Linden Research, Inc., doing business as Linden Lab, is an American technology company that is best known as the developer of Second Life.

Second Life is an online multimedia platform that allows people to create an avatar for themselves and then interact with other users and user-created content within a multi-user online virtual world. Developed and owned by the San Francisco–based firm Linden Lab and launched on June 23, 2003, it saw rapid growth for some years and in 2013 it had approximately one million regular users. Growth eventually stabilized, and by the end of 2017 the active user count had declined to "between 800,000 and 900,000". In many ways, Second Life is similar to massively multiplayer online role-playing games; nevertheless, Linden Lab is emphatic that their creation is not a game: "There is no manufactured conflict, no set objective."