New Delhi: Social networking site Facebook on Monday turned nine.

Today, Facebook has over one billion active users and the counting is going on rapidly.

The most popular social networking site was founded by Mark Zuckerberg and his four friends as a sophomore at the Harvard University in 2004.

Some of the major developments since Facebook came into being are:

In September 2004, Facebook introduced the Wall, which allows people to write personal thoughts for which Zuckerberg faced a lawsuit for stealing the idea from some other firm.

Later in a bid to further expansion, Facebook included high schools in the year 2005.

In 2006, Facebook introduced News Feed which actually gathers all your Wall posts in one place.

In October 2007, Facebook sold 1.6 percent stake to Microsoft for US 240 million.

Further, it also introduced Beacon program, which is a feature that broadcasts people’s activities on dozens of outside sites in November 2007.

In April 2008, Facebook introduced chat feature.

In the year 2009, Facebook’s “Like” feature was introduced.

Further, in 2010, location feature was added to know the exact location of users and friends.

In the year 2011, Facebook introduced Timeline, a new version of the profile page.

Later, in January 2012, Timeline feature was made mandatory by the social networking website.