Facebook, the world's most popular social networking site, marked its eighth anniversary on Saturday.

The site, which almost single-handedly redefined the idea of social media, was started exclusively for Harvard students. However, in almost no time at all it spread throughout the world, and today it has more than 800 million active subscribers.

While Mark Zuckerberg is best known as the man who built Facebook, the company has three other co-founders - all college roommates and fellow students of Harvard University - Eduardo Saverin, Dustin Moskovitz and Chris Hughes.

Before its public launch, it was called "thefacebook.Com". The site was later renamed and launched - we know today simply as "Facebook".

Facebook, which is available in 70 languages, has placed Zuckerberg at the top of the list of youngest billionaires and also helped a lot of start-ups, non-profits and other companies grow, interact and increase sales.

It now seems almost impossible to imagine life without witty status updates, friend requests, relationship statuses or photo tags.

The social site has recently turned up with more interactive features like chat, the Timeline and the subscription button.