Gates has been open about his decision not to leave his $84.9 billion fortune to his three children. They will reportedly inherit just a small slice, about $10 million each.
"I definitely think leaving kids massive amounts of money is not a favor to them," he said in a Reddit AMA.
He founded the Bill & Melinda Gates Foundation in 1994, and it currently has more than $38 billion in assets. Gates also teamed up with longtime friend Warren Buffett to start a campaign called "The Giving Pledge," which encourages other billionaires to donate at least half of their fortune to charity.
AOL co-founder Steve Case
Case helped millions of Americans get online, and now he's donating much of his wealth to developing other technologies.
He founded the Case Foundation in 1997, which focuses on using technology to make philanthropy more effective. He also started an investment firm called Revolution, which invests in startups outside of Silicon Valley, and signed the Giving Pledge.
"We share the view that those to whom much is given, much is expected. We realize we have been given a unique platform and opportunity, and we are committed to doing the best we can with it," he and wife Jean wrote. "We do not believe our assets are 'ours' but rather we try to be the responsible stewards of these resources."
Salesforce CEO Marc Benioff
Benioff recently launched a campaign called SF Gives, which challenged tech companies to raise $10 million for San Francisco-based nonprofit programs in just 60 days.
He's encouraged other corporations to follow his 1/1/1 model, which says that a company should donate 1% of its equity, 1% of its employees' time, and 1% of its resources to philanthropic efforts.
"In 2001, I publicly stated that we intend to give away the vast majority of our wealth during our lifetime," the couple said in their pledge letter. "Our view is fairly simple. We have more money than our family will ever need. There’s no need to hold onto it when it can be put to use today, to help solve some of the world’s most intractable problems."
They've also donated eBay shares to the Omidyar Network, their philanthropic investment firm, and are the single biggest private donors in the fight against human trafficking.
He and wife Betty signed Gates' Giving Pledge in 2012.
"We are pleased to be a part of the Giving Pledge not only because we are able to commit these funds, but because we believe they can lead to real learning and measurable change," they said.
Tesla CEO Elon Musk
Musk may have five young boys from his first marriage — one set of twins and one set of triplets — but he's already donated much of his $12.9 billion fortune to renewable energy, science and engineering education, and pediatric health.
Page, on the other hand, has a somewhat unique idea for what he would like to happen to his wealth.
He once told Charlie Rose that instead of giving his billions to his two children, he would rather give it to entrepreneurs like Elon Musk, who are coming up with big ideas to change the world.
"[Musk] wants to go to Mars. That’s a worthy goal," he said. "We have a lot of employees at Google who’ve become pretty wealthy. You’re working because you want to change the world and make it better; if the company you work for is worthy of your time, why not your money as well? We just don’t think about that. I’d like for us to help out more than we are."
Spanx CEO Sara Blakely
Sara Blakely, the CEO of Spanx, became the first woman to sign the Giving Pledge in 2013 and commit to donating the majority of her wealth to charities, specifically aimed for women.
When she told her then-three year old son that she was going to give away half her money, he reportedly said, "Okay, Mommy, can we do a puzzle now?"
"I pledge to invest in women because I believe it offers one of the greatest returns on investment. I am committed to the belief that we would all be in a much better place if half the human race (women) were empowered to prosper, invent, be educated, start their own businesses, run for office – essentially be given the chance to soar!" her letter said.
"Warren Buffett personally asked me to write this letter because he said I would be 'setting an example' and 'influencing others' to give. I hope he's right," his letter to the Giving Pledge said in August 2010.
Despite committing the majority of his wealth to charity, he also gave his children Oracle stock when they were still babies (and the company was also young). Now that both the stock and company are worth a lot more, he reportedly wants to teach them charitable giving, too.
Microsoft co-founder Paul Allen
While Paul Allen doesn't have any direct descendants, his family is actively involved in his philanthropy.
"I've planned for many years now that the majority of my estate will be left to continue the work of the Foundation and to fund non-profit scientific research, like the ground breaking work being done at the Allen Institute for Brain Science," he said in his Giving Pledge letter.
Asana CEO Dustin Moskovitz
Facebook's third employee, Dustin Moskovitz, is one of the youngest self-made billionaires to have signed the Giving Pledge.
"As a result of Facebook’s success, I’ve earned financial capital beyond my wildest expectations. Today, I view that reward not as personal wealth, but as a tool with which I hope to bring even more benefit to the world," he said in his letter.
Moskovitz and his partner, former Wall Street Journal reporter Cari Tuna, established Good Ventures as a philanthropic foundation to help distribute his wealth. Moskovitz is also now founder and CEO of Asana, a collaboration software company.
Facebook COO Sheryl Sandberg
Sheryl Sandberg, along with her late husband Dave Goldberg, signed the Giving Pledge in 2014 to give away half of her wealth. While the couple didn't specify a cause, we have a feeling Sandberg's book "Lean In" might be a pretty strong indication of where their money ends up.
Dave Goldberg tragically died in May after an accident while exercising in Mexico, leaving Sandberg to care for their two children.
Virgin Group founder Richard Branson
Richard Branson's children are philanthropists in their own right: Their son Sam set up a production company, Sundog Pictures, and their daughter Holly is involved in Big Change Charitable Trust, according to their 2013 Giving Pledge letter.
The Virgin Group founder, and his wife Joan, signed the Giving Pledge in 2013 to give away half their wealth after they realized after several house fires that money does not lead to happiness.
"Stuff really is not what brings happiness. Family, friends, good health and the satisfaction that comes from making a positive difference are what really matters," Branson said in the announcement.
Netflix founder and CEO Reed Hastings and his wife Patti Quillin signed the Giving Pledge in 2012, when his net worth was valued only at $280 million. A new entrant on Forbes' World's Billionaires list, Hastings now has a net worth of at least $1.6 billion.
Hastings has an interest in education after he served as president of the California Board of Education from 2000 to 2004. The press release announcing their Giving Pledge hinted that it that might be where they put some of their money since they "are active in educational philanthropy and politics with a specific focus on charter schools."
Zuckerberg announced the birth of his daughter Max December 1. In a Facebook post announcing her arrival, Zuckerberg shared that he and wife Priscilla Chan plan to give away most of their wealth, rather than pass it on to Max.
He shared the news in a letter addressed to his newborn daughter: "As you begin the next generation of the Chan Zuckerberg family, we also begin the Chan Zuckerberg Initiative to join people across the world to advance human potential and promote equality for all children in the next generation. Our initial areas of focus will be personalized learning, curing disease, connecting people and building strong communities. We will give 99% of our Facebook shares — currently about $45 billion — during our lives to advance this mission. We know this is a small contribution compared to all the resources and talents of those already working on these issues. But we want to do what we can, working alongside many others."
The couple gave $75 million in February 2015 to the San Francisco General Hospital, allowing it to add two trauma rooms, three operating rooms and to double the size of its emergency room.