What's old is new at Twitter as Jack Dorsey, the company's first CEO, returns as executive chairman in charge of product. Present CEO Dick Costolo will continue in his role, according to Business Insider.
Dorsey, who has been recently touting his new startup, Square, will stay on as CEO of that venture "now and forever," according to his own Tweet from this morning.
Dorsey was Twitter's first CEO, supplanted by fellow cofounder Ev Williams. Williams stepped aside in late 2010, handing the gig to Costolo.
So the only cofounder we haven't mentioned is Biz Stone -- who reps Twitter with the media more and more, but, apparently at the office, according to BI.