Facebook, the rapidly growing social networking site, has flexed its muscle before a widely expected listing on the stock market by buying Parakey, the fledgling web-based operating system.

The acquisition, Facebook's first, will make it easier for the site's users to upload and share content on the site, and build on its strategy of allowing developers to write applications for the Facebook platform, the company said.

Parakey, which has been developed by the founders of Mozilla Firefox, the open-source internet browser, aims to create a more seamless integration between storing content on a computer and sharing it through online platforms, such as Facebook.

By taking the capabilities of an operating system — such as content management — and moving them online, Parakey aims to remove the step of having to store photographs, say, on a computer before uploading them to sites that host such content, such as MySpace, Facebook and Flickr.

"It's a web operating system that can do everything a [regular] OS can do," Mr Ross has said.

The Parakey founders' background in open source also meant that the system would integrate well with Facebook's policy, announced in May, of allowing developers to write applications that can be shared by Facebook users, such as the already hugely popular "Super Poke" function, the two companies said in a statement.

Financial details of the deal were not disclosed.