Social networking site Facebook has bought Parakey, a tiny startup that had been developing software it bills as a web-based operating system.

Parakey has not actually shipped a product, but is in the process of developing technology it says combines the best of the desktop and web-based software world. In a November 2006 interview Parakey founder Blake Ross described the company's eponymous product as "a web operating system that can do everything an OS can do."

Ross and Parakey's other founder Joe Hewitt will work on Facebook's site as well as the Facebook Platform, a set of application program interfaces (APIs) that developers can use to write applications for the social networking site.

Previously the two entrepreneurs had been co-founders of the Firefox open source browser project. They formed Parakey in 2006.

Founded in 2004, the privately held Facebook boasts 31 million users. Parakey is the company's first acquisition.

Financial terms of the purchase were not disclosed.