They have Dom Perignon bank accounts, but Red Bull is still in their blood.

Tech geeks across the Facebook empire celebrated the company's IPO and their newfound millions by slugging back energy drinks at all-night code-writing parties.

Legions of the social network's employees, who will be worth an average of $2.9 million apiece on paper when the stock opens trading this morning, dressed for the occasion with matching “Hackathon” T-shirts.

They kicked off the party at their Menlo Park, Calif., headquarters, just hours after the company's 420 million available shares were priced at $38 each.

The festivities were expected to rage through the night until founder Mark Zuckerberg rings the Nasdaq opening bell via video feed at 9:30 a.m.

The Kid Billionaire

CEO Mark Zuckerberg is selling about 30 million shares of Facebook as part of the initial public offering. At $38 each, he pockets $1.15 billion. He will remain Facebook's largest shareholder, will more than 32 percent of Facebook's total shares. At the $38 share price, his stake in the company is worth $19.1 billion.

AGE: 28. Born May 14, 1984.
RESIDENCE: Palo Alto, Calif. Grew up in Dobbs Ferry, N.Y.
EDUCATION: Philips Exeter Academy, class of 2002. Studied computer science at Harvard before dropping out.
CAREER: Co-founded Facebook in his dorm room in 2004. Has served as CEO since.
FAMILY: Mother, Karen; father, Edward; sisters Arielle, Donna and Randi Zuckerberg.

Source: AP

And they had plenty to celebrate.

According to the IPO prospectus, $10 billion in equity will be held by insiders at the social-media site. It's expected to rival the last hot tech stock, LinkedIn, which went public last May and saw its per-share price jump 109 percent in the first day of trading.

A similar pop would double the average Facebook worker's net worth to $5.8 million.

In the hours before Zuckerberg and his troops started their celebration, Facebook fever was at critical mass, with big-brokerage clients scrambling to buy in at the offering price.

“This is worse than not scoring an invitation to the best party in high school,” said Manhattanite Fran Carpentier, 57, a publishing and marketing consultant who couldn't get in on the IPO.

At around 11 a.m. today, the general public will finally get its chance.

Everyone from college students to their grandmothers will be scraping together their savings to buy a piece of the biggest tech IPO in US history.

But the shares won't come cheap. When LinkedIn went public, it closed at $94 a share in a wild first day of trading that sent the price rocketing at one point to $122.

Facebook's IPO is the third largest in US history, putting it just behind General Motors and Visa. The company tops McDonald's and Amazon in market value.

Zuckerberg, who controls 55 percent of Facebook's voting power, saw his net worth rise to $19.1 billion.

The boy-wonder billionaire - who celebrated his 28th birthday Monday - owns 503.6 million shares of the social media behemoth he launched as a Harvard student in 2004.

His net worth will jump an astounding $1 billion for every $2 jump in the stock price.

Zuckerberg's IPO put his net worth above Amazon's Jeff Bezos, who is worth about $18.5 million. And he will likely surpass Mayor Bloomberg, who is worth $19.5 billion.

One person who likely didn't get an invite to Facebook's tech-geek bash is co-founder Eduardo Saverin, who recently renounced his US citizenship and is living in Singapore.

Saverin - whose initial $30,000 investment in Facebook is now worth $2.9 billion - said he will watch the opening Nasdaq bell ring “with close friends,” and will speak to his parents, who live in Miami, by phone.

“Something I would've never imagined was when I put all my life savings into the company, that it would have been an IPO at this level,” Saverin said.

“You never imagine that $30,000 accumulated through your life, through gifts and birthday parties and other events, and investing it in the company would create this type of return.”

Last night's hackathon was the company's 31st.

It's part of a Facebook tradition in which engineers pulled all-nighters to bat around new ideas, concepts and coding. The “like” button, the “timeline” and “Facebook chat” were dreamed up during those sessions.

This time around, in honor of the public offering, the event was open to any worker that wanted in, Facebook insiders said.

“There's a different level of energy. There's a different feel and a period of intensity,” said one attendee.

But not everyone is a Facebook friend. Len Kleinrock, 77 - a member of the 1969 University of California team that helped create the Internet when it found a way to send data between two huge computers - isn't a Facebook user.

“As it is, I am deluged with e-mail,” Kleinrock said. “My friends and colleagues have ready access to me, and I don't really want another service that I would feel obliged to check into on a frequent basis. I do not want more distractions.”

read more about Facebook's IPO at the New York Post.