Mark Elliot Zuckerberg (born May 14, 1984) is an American computer programmer and Internet entrepreneur. He is best known as one of five co-founders of the social networking site Facebook. Zuckerberg is the chairman and chief executive of Facebook, Inc.

Born and raised in New York state, he took up writing software programs as a hobby in middle school, beginning with BASIC, with help from his father and a tutor (who called him a "prodigy"). In high school, he excelled in classic literature and fencing while studying at Phillips Exeter Academy.

He later attended Harvard University, majoring in computer science and psychology. In his sophomore year he wrote a program called Facemash as a "fun" project, letting students on the college's network vote on other students' photo attractiveness. It was shut down within days, but would become a template for his writing Facebook, a program he launched from his dormitory room. With the help of friends, he took Facebook to other campuses nationwide and soon after moved to Palo Alto, California. By 2007, Zuckerberg was a billionaire at the age of 23. By 2010, Facebook had an estimated 500 million users worldwide.

Zuckerberg has since been involved in various legal disputes initiated by others who have claimed a share of the company's profits due to their help in setting it up.

Since 2010 Zuckerberg has been named among the 100 wealthiest and most influential people in the world by Time magazine's Person of the Year, In 2010 a fictionalized account of Zuckerberg creating Facebook while in college and its later start-up phase was made into a movie dramatization, The Social Network.

Early life
Zuckerberg was born in 1984 in White Plains, New York. He is the son of Karen (née Kempner), a psychiatrist, and Edward Zuckerberg, a dentist. He and his three sisters, Randi, Donna, and Arielle, were brought up in Dobbs Ferry, New York. Zuckerberg was raised Jewish, had his bar mitzvah when he turned thirteen, and has since described himself as an atheist.

At Ardsley High School, Zuckerberg had excelled in the classics before transferring to Phillips Exeter Academy in his junior year, where he won prizes in science (math, astronomy and physics) and classical studies (on his college application, Zuckerberg listed the following non-English languages that he could read and write: French, Hebrew, Latin, and ancient Greek) and was a fencing star and captain of the fencing team. In college, he was known for reciting lines from epic poems such as The Iliad.
 
Software developer
Early years
Zuckerberg began using computers and writing software as a child in middle school. His father taught him Atari BASIC Programming in the 1990s, and later hired software developer David Newman to tutor him privately. Newman calls him a "prodigy", adding that it was "tough to stay ahead of him". Zuckerberg also took a graduate course in the subject at Mercy College near his home while he was still in high school. He enjoyed developing computer programs, especially communication tools and games. In one such program, since his father's dental practice was operated from their home, he built a software program he called "ZuckNet", which allowed all the computers between the house and dental office to communicate by pinging each other. It is considered a "primitive" version of AOL's Instant Messenger, which came out the following year.

According to writer Jose Antonio Vargas, "some kids played computer games. Mark created them." Zuckerberg himself recalls this period: "I had a bunch of friends who were artists. They'd come over, draw stuff, and I'd build a game out of it." However, notes Vargas, Zuckerberg was not a typical "geek-klutz", as he later became captain of his prep school fencing team and earned a classics diploma. Napster co-founder Sean Parker, a close friend, notes that Zuckerberg was "really into Greek odysseys and all that stuff", recalling how he once quoted lines from the Roman epic poem Aeneid, by Virgil, during a Facebook product conference.

During Zuckerberg's high school years, under the company name Intelligent Media Group, he built a music player called the Synapse Media Player that used artificial intelligence to learn the user's listening habits, which was posted to Slashdot and received a rating of 3 out of 5 from PC Magazine. Microsoft and AOL tried to purchase Synapse and recruit Zuckerberg, but he chose instead to enroll at Harvard University in September 2002.

College years
By the time he began classes at Harvard, he had already achieved a "reputation as a programming prodigy", notes Vargas. He studied psychology and computer science as well as belonging to Alpha Epsilon Pi, a Jewish fraternity. In his sophomore year, he wrote a program he called CourseMatch, which allowed users to make class selection decisions based on the choices of other students and also to help them form study groups. A short time later, he created a different program he initially called Facemash that let students select the best looking person from a choice of photos. According to Zuckerberg's roommate at the time, Arie Hasit, "he built the site for fun". Hasit explains:

We had books called Face Books, which included the names and pictures of everyone who lived in the student dorms. At first, he built a site and placed two pictures, or pictures of two males and two females. Visitors to the site had to choose who was "hotter" and according to the votes there would be a ranking.

The site went up over a weekend, but by Monday morning the college shut it down because its popularity had overwhelmed one of Harvard's network switches and prevented students from accessing the Internet. In addition, many students complained that their photos were being used without permission. Zuckerberg apologized publicly, and the student paper ran articles stating that his site was "completely improper".

Around the time of Facemash, however, students were requesting that the university develop an internal website that would include similar photos and contact details. According to Hasit, "Mark heard these pleas and decided that if the university won't do something about it, he will, and he would build a site that would be even better than what the university had planned."

Zuckerberg dropped out of Harvard in his sophomore year to complete his project.

Career
Facebook
Main articles: Facebook, History of Facebook, and Timeline of Facebook
Zuckerberg launched Facebook from his Harvard dormitory room on February 4, 2004. An earlier inspiration for Facebook may have come from Phillips Exeter Academy, the prep school from which Zuckerberg graduated in 2002. It published its own student directory, “The Photo Address Book,” which students referred to as “The Facebook.” Such photo directories were an important part of the student social experience at many private schools. With them, students were able to list attributes such as their class years, their proximities to friends, and their telephone numbers.

Once at college, Zuckerberg's Facebook started off as just a "Harvard thing" until Zuckerberg decided to spread it to other schools, enlisting the help of roommate Dustin Moskovitz. They first started it at Stanford, Dartmouth, Columbia, New York University, Cornell, Penn, Brown, and Yale, and then at other schools that had social contacts with Harvard. Samyr Laine, a triple jumper representing Haiti at the 2012 Summer Olympics, shared a room with Zuckerberg during Facebook's founding. "Mark was clearly on to great things," said Laine, who was Facebook's fourteenth user.

Zuckerberg moved to Palo Alto, California, with Moskovitz and some friends. They leased a small house that served as an office. Over the summer, Zuckerberg met Peter Thiel who invested in the company. They got their first office in mid-2004. According to Zuckerberg, the group planned to return to Harvard but eventually decided to remain in California. They had already turned down offers by major corporations to buy out Facebook. In an interview in 2007, Zuckerberg explained his reasoning:

It's not because of the amount of money. For me and my colleagues, the most important thing is that we create an open information flow for people. Having media corporations owned by conglomerates is just not an attractive idea to me.

He restated these same goals to Wired magazine in 2010: "The thing I really care about is the mission, making the world open." Earlier, in April 2009, Zuckerberg sought the advice of former Netscape CFO Peter Currie about financing strategies for Facebook.

On July 21, 2010, Zuckerberg reported that the company reached the 500 million-user mark. When asked whether Facebook could earn more income from advertising as a result of its phenomenal growth, he explained:

I guess we could ... If you look at how much of our page is taken up with ads compared to the average search query. The average for us is a little less than 10 percent of the pages and the average for search is about 20 percent taken up with ads ... That’s the simplest thing we could do. But we aren’t like that. We make enough money. Right, I mean, we are keeping things running; we are growing at the rate we want to.

In 2010, Steven Levy, who authored the 1984 book Hackers: Heroes of the Computer Revolution, wrote that Zuckerberg "clearly thinks of himself as a hacker". Zuckerberg said that "it's OK to break things" "to make them better". Facebook instituted "hackathons" held every six to eight weeks where participants would have one night to conceive of and complete a project. The company provided music, food, and beer at the hackathons, and many Facebook staff members, including Zuckerberg, regularly attended. "The idea is that you can build something really good in a night", Zuckerberg told Levy. "And that's part of the personality of Facebook now ... It's definitely very core to my personality."

Vanity Fair magazine named Zuckerberg number 1 on its 2010 list of the Top 100 "most influential people of the Information Age". Zuckerberg ranked number 23 on the Vanity Fair 100 list in 2009. In 2010, Zuckerberg was chosen as number 16 in New Statesman's annual survey of the world's 50 most influential figures.

In a 2011 interview with PBS after the death of Steve Jobs, Zuckerberg said that Jobs had advised him on how to create a management team at Facebook that was "focused on building as high quality and good things as you are".

Wirehog
A month after Facebook launched in February 2004, i2hub, another campus-only service, created by Wayne Chang, was launched. i2hub focused on peer-to-peer file sharing. At the time, both i2hub and Facebook were gaining the attention of the press and growing rapidly in users and publicity. In August 2004, Zuckerberg, Andrew McCollum, Adam D'Angelo, and Sean Parker launched a competing peer-to-peer file sharing service called Wirehog, a precursor to Facebook Platform applications.

Platform and Beacon

 
Zuckerberg at World Economic Forum, Davos, Switzerland (January 2009)

On May 24, 2007, Zuckerberg announced Facebook Platform, a development platform for programmers to create social applications within Facebook. Within weeks, many applications had been built and some already had millions of users. It grew to more than 800,000 developers around the world building applications for Facebook Platform.

On November 6, 2007, Zuckerberg announced a new social advertising system called Beacon, which enabled people to share information with their Facebook friends based on their browsing activities on other sites. For example, eBay sellers could let friends know automatically what they have for sale via the Facebook news feed as they list items for sale. The program came under scrutiny because of privacy concerns from groups and individual users. Zuckerberg and Facebook failed to respond to the concerns quickly, and on December 5, 2007, Zuckerberg wrote a blog post on Facebook taking responsibility for the concerns about Beacon and offering an easier way for users to opt out of the service.
In 2007, Zuckerberg was named to the MIT Technology Review TR35 as one of the top 35 innovators in the world under the age of 35.

On July 23, 2008, Zuckerberg announced Facebook Connect, a version of Facebook Platform for users.

Legal controversies
ConnectU lawsuits
Harvard students Cameron Winklevoss, Tyler Winklevoss, and Divya Narendra accused Zuckerberg of intentionally making them believe he would help them build a social network called HarvardConnection.com (later called ConnectU). They filed a lawsuit in 2004 but it was dismissed on a technicality on March 28, 2007. It was refiled soon thereafter in federal court in Boston. Facebook counter sued in regards to Social Butterfly, a project put out by The Winklevoss Chang Group, an alleged partnership between ConnectU and i2hub. On June 25, 2008, the case settled and Facebook agreed to transfer over 1.2 million common shares and pay $20 million in cash.

In November 2007, confidential court documents were posted on the website of 02138, a magazine that catered to Harvard alumni. They included Zuckerberg's social security number, his parents' home address, and his girlfriend's address. Facebook filed to have the documents removed, but the judge ruled in favor of 02138.

Saverin lawsuit
A lawsuit filed by Eduardo Saverin against Facebook and Zuckerberg was settled out of court. Though terms of the settlement were sealed, the company affirmed Saverin's title as co-founder of Facebook. Saverin signed a non-disclosure contract after the settlement.
 
Pakistan criminal investigation
In June 2010, Pakistani Deputy Attorney General Muhammad Azhar Sidiqque launched a criminal investigation into Zuckerberg and Facebook co-founders Dustin Moskovitz and Chris Hughes after a "Draw Muhammad" contest was hosted on Facebook. The investigation also named the anonymous German woman who created the contest. Sidiqque asked the country's police to contact Interpol to have Zuckerberg and the three others arrested for blasphemy. On May 19, 2010, Facebook's website was temporarily blocked in Pakistan until Facebook removed the contest from its website at the end of May. Sidiqque also asked its UN representative to raise the issue with the United Nations General Assembly.
 
Paul Ceglia
On June 30, 2010, Paul Ceglia, the owner of a wood pellet fuel company in Allegany County, upstate New York, filed a lawsuit against Zuckerberg, claiming 84% ownership of Facebook and seeking monetary damages. According to Ceglia, he and Zuckerberg signed a contract on April 28, 2003, that an initial fee of $1,000 entitled Ceglia to 50% of the website's revenue, as well as an additional 1% interest in the business per day after January 1, 2004, until website completion. Zuckerberg was developing other projects at the time, among which was Facemash, the predecessor of Facebook, but did not register the domain name thefacebook.com until January 1, 2004. Facebook management dismissed the lawsuit as "completely frivolous". Facebook spokesman Barry Schnitt told a reporter that Ceglia's counsel had unsuccessfully sought an out-of-court settlement.

Pursuant to the contract, Ceglia agreed to pay Zuckerberg $1,000 for StreetFax and $1,000 for PageBook. The contract also refers to The Face Book, a project that was to be completed by January 2004. Ceglia offered a receipt for $1,000, dated six months after the contract, to prove he paid Zuckerberg, but it was not the full amount due, and the contract did not specify what occurs in the event of a default.

In an interview with ABC World News, Zuckerberg stated he was confident he had never signed such an agreement. At the time, Zuckerberg worked for Ceglia as a code developer on a project named "StreetFax". Judge Thomas Brown issued a restraining order on all financial transfers concerning ownership of Facebook until further notice; in response, Facebook removed the case to federal court and asked that the state court injunction be dissolved. According to Facebook, the injunction would not affect their business and lacked any legal basis.

Depictions in media
The Social Network
A movie based on Zuckerberg and the founding years of Facebook, The Social Network was released on October 1, 2010, and stars Jesse Eisenberg as Zuckerberg. After Zuckerberg was told about the film, he responded, "I just wished that nobody made a movie of me while I was still alive." Also, after the film's script was leaked on the Internet and it was apparent that the film would not portray Zuckerberg in a wholly positive light, he stated that he wanted to establish himself as a "good guy". The film is based on the book The Accidental Billionaires by Ben Mezrich, which the book's publicist once described as "big juicy fun" rather than "reportage". The film's screenwriter Aaron Sorkin told New York magazine, "I don't want my fidelity to be to the truth; I want it to be to storytelling", adding, "What is the big deal about accuracy purely for accuracy's sake, and can we not have the true be the enemy of the good?"

Upon winning the Golden Globes award for Best Picture on January 16, 2011, producer Scott Rudin thanked Facebook and Zuckerberg "for his willingness to allow us to use his life and work as a metaphor through which to tell a story about communication and the way we relate to each other.” Sorkin, who won for Best Screenplay, retracted some of the impressions given in his script:

"I wanted to say to Mark Zuckerberg tonight, if you're watching, Rooney Mara's character makes a prediction at the beginning of the movie. She was wrong. You turned out to be a great entrepreneur, a visionary, and an incredible altruist."

On January 29, 2011, Zuckerberg made a surprise guest appearance on Saturday Night Live, which was being hosted by Jesse Eisenberg. They both said it was the first time they ever met. Eisenberg asked Zuckerberg, who had been critical of his portrayal by the film, what he thought of the movie. Zuckerberg replied, "It was interesting." In a subsequent interview about their meeting, Eisenberg explains that he was "nervous to meet him, because I had spent now, a year and a half thinking about him ..." He adds, "Mark has been so gracious about something that’s really so uncomfortable ... The fact that he would do SNL and make fun of the situation is so sweet and so generous. It’s the best possible way to handle something that, I think, could otherwise be very uncomfortable."

Disputed accuracy
Jeff Jarvis, author of the book Public Parts, interviewed Zuckerberg and believes Sorkin has made too much of the story up. He states, "That's what the internet is accused of doing, making stuff up, not caring about the facts."

According to David Kirkpatrick, former technology editor at Fortune magazine and author of The Facebook Effect:The Inside Story of the Company That Is Connecting the World, (2011), "the film is only "40% true ... he is not snide and sarcastic in a cruel way, the way Zuckerberg is played in the movie." He says that "a lot of the factual incidents are accurate, but many are distorted and the overall impression is false", and concludes that primarily "his motivations were to try and come up with a new way to share information on the internet".

Although the film portrays Zuckerberg's creation of Facebook in order to elevate his stature after not getting into any of the elite final clubs at Harvard, Zuckerberg himself said he had no interest in joining the final clubs. Kirkpatrick agrees that the impression implied by the film is "false".

Karel Baloun, a former senior engineer at Facebook, notes that the "image of Zuckerberg as a socially inept nerd is overstated ... It is fiction ..." He likewise dismisses the film's assertion that he "would deliberately betray a friend".

Other depictions
Zuckerberg voiced himself on an episode of The Simpsons, "Loan-a Lisa", which first aired on October 3, 2010. In the episode, Lisa Simpson and her friend Nelson encounter Zuckerberg at an entrepreneurs' convention. Zuckerberg tells Lisa that she does not need to graduate from college to be wildly successful, referencing Bill Gates and Richard Branson as examples.

On October 9, 2010, Saturday Night Live lampooned Zuckerberg and Facebook. Andy Samberg played Zuckerberg. The real Zuckerberg was reported to have been amused: "I thought this was funny."

Stephen Colbert awarded a "Medal of Fear" to Zuckerberg at the Rally to Restore Sanity and/or Fear on October 30, 2010, "because he values his privacy much more than he values yours".

Use of other social networks
Zuckerberg created an account with Google+ soon after the social network was unveiled, saying he sees it as a "validation for his vision" of online social networking. By July 2011, Zuckerberg had become the most followed user on Google+, outranking Google co-founders Larry Page and Sergey Brin. As of March 6, 2012, his ranking has dropped to 184 on the service, behind Page and Brin. His public profile is minimal with one photo and a bio that reads "I make things".

Zuckerberg has maintained a private account on Twitter under the username "zuck", though in 2009 he revealed that the public account "finkd" also belonged to him.

Philanthropy
Zuckerberg donated an undisclosed amount to Diaspora, an open-source personal web server that implements a distributed social networking service. He called it a "cool idea".

Zuckerberg founded the Start-up: Education foundation. On September 22, 2010, it was reported that Zuckerberg had arranged to donate $100 million to Newark Public Schools, the public school system of Newark, New Jersey. Critics noted the timing of the donation as being close to the release of The Social Network, which painted a somewhat negative portrait of Zuckerberg. Zuckerberg responded to the criticism, saying, "The thing that I was most sensitive about with the movie timing was, I didn’t want the press about The Social Network movie to get conflated with the Newark project. I was thinking about doing this anonymously just so that the two things could be kept separate." Newark Mayor Cory A. Booker stated that he and New Jersey Governor Chris Christie had to convince Zuckerberg's team not to make the donation anonymously.

On December 9, 2010, Zuckerberg, Bill Gates, and investor Warren Buffett signed a promise they called the "Giving Pledge", in which they promised to donate to charity at least half of their wealth over the course of time, and invited others among the wealthy to donate 50% or more of their wealth to charity.

Personal life
At a party put on by his fraternity during his sophomore year, Zuckerberg met Priscilla Chan, a fellow student who he began dating in 2003. Chan is the child of a Chinese-Vietnamese refugee, who arrived in the U.S. after the Fall of Saigon, was born in Braintree, Massachusetts, a suburb of Boston, and is a 2003 graduate of Quincy High School. In September 2010, Zuckerberg invited Chan, by then a medical student at the University of California, San Francisco, to move into his rented Palo Alto house. Zuckerberg studied Mandarin Chinese in preparation for the couple's visit to the People's Republic of China in December 2010.

On May 19, 2012, Zuckerberg and Chan married in Zuckerberg's backyard in a celebration also marking her graduation from medical school. Chan has a medical degree, and, according to some sources, is planning to begin interning and residencing towards becoming a pediatrician in 2012 or is a pediatrician currently.

On Zuckerberg's Facebook page, he listed his personal interests as "openness, making things that help people connect and share what's important to them, revolutions, information flow, minimalism". Zuckerberg sees blue best because of red–green colorblindness; blue is also Facebook's dominant color.