The Linden Dollar (L$) is used in the economy of the virtual world of Second Life. In the Second Life economy, residents buy and sell to one another directly using the Linden, This digital currency is exchangeable for US dollars and other currencies. The residents (read: users) can buy and sell services and virtual goods to one another in a free market. Virtual goods include buildings, vehicles, animation, jewelry and works of art. To gain revenue in Second Life, one must find customers who are willing to pay for the services or goods that one can supply. The existence of virtual land in the Second Life realm creates an active virtual estate market. Originally all land comes from the makers of Second Life (Linden Lab).- Second Life web site