Faces of Facebook: Who's Who in 'The Social Network'?

Oct. 1, 2010— -- Mark Zuckerberg may the biggest face attached to Facebook, but he's not the only one. "The Social Network," the controversial story about the world's most powerful social network, has a colorful cast of characters -- on screen and off.

This weekend, "The Social Network," the highly-anticipated movie about Facebook's founding, opens in theaters around the country to give movie fans Hollywood's take on the college kids and computer crackerjacks behind the wildly-successful website.

It is based on a book that is widely understood (at the very least) to be dramatized. Zuckerberg himself told ABC News that the movie is "fiction."

Still, though some of the movie's events may be in dispute, the characters are real.

If you want to learn a bit more about the faces behind Facebook, take a look below.

Mark Zuckerberg

The man of the moment, Mark Zuckerberg, is the 26-year-old billionaire who founded Facebook from his Harvard dorm room in 2004. As if the new movie wasn't already shining a bright enough spotlight on the young CEO, Zuckerberg set tongues wagging last week when he announced a $100 million charitable donation to public schools.

The movie depicts him as a girl-crazy computer nerd desperate to gain access to the university's refined and exclusive social clubs. But some in Silicon Valley say Zuckerberg, who grew up in Dobbs Ferry, N.Y., is motivated by data, not dating.

"From the beginning, what fascinated him about Facebook was having the sheer efficiency ... taking all that complex data and making it, within seconds, work for you," Sarah Lacy, a longtime Silicon Valley reporter and author of "Once You're Lucky, Twice You're Good," told ABCNews.com in a June 2009 interview.

According to a recent New Yorker profile on Zuckerberg, he has been dating his current girlfriend, Priscilla Chan, since 2003, with a short interruption. In a recent interview with Oprah Winfrey, he let cameras videotape the modest home he shares with Chan in Palo Alto, Calif., and said she played an influential role in his decision to fund public schools.

Forbes Magazine last week released its list of the 400 richest Americans and ranked Zuckerberg 35th, ahead of even Apple's CEO, Steve Jobs, with an estimated worth of $6.9 billion.

Eduardo Saverin

Without Saverin, "The Social Network" might never have been.

According to Ben Mezrich, the author of "The Accidental Billionaires," the book upon which the movie was based, Saverin made the whole thing possible.

"Without him this story could not have been written," he wrote in his book's author's note.

Zuckerberg's estranged Facebook co-founder, Saverin gave Mezrich much of the material he used for the book, which then informed the movie.

He also gave Facebook its first infusion of cash and was the company's first CFO. But over time, the relationship between the two co-founders soured.

Saverin, who reportedly first owned 30 percent of the company, watched his share dwindle to less than one percent. He later sued Facebook and, through a settlement, was returned to the masthead as a Facebook co-founder.

According to his Facebook page, the Sao Paulo-born Harvard graduate is now a technology entrepreneur and investor.

Chris Hughes

Now, Facebook employs a staff of public relations professionals. But in the beginning, it was just Chris Hughes.

One of Zuckerberg's dorm-mates and a Facebook co-founder, Hughes was charged with promoting and speaking on behalf of the social networking site in its earliest days.

Later, he moved on to helping Barack Obama's campaign galvanize supporters online.

Hughes' most recent venture is Jumo, a social network for non-profit groups that will launch later this year.

Dustin Moskwitz

Another Facebook co-founder who has been with Zuckerberg since Facebook's early dorm-room days, Moskowitz is also a young billionaire thanks to the social networking giant.

He was Facebook's first CTO and stayed with the company until 2008. In that year, he left to start a software company called Asana that helps individuals and small businesses with collaboration.

According to Forbes, he is the 290th richest American, with a net worth of $1.4 billion.

Sean Parker

A co-founder of Napster, Sean Parker is ever the entrepreneur.

Aside from Facebook and Napster, Parker helped launch Causes, a Facebook application to help organize charitable giving, and now is a managing partner at the Founders Fund, a venture fund.

The founding president of Facebook, he left the company after a cocaine arrest, though charges never were filed.

According to a recent Vanity Fair article about the 30-year-old, true to the movie, he's known for a penchant to party and is worth about $1 billion, thanks to his share in Facebook.

Cameron and Tyler Winklevoss

These Olympic rowers drive much of the drama in "The Social Network." Along with their Harvard classmate, Divya Narender, they contend that Zuckerberg stole their idea for a social network based at Harvard.

Claiming that Zuckerberg used their code for their social network -- Harvard Connection and later ConnectU -- the brawny blond twins sued Facebook and received a reported $65 million in a settlement.

Currently, the "Winklevi," as they are referred to in the movie, are pursuing MBAs at Oxford University.

At a recent screening of "The Social Network" in New York, Cameron Winklevoss told the New York Daily News, "The film is nonfiction. ... Mark Zuckerberg seems to be the only person in the world capable of commenting on the veracity of a film he has not seen. 'Clairvoyant' should be added to his business card."