Second Life
Second Life is an online virtual world
Virtual world
A virtual world is an online community that takes the form of a computer-based simulated environment through which users can interact with one another and use and create objects. The term has become largely synonymous with interactive 3D virtual environments, where the users take the form of...

 developed by Linden Lab
Linden Lab
Linden Research, Inc., d/b/a Linden Lab, is a privately held American Internet company that is best known as the creator of Second Life....

. It was launched on June 23, 2003. A number of free client program
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....

s, or Viewers, enable Second Life users, called Residents
Resident (Second Life)
- Activities of residents :Residents engage in many activities, just as people do in real life. Unlike real life, there is no biological need to seek nourishment or shelter. Thus some activities that would be necessary in the real world are purely voluntary leisure pursuits...

, to interact with each other through avatars
Avatar (computing)
In computing, an avatar is the graphical representation of the user or the user's alter ego or character. It may take either a three-dimensional form, as in games or virtual worlds, or a two-dimensional form as an icon in Internet forums and other online communities. It can also refer to a text...

. Residents can explore the world (known as the grid), meet other residents, socialize, participate in individual and group activities, and create and trade virtual property
Virtual good
Virtual goods are non-physical objects purchased for use in online communities or online games. They have no intrinsic value and are intangible by definition....

  and services with one another. Second Life is intended for people aged 16 and over, and as of 2011 has about one million active users.

Built into the software is a three-dimensional modeling
3D modeling
In 3D computer graphics, 3D modeling is the process of developing a mathematical representation of any three-dimensional surface of object via specialized software. The product is called a 3D model...

 tool based around simple geometric shapes that allows residents to build virtual objects.