The social networking site Facebook said late Thursday that it acquired Parakey, a startup formed by the co-founders of Mozilla Firefox.

Financial terms were not disclosed.

The purchase, which represents Facebook's first acquisition, will give the website access to Blake Ross and Joe Hewitt, the developers behind the popular internet browser Firefox, and other open-source applications.

The acquisition comes as Mark Zuckerberg, Facebook's 23-year-old founder and CEO, attempts to transform Facebook from a social networking site into a platform for web services.

"Blake and Joe built the Firefox web browser and then turned to the developer community to build on top of the foundation they'd established, not unlike what we've done with Facebook Platform,' said Zuckerberg. "The work they've done with Firefox and Parakey and their approach to building products fit right in at Facebook.'

The website has surged to become the No. 2 social networking site, behind New Corp's Myspace. According to Internet statistics firm ComScore, unique visits to Facebook rocketed 89 percent between May 2006 and May 2007, from about 14 million unique visitors to 26.6 million.

Facebook's backers believe the web-property may be worth up to $8 billion. Last year, Facebook reportedly turned down an offer as high as $1 billion from Yahoo! There is speculation that the privately held firm could choose to be listed on a stock exchange and make an initial public offering.

Next week, Facebook representatives will appear at a hearing in an attempt to convince a federal court to discard claims that Zuckerberg stole source code and graphic designs from his Harvard university classmates which started ConnectU.com.