Twitter marks its 10th anniversary today, with the social media site having hosted some of the biggest social movements of the last 10 years, yet uncertainty still hangs over its future.

Twitter has named co-founder and interim chief executive Jack Dorsey as its permanent CEO, ending months of speculation about who would take the reins at the company.

Twitter’s departing chief Dick Costolo says that while he is confident in the current direction of the company, he also is willing to let the next CEO make the changes the person wants to make.

As Twitter chief executive officer Dick Costolo’s departure was cheered by stockholders, his fans struck a different note, flooding the micro-blogging site he has steered for nearly five years with messages of gratitude and support.

Twitter’s chief executive has taken personal responsibility for the social network’s problems in dealing with abuse reported by users.

Twitter’s slowing user growth pushed the stock to the lowest since last year’s market debut.

As Twitter looks to broaden its appeal beyond its 241m users, it is introducing a redesign of profile pages that includes bigger photos, more user controls, and a distinct resemblance to Facebook.

Twitter co-founder Evan Williams is stepping down as the short-messaging service's chief executive officer.