a lot of pet projects, especially around his beloved city of San Francisco. But he's best known for his $100 million donation for the 180-bed UCSF Benioff Children's Hospital.
He was drawn to UCSF because of its 'pioneering work with fetal surgery,' he said in an interview with Forbes.
Dustin Moskovitz, a billionaire Facebook cofounder who went on to launch an enterprise startup, Asana, wants to solve poverty-related disease.
His foundation, Good Ventures, gives money to causes recommended by GiveWell, a nonprofit run by Moskovitz's girlfriend, former Wall Street Journal reporter Cari Tuna.
Good Ventures donated $500,000 to fight malaria and another $250,000 to fight schistosomiasis, a disease caused by parasitic worms.
Yammer founder David Sacks, a member of the PayPal Mafia, is also a Hollywood hitmaker.
Through his production company Room 9, Sacks produced the film 'Thank You For Smoking,' which grossed some $39 million worldwide.
That wasn't Room 9's only film. It also produced 'Dumbstruck,' a movie about professional ventriloquists.
Sacks is also interested in startups that are taking on older industries that haven't really figured out the Internet yet. He invested in Uber, which successfully disrupted the taxi industry. But another investment, Cherry, shut down its mobile car-wash service last month.
Billionaire SAP cofounder Hasso Plattner invested $35 million into the Hasso Plattner Institute of Design at Stanford University, focused on product design. He also gave about $265 million to the Hasso Plattner Institute, which focuses specifically on enterprise-software design.
He's also donated millions to fighting AIDS. He hosts concerts to raise AIDS awareness at his luxury golf estate in South Africa, a country hard-hit by the disease.
He's also known as another sailboat racing enthusiast whose pro racing team has faced-off with arch business enemy Larry Ellison. He once even mooned Ellison on the high seas--or at least one of Ellison's boats, at any rate.
Cisco CEO John Chambers wants to kill cancer dead.
A year ago he donated $750,000 for cancer research at West Virginia University. Both of his parents were doctors who graduated from WVU.
Chambers has been known to fight cancer in more personal ways, too, particularly when it strikes Cisco employees. Chambers once personally arranged a second opinion for a Cisco employee who was diagnosed with a terminal, inoperable form of cancer, a former Cisco exec told us. That employee got the surgery and survived.
In 2010, Mark Zuckerberg started his brand-new education foundation with a bang: He gave $100 million to the public school system of Newark, New Jersey.
And he wasn't even from New Jersey. He said he picked Newark after a year of research because he felt this school system had the pieces in place to improve itself. It was also a challenge grant, meaning Newark had to find donors to match the money.
That year he also signed the Giving Pledge and vowed to give away most of his money to more education and health charities.