Facebook officially declared its plans for an Initial Public Offering today, marking the first step toward becoming a publicly traded company on the stock market. The company, famously launched by Mark Zuckerberg from his Harvard dormroom in 2004, says it will sell $5 billion worth of stock in the IPO.

Once trading begins, many analysts believe Facebook's overall valuation could reach as much as $100 billion, making it the priciest launch in history for an Internet company.

In its filing with the Securities and Exchanges Comission, Facebook declares that it has a whopping 845 million active monthly users. Last year, the company brought in $3.7 billion in revenue, not an exceptionally high number in itself, but one that most believe will multiply rapidly in coming years. The 3.7 figure is already 88 percent more than what Facebook made in 2010, and five times what it made in 2009.

In a statement, Zuckerberg said that his company wants to sell stock now in order to fund big plans for the future.

“Simply put: we don’t build services to make money; we make money to build better services,” he said.

[via NYT]