Clark is a high school dropout from Plainview, Texas. After getting his GED, B.S. and ph.D., he went on to become a professor of electrical engineering at Stanford. He founded visual effects company Silicon Graphics in 1982 and Netscape with Marc Andreessen in 1994.
With the success of Netscape and its incredibly popular Navigator browser, Clark and Andreessen became the first to capitalize on the World Wide Web. Clark's wealth grew after the company's extremely successful IPO in August 1995. He later became a billionaire thanks to timely investments in Apple and Facebook.
Clark has developed a number of expensive hobbies in the 20 years since Netscape's IPO. As a former Navy man, sailing is perhaps his number one passion. His latest watercraft is the new 100-foot monohull sailboat he named "Comanche." Though he hasn't shared how much the boat cost to build, he told the Australian Associated Press, "Boats of this type are sort of like building a Formula 1 car. They are expensive."
"Comanche" faced its first test in December, when Clark's crew competed in a 630-mile race from Sydney, Australia to Hobart, the capital of Tasmania. Though the boat finished second in the race, Clark has big plans for the next few months. "I do think it will break quite a few records," he said to the Australian Associated Press.
Clark's first yacht was "Hyperion," which he customized to essentially be a computer on the water. The 157-foot J-class yacht, which has since been sold for an undisclosed amount, has 22 touchscreens and a total 40 miles of wiring.
He also owns two other J-class yachts: 136-foot "Hanuman" and 295-foot "Athena." He listed them for a combined $113 million in 2012, though the listing price for "Athena" recently dropped from $95 million to $75 million.
Clark has been married four times. He married current wife Kristy Hinze in an exclusive ceremony on Virgin Gorda in the British Virgin Islands in 2009. 35-year-old Hinze is an Australian model and TV personality who has appeared in Sports Illustrated and the Victoria's Secret catalogue. The couple has two young daughters together.
To celebrate Clark's 70th birthday last year, Hinze threw a three-day party at the luxurious Casa de Campo resort in the Dominican Republic. The soiree included a live performance from Jason Mraz.
Clark's family has many connections to the tech community. Kathy Clark, his daughter from a previous marriage, is married to YouTube cofounder Chad Hurley.
Clark is also well-known in some Hollywood circles. He was the executive producer of "The Cove," a documentary that exposes secret dolphin-hunting practices taking place in a hidden cove in Taiji, Japan. The film won the Academy Award for Best Documentary in 2009. Here he poses with actor Ben Stiller at a special screening of "The Cove" in New York City.
Clark certainly has the real estate portfolio you'd expect from a billionaire. He recently paid $37 million for the Upper East Side townhouse that previously belonged to Listerine heiress Bunny Mellon.
And last month the New York Post revealed that the Netscape billionaire was the mystery buyer of Ron Howard's Armonk, N.Y. home, which he paid $37.5 million for in July 2014. The home has plenty of luxurious amenities, including a pool, sports facility, barn, greenhouse, and observatory.
In 1999, Clark paid $11 million for the opulent Il Palmetto estate in Palm Beach, Florida. Originally built in 1930 by noted architect Maurice Fatio, the mansion has been extensively renovated by Clark.
He also previously owned a 6,200-square-foot apartment at Miami's posh Setai Resort and Residences. He sold the penthouse for $21.5 million in 2011.
Though he spends much of his time in Florida and New York and on the high seas, he previously made his home in the ritzy Silicon Valley town of Atherton. According to local legend, Clark once had to come up with a creative solution when he discovered that his neighbors could see directly into his home. He wanted to build a taller fence, but since that would be against Atherton zoning rules, he brought in enough dirt to build a hill in his backyard, raising the height of the fence.
But homes aren't the only things this billionaires collects. A longtime wine connoisseur, he has a collection that's rumored to contain as many as 40,000 bottles, mostly from the Burgundy region of France. "I may have gotten overly enthusiastic about it," Clark told Sotheby's. "I have more wine than I can ever drink." In November 2014, he sold a selection of wines that fetched nearly $2.6 million at a Sotheby's auction.
He also has an extensive art collection and is rumored to own pieces by such big names as Monet, Matisse, Picasso, and Van Gogh.
He owns a Gulfstream jet, which he uses for both business and pleasure.
According to a particularly memorable account from Michael Lewis' book "The New New Thing," Clark owned a McDonnell Douglas helicopter that he learned to fly himself. According to Lewis, Clark loved the helicopter so much he had considered buying the company that made it.
Clark is a noted philanthropist as well. In 1999, he donated $150 million to fund a biomedical engineering center at Stanford. That donation remains one of the largest gifts the university has ever receieved. He also makes yearly donations to New York's Perlman Music Program.