He stepped down in 2008, and Linden Lab went through a series of caretaker CEOs in the form of Mark Kingdon, Rosedale (who returned as CEO for just four months), and Bob Komin. And in the aftermath of the dotcom bust, he managed to launch Second Life in 2003.
Philip Rosedale started Linden Lab in 1999 during the dotcom boom.
But Second Life, for all of its endurance and persistence, has never really become as mainstream as it could be.