Users have the option to own or rent land parcels in a variety of sizes - as in real life, some owners may zone their land to restrict certain activities, such as commercial development. The system is funded through a combination of account subscriptions and 'tier' (a form of land value tax). Second Life has over 8,268,883 registered users and 1,548,131 active users as of Jlogged-in users range from 20,000 to 60,000 at any one time. Third-party clients, most of them based on the (almost) open-source official client, are popular among users. The client connects to the Second Life Grid, a cluster of machines running the server software. Second Life is accessed with its client software, also known as a 'viewer'. Those aged 16 or over were transferred to the main grid, while those 15 or under had their accounts frozen until they reached 16. A teen version for those 13 to 17 was available until the end of 2010, when it was shut down. The 'main grid' is restricted to those 18 or over, as some regions contain strong violence or sexual content. The major form of short-distance transportation is flight, while transportation between areas is typically performed through teleportation both abilities are innate. Second Life is an online virtual world consisting of hundreds of interconnected large-scale areas populated by interactive avatars, whose players may choose to take any form they can create or purchase.
