Second Life (SL) is a privately-owned, partly subscription-based 3-D Virtual world, made publicly available in 2003 by San Francisco-based Linden Lab, founded by former RealNetworks CTO Philip Rosedale. The Second Life "world" resides in a large array of servers that are owned and maintained by Linden Lab. The Second Life client program provides its users (referred to as "Residents") tools to view and modify the SL world and participate in its economy.