Second Life

Second Life is an online virtual world developed by Linden Lab. It was launched on June 23, 2003. A number of free client programs, or Viewers, enable Second Life users to interact with each other through avatars (also called Residents). 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 and services with one another. Second Life is intended for people aged 16 and over, with the exception of 13-15 year old users restricted to the Second Life-region of a sponsoring institution (e.g. school).

Built into the software is a three-dimensional modeling tool based on simple geometric shapes that allows residents to build virtual objects. There is also a procedural scripting language, Linden Scripting Language, which can be used to add interactivity to objects. Sculpted prims (sculpties), mesh, textures for clothing or other objects, animations, and gestures can be created using external software and imported. The Second Life terms of service provide that users retain copyright for any content they create, and the server and client provide simple digital rights management functions. However, Linden Lab changed their terms of service in August 2013, to be able to use user-generated content for any purpose. The new terms of service prevents you from using 3rd-party textures from some specific texture services as these have pointed out explicitly.

Second Life is also released to the entire Singapore by May 2010.

History
In 1999, Philip Rosedale formed Linden Lab with the intention of developing computer hardware that would allow people to immerse themselves in a virtual world. In its earliest form, the company struggled to produce a commercial version of the hardware, known as "The Rig", which was realized in prototype form as a clunky steel contraption with computer monitors worn on shoulders. That vision changed into the software application Linden World, in which people participated in task-based games and socializing in a three-dimensional online environment. That effort would eventually transform into the better known, user-centered Second Life. Although he was familiar with the metaverse of Neal Stephenson's novel Snow Crash, Rosedale has said that his vision of virtual worlds predates that book, and that he conducted early virtual world experiments during his college years at the University of California San Diego, where he studied physics.

In 2005 and 2006, Second Life began to receive a lot of media traction, including a cover story on Business Week magazine featuring the virtual world and Second Life avatar Anshe Chung. By that time, Anshe Chung had become Second Life's poster child and symbol for the economic opportunities that the virtual world offers to its residents. At the same time, the service would see a period of exponential growth of its user base.

On December 11, 2007, Cory Ondrejka, who helped program Second Life, was forced to resign as chief technology officer.

In January 2008, residents spent a total of 28,274,505 hours "inworld", and, on average, 38,000 residents were logged in at any particular moment. The maximum concurrency (number of avatars inworld) recorded is 88,200 in the 1st qtr. 2009

On March 14, 2008, Rosedale announced plans to step down from his position as Linden Lab CEO and to become chairman of Linden Lab's board of directors. Rosedale announced Mark Kingdon as the new CEO effective May 15, 2008. In 2010, Kingdon was replaced by Rosedale, who took over as Interim CEO. After four months though, Rosedale abruptly stepped down from the Interim CEO position. It was announced in October 2010, that Bob Komin, Linden Lab's chief financial officer and chief operating officer, will take over the CEO job for the immediate future.

In 2008, Second Life was honored at the 59th Annual Technology & Engineering Emmy Awards for advancing the development of online sites with user-generated content. Rosedale accepted the award.

In May 2009, concurrent users averaged about 62,000. As of May 2010, concurrent users averaged about 54,000. The perceived decline in concurrent users over this time correlates precisely with new policies implemented by Linden Lab reducing the number of bots and campers.

In June 2010, Linden Lab announced layoffs of 30% of its workforce.

In November 2010, 21.3 million accounts were registered, although the company has not made public figures for actual long-term consistent usage. However, Wagner James Au, who blogs and writes about Second Life, said in April 2013 that he had it on "good authority" that "Second Life's actual active userbase is about 600,000"

10th anniversary
June 2013 marked Second Life's 10th anniversary where users held parties, dances, live music, DJ events and celebrations. The SL10B community held the celebrations from June 16–29, 2013 with the main event on June 23, 2013, when Second Life celebrated its 10th anniversary. The event included exhibitions, performances, live music and more. In the welcome areas there were showcases including the Avatar Central, History Walk and the time capsules. There was also Bear Island on the east side of the map and the Corn Field on the west side of the map. There was free gear and apparel at the vendors throughout the area. There were special limited items on the Second Life Marketplace that coincided with SL10B, including a special SL10B avatar. On June 3, 2013, a Youtube video was uploaded of an interview featuring Rod Humble, CEO of Linden Lab. There were also events and parties held elsewhere on the Second Life grid. Over the last 10 years, 36 million accounts were created, US$3.6 billion was spent on virtual assets and the equivalent total time users spent on SL is 217,266 years. Today, more than 1 million people visit Second Life monthly. Games, events and Adventure/fantasty dominate the Destination guide. An average of about 400,000 new registrations are created monthly, 1.2 million daily transactions were conducted for virtual assets. 2.1 million user-created virtual assets are for sale, with the most purchased are women's hairstyles, and Second Life landmass is nearly 700 square miles (slightly over 1810 square kilometres).

Classification
During a 2001 meeting with investors, Rosedale noticed that the participants were particularly responsive to the collaborative, creative potential of Second Life. As a result, the initial objective-driven, gaming focus of Second Life was shifted to a more user-created, community-driven experience.

Second Life's status as a virtual world, a computer game, or a talker, is frequently debated. Unlike a traditional computer game, Second Life does not have a designated objective, nor traditional game play mechanics or rules. It can also be argued that Second Life is a multi-user virtual world, because the virtual world is centered around interaction between multiple users. As it does not have any stipulated goals, it is irrelevant to talk about winning or losing in relation to Second Life. Likewise, unlike a traditional talker, Second Life contains an extensive world that can be explored and interacted with, and it can be used purely as a creative tool set if the user so chooses.

Second Life used to offer two main grids: one for adults (18+) and one for teens. In August 2010, Linden Lab closed the teen grid due to operating costs. Since then, users aged 16 and over can sign up for a free account. Other limited accounts are available for educators who use Second Life with younger students.

There are three activity-based classifications, called "Ratings," for sims in Second Life:
 * General (formerly "PG"—no extreme violence or nudity)
 * Moderate (formerly "Mature"—some violence, swearing, adult situations, some nudity)
 * Adult (may contain overt sexual activity, nudity, and violence)

Residents and avatars
There is no charge for creating a Second Life account or for making use of the world for any period of time. Linden Lab reserves the right to charge for the creation of large numbers of multiple accounts for a single person (5 per household, 2 per 24 hours) but at present does not do so. A Premium membership (US$9.95 monthly, US$22.50 quarterly, or US$72 annually) extends access to an increased level of technical support, and also pays an automatic stipend of L$300/week into the member's avatar account, and after 45 days that resident will receive a L$700 bonus, making it L$1,000 for that week. This amount has decreased since the original stipend of L$500, which is still paid to older accounts. Certain accounts created during an earlier period may receive L$400. This stipend, if changed into USD, means that the actual cost for the benefit of extended tech support for an annual payment of US$72 is only about US$14, depending on the currency exchange rates. However, the vast majority of casual users of Second Life do not upgrade beyond the free "basic" account.

Avatars may take any form users choose (human, animal, vegetable, mineral, or a combination thereof) or residents may choose to resemble themselves as they are in real life. They may choose even more abstract forms, given that almost every aspect of an avatar is fully customizable. Second Life Culture consists of many activities and behaviors that are also present in real life. A single resident account may have only one avatar at a time, although the appearance of this avatar can change between as many different forms as the Resident wishes. Avatar forms, like almost everything else in Second Life, can be either created by the user, or bought pre-made. A single person may also have multiple accounts, and thus appear to be multiple Residents (a person's multiple accounts are referred to as alts).

Avatars can travel via walking, running, vehicular access, flying or teleportation. Because Second Life is such a vast virtual world, teleportation is used when avatars wish to travel instantly and efficiently. Once they reach their destination, they may travel in more conventional means at various speeds.

Avatars can communicate via local chat, group chat, global instant messaging (known as IM), and voice (public, private and group). Chatting is used for localized public conversations between two or more avatars, and is visible to any avatar within a given distance. IMs are used for private conversations, either between two avatars, or among the members of a group, or even between objects and avatars. Unlike chatting, IM communication does not depend on the participants being within a certain distance of each other. As of version 1.18.1.2, voice chat, both local and IM, was also available on both the main grid and teen grid. Instant messages may optionally be sent to a Resident's email when the Resident is logged off, although message length is limited to 4096 bytes.

Economy
Second Life has an internal economy and internal currency, the Linden dollar (L$). L$ can be used to buy, sell, rent or trade land or goods and services with other users. Virtual goods include buildings, vehicles, devices of all kinds, animations, clothing, skin, hair, jewelry, flora and fauna, and works of art. Services include "camping", wage labor, business management, entertainment, and custom content creation (which can be broken up into the following six categories: building, texturing, scripting, animating, art direction, and the position of producer/project funder). L$ can be purchased using US dollars and other currencies on the LindeX exchange provided by Linden Lab, independent brokers or other resident users. Money obtained from currency sales is most commonly used to pay Second Life's own subscription and tier fees; only a relatively small number of users earn large amounts of money from the world. According to figures published by Linden Lab, about 64,000 users made a profit in Second Life in February 2009, of whom 38,524 made less than US$10, while 233 made more than US$5000. Profits are derived from selling virtual goods, renting land, and a broad range of services.

The "Linden" can be exchanged for US dollars or other currencies on market-based currency exchanges. Linden Lab reports that the Second Life economy generated US$3,596,674 in economic activity during the month of September 2005, and as of September 2006 Second Life was reported to have a GDP of $64 Million. In 2009, the total size of the Second Life economy grew 65% to US$567 million, about 25% of the entire U.S. virtual goods market. Gross resident earnings are US$55 million in 2009 – 11% growth over 2008. In March 2009, it was revealed that there existed a few Second Life entrepreneurs who had grossed in excess of US$1 million per year, most notably Ailin Graef, who is more well known as her avatar, Anshe Chung.

Alternative user interfaces
Since the Second Life viewer was made open-source, a number of accessibility solutions have been developed (listed in chronological order):
 * A modification of the Second Life viewer has been developed that allows users who are visually impaired to navigate their avatar using force feedback. Different object types are distinguished through different vibration frequencies.
 * TextSL is a web-based client developed by the University of Nevada that allows users who are visually impaired to access Second Life using built in speech synthesis. TextSL allows users who are visually impaired to navigate, communicate with avatars and interact with objects using a command based interface inspired by the Zork adventure game. This web interface is also accessible using a smartphone.
 * IBM's Human Ability and Accessibility Center, with the IBM Virtual Universe Community, developed a Web based interface for Second Life that can be accessed with a screen reader. This client provides basic navigation, communication, and perception functions using hotkeys.
 * Max, The Virtual Guidedog, developed by Virtual Helping Hands, offers a virtual guide dog object that can be "worn" by a user's avatar. The guidedog provides a number of functions such as navigation and querying the environment through a chat-like interface. Feedback is provided using synthetic speech.
 * METAbolt is an open source text client developed by the METAbolt Development Team which is fully accessible and also compatible with accessibility client applications (Microsoft platforms only) such as JAWS.
 * SLTalker is a talker-like (text-based) interface for Second Life. The user can connect to it using telnet-ssl or any talker or MUD client that supports SSL secure connections.

A study showed that one of the biggest barriers to making Second Life accessible to visually impaired users is its apparent lack of metadata, such as names and descriptions, for virtual world objects. This is a similar problem for the accessibility of the web, where images may lack alternative tags. The study found that 32% of the objects in Second Life are simply named "object", and up to 40% lack accurate names.

Language localization
In 2007, Brazil became the first country to have its own independently run portal to Second Life, operated by an intermediary—although the actual Second Life grid accessed through the Brazilian portal is the same as that used by the rest of the worldwide customer base. The portal, called "Mainland Brazil", is run by Kaizen Games, making Kaizen the first partner in Linden's "Global Provider Program". In October 2007, Linden Lab signed a second "Global Provider Program" with T-Entertainment Co., LTD., Seoul, South Korea and T-Entertainment's portal called "SERA Korea" serves as a gateway to Second Life Grid. Previously, starting in late 2005, Linden Lab had opened and run their own welcome area portals and regions for German, Korean and Japanese language speakers.

Public chat within the world supports many written languages and character sets, providing the ability for people to chat in their native languages. Several resident-created translation devices provide machine translation of public chat (using various online translation services), allowing for communication between residents who speak different languages. Most versions of the viewer have language translation built into them. Within the current generation of the Second Life viewer, Linden Labs has incorporated language translation from Google.

Land ownership
Premium membership allows the Resident to own land, with the first 512 m² (of main land owned by a holder of a Premium account) free of the usual monthly land use fee (referred to by residents as tier, because it is charged in tiers). There is no upper limit on tier; at the highest level, the user pays US$295 for their first 65,536 m². Any land must first be purchased from either Linden Lab or a private seller.

There are four types of land regions; mainland, private region, homestead, and openspace. A region comprises an area of 65536 m² in area, being 256 meters on each side. Mainland regions form one continuous land mass, while private regions are islands. Openspace regions may be either mainland or private, but have lower prim limits and traffic use levels than mainland regions. The owners of a private region enjoy access to some additional controls that are not available to mainland owners; for example, they have a greater ability to alter the shape of the land. Residents must own a region (either mainland or private) to qualify for purchasing an openspace region.

Linden Lab usually sells only complete 65536 m² regions at auction (although smaller parcels are auctioned on occasion, typically land parcels abandoned by users who have left). Once Residents buy land they may resell it freely and use it for any purpose that it is not prohibited by the Second Life terms of service.

Residents may also choose to purchase, or rent, land from another Resident (a Resident landlord) rather than from Linden Lab. On a private region, the built-in land selling controls allow the landlord to sell land in the region to another Resident while still retaining some control. Residents purchasing, or renting, land from any other party than Linden Lab are not required to hold a Premium membership nor to necessarily pay a tier fee, although typically the landlord will require some form of upfront or monthly fee to compensate them for their liability to pay the land use fee charged by Linden Lab. However Linden Lab acknowledges only the landlord as the owner of the land, and will not intervene in disputes between Residents. This means, for example, that a landlord can withdraw a Resident's land from availability, without refunding their money, and Linden Lab will not arbitrate in the dispute unless it is a clear-cut matter of 'land fraud'. Users can report such matters to Linden Lab if they occur and they will look into it.

Land types
For mainland fees, the fee determines only the area of land available; the number of prims available is determined by the land itself. Some mainland regions offer more prims in the same land area. For non-mainland fees, the fee sets both the land area and the prim count.

There are only a few grandfathered "high prim" islands, which are otherwise identical to regular islands but have a higher limit set in the server software. They can be resold but are rarely available for purchase.

Grids
The grid is made of regions, each a square of side 256 (= 28) meters. Regions without servers appear as deep sea and cannot be entered and cannot be flown over, but regions with servers can be seen across regions without servers. But, a user's "point of view" can enter a region without a server.

The full grid is a square with sides of 228 meters, for a total area of 72×109 km2, roughly 140 times the Earth's surface area. It supports up to 240 (more than 1012) regions. But all or most regions with servers are in the extreme northwest corner of this vast theoretical area. As of April 2011, 2,059.86 km2 of this area was allocated to 31431 actual regions, a little smaller than the country of Luxembourg.

Before January 20, 2011, there appeared to be two age-differentiated grids; they were actually two rigidly-isolated parts of one grid. When it originally started, only people 18 years and over could join. However, after much controversy about underage people joining, Linden Lab created the Teen Grid, which was for those ages 13–17. When teens turned 18, providing documentation verifying their age, they would be transferred to the Main Grid. Linden Lab received controversy for the lack of integration between teens and adults. Some parents protested that they could not be on the grid together with their teenage children, and companies could not market to both teens and adults in SL even though their products had universal appeal. This grid merge was widely supported by teen grid residents, but some also opposed it. Some Linden Lab employees were also in favor of merging the grids, most notably Blue Linden, former teen grid manager.

Since June 9, 2012, Second Life has revised its age verification process; minors are now forbidden from the game. Users under 18 years of age are not allowed in Second Life, and if anyone is under reasonable suspicion of being underage, their account may be suspended until their age can be verified. Whereas before, one could present legitimate documentation to prove that they had turned of age, mature areas now only show a warning message and rely on the user's own judgement and consent to proceed. 

Some regions of the grid are intended to recreate famous places or cities that exist in real life or fiction.

Technology
Second Life comprises the viewer (also known as the client) executing on the user's personal computer, and several thousand servers operated by Linden Lab.

Client
Linden Lab provides official viewers for Microsoft Windows, Mac OS X, and most distributions of Linux. The viewer renders 3D graphics using OpenGL technology. The viewer source code was released under the GPL in 2007 and moved to the LGPL in 2010.

There are now several mature third party viewer projects that contain features not available in the Linden Lab 'Official' client, target other platforms or cater to specialist & accessibility needs. The main focus of third party development is exploring new ideas and working with Linden Lab to deliver new functionality.

An independent project, libopenmetaverse, offers a function library for interacting with Second Life servers. libopenmetaverse has been used to create non-graphic third party viewers.

There are several Alternate Viewers published by Linden Lab used for software testing by volunteers for early access to upcoming projects. Some of these clients only function on the "beta grid" consisting of a limited number of regions running various releases of unstable test server code.

Server
Each full region (an area of 256×256 meters) in the Second Life "grid" runs on a single dedicated core of a multi-core server. Homestead regions share 3 regions per core and Openspace Regions share 4 regions per core, running proprietary software on Debian Linux. These servers run scripts in the region, as well as providing communication between avatars and objects present in the region.

Every item in the Second Life universe is referred to as an asset. This includes the shapes of the 3D objects known as primitives, the digital images referred to as textures that decorate primitives, digitized audio clips, avatar shape and appearance, avatar skin textures, LSL scripts, information written on notecards, and so on. Each asset is referenced with a universally unique identifier or UUID.

Assets are stored on Isilon Systems storage clusters, comprising all data that has ever been created by anyone who has been in the SL world. Infrequently used assets are offloaded to S3 bulk storage. , the total storage was estimated to consume 100 terabytes of server capacity. The asset servers function independently of the region simulators, though the region simulators request object data from the asset servers when a new object loads into the simulator.

Each server instance runs a physics simulation to manage the collisions and interactions of all objects in that region. Objects can be nonphysical and non-moving, or actively physical and movable. Complex shapes may be linked together in groups of up to 255 separate primitives. Additionally, each player's avatar is treated as a physical object so that it may interact with physical objects in the world. , Second Life simulators use the Havok 4 physics engine for all in-world dynamics. This engine is capable of simulating thousands of physical objects at once.

Linden Lab pursues the use of open standards technologies, and uses free and open source software such as Apache, MySQL, Squid and Linux. The plan is to move everything to open standards by standardizing the Second Life protocol. Cory Ondrejka, former CTO of Second Life, has stated that a while after everything has been standardized, both the client and the server will be released as free and open source software.

OpenSimulator
In January 2007, OpenSimulator was founded as an open source simulator project. The aim of this project is to develop a full open source server software for Second Life clients. OpenSIM is BSD Licensed and it is written in C# and can run under Mono environment. In 2008 there were some alternative grids which are using OpenSimulator.

Virtual technology
The graphics, the Linden Scripting Language, and the Havok physics engine enable the simulation of various real or imagined machines and devices. There are many light houses, some with detailed Fresnel lenses. Steam punk buoyant airships are also common. There are combat weapons systems. A large part of the Linden Scripting Language Guide describes the features available for modeling vehicles. Popular uses of this include cars, boats, motorcycles and airplanes. Manned vehicles have advantages, but there can also be autonomous or remotely controlled vehicles. A major obstacle is region (sim) border crossings, which unlike cell phone handoffs, are a problem for users, even at walking speed. Recent work by Linden Lab has greatly improved this, and if the user in question has few resources assigned to him or her, the crossing can be almost seamless.

SL "physics" (based on computer game physics) consists mostly of avoidance of interpenetration of avatars and other "physical" objects with other objects, "physical" or not; but for "physical" objects, most importantly vehicles, there is an approximation of real world motion. Avatars can "sit" on vehicles and their users can control them. The scripting language includes many system call specialized for vehicles, to define their movement and control, but the correspondence to real world motion is not quantitatively defined. SL vehicles typically act like real world vehicles only in superficial ways. To some extent, the differences are needed to deal with the sim crossing problem (including the oldest known bug in the SL software), the time step (at best about 1/40 sec.) the Internet communication latency (lag), and so forth. For some types of moving objects, a fairly high degree of realism is possible within these limits, but, with the provided system calls, simpler motions are easier to script.

Education
Second Life is used as a platform for education by many institutions, such as colleges, universities, libraries and government entities.

Since 2008, the University of San Martin de Porres of Peru has been developing Second Life prototypes of Peruvian archeological buildings, and training teachers for this new paradigm of education.

Arts
Second Life residents express themselves creatively through virtual world adaptations of art exhibits, live music, live theater and machinima, as well as other art forms.

Science
Second Life is used for scientific research, collaboration, and data visualization. Examples include SciLands, American Chemical Society's ACS Island, Genome, Virginia Tech's SLATE, and Nature Publishing Group's Elucian Islands Village.

Work solutions
Second Life gives companies the option to create virtual workplaces to allow employees to virtually meet, hold events, practice any kind of corporate communications, conduct training sessions in 3D immersive virtual learning environment, simulate business processes, and prototype new products.

Religion
Religious organizations have also begun to open virtual meeting places within Second Life. In early 2007, LifeChurch.tv, a Christian church headquartered in Edmond, Oklahoma, and with eleven campuses in the USA, created "Experience Island" and opened its twelfth campus in Second Life. The church reported "We find that this creates a less-threatening environment where people are much more willing to explore and discuss spiritual things". In July 2007, an Anglican cathedral was established in Second Life; Mark Brown, the head of the group that built the cathedral, noted that there is "an interest in what I call depth, and a moving away from light, fluffy Christianity".

The First Unitarian Universalist Congregation of Second Life (www.fuucsl.org) was established in 2006. Services have been held regularly making the FUUCSL Congregation one of the longest-running active congregations in Second Life.

The Egyptian-owned news website Islam Online has purchased land in Second Life to allow Muslims and non-Muslims alike to perform the ritual of Hajj in virtual reality form, obtaining experience before actually making the pilgrimage to Mecca in person.

Second Life also offers several groups that cater to the needs and interests of Humanists, atheists, agnostics, and freethinkers. One of the most active groups is SL Humanism which has been holding weekly discussion meetings inside Second Life every Sunday since 2006.

Embassies
The Maldives was the first country to open an embassy in Second Life. The Maldives' embassy is located on Second Life's "Diplomacy Island", where visitors will be able to talk face-to-face with a computer-generated ambassador about visas, trade and other issues. "Diplomacy Island" also hosts Diplomatic Museum and Diplomatic Academy. The Island is established by DiploFoundation as part of the Virtual Diplomacy Project.

In May 2007 Sweden became the second country to open an embassy in Second Life. Run by the Swedish Institute, the embassy serves to promote Sweden's image and culture, rather than providing any real or virtual services. The Swedish Minister for Foreign Affairs, Carl Bildt, stated on his blog that he hoped he would get an invitation to the grand opening.

In September 2007, Publicis Group announced the project of creating a Serbia island as a part of a project Serbia Under Construction. The project is officially supported by Ministry of Diaspora of Serbian Government. It was stated that the island will feature Nikola Tesla Museum, Guča trumpet festival and Exit festival. It was also planned on opening a virtual info terminals of Ministry of Diaspora.

On Tuesday December 4, 2007, Estonia became the third country to open an embassy in Second Life. In September 2007, Colombia and Serbia opened embassies. As of 2008, Macedonia and the Philippines have opened embassies in the "Diplomatic Island" of Second Life. In 2008, Albania opened an Embassy in the Nova Bay location. SL Israel was inaugurated in January 2008 in an effort to showcase Israel to a global audience, though without any connection to official Israeli diplomatic channels.

Malta and Djibouti are also planning to open virtual missions in Second Life.

Competitive entertainment
A wide variety of recreational activities, both competitive and non-competitive, take place on the Second Life Grid, including both traditional sports and video game-like scenarios.

Relationships
Relationships are common in Second Life, including some couples who have married online. The social engagement offered by the online environment helps those who might be socially isolated. In addition, sex is often encountered. However, to access the adult sections requires age verification. There is also a large BDSM community.

Second Life relationships have been taken from virtual online relationships into personal, real-world relationships. Booperkit Moseley and Shukran Fahid were possibly the first couple to meet in Second Life and then marry in real life. Booperkit travelled to America to meet Shukran and he returned to England with her after one week. They met in 2005 and were married in 2006. They currently live in the UK with 4-year-old twin sons. Some couples meet online, form friendships, and eventually move to finding one another in the real world. Some even have their weddings on Second Life, as well as in a real-world setting.

Role-playing
There are many destinations within Second Life which are dedicated to those who enjoy role-playing. Some of these are targeted for adults, however there are also many which focus on other themes, such as fantasy, history, science fiction or other subjects. Many of these types of worlds have very specific sets of rules that each avatar who visits is expected to follow. Such rules can include things such as a dress code, a code of behavior, and world guidelines. If these rules are not followed, the avatar can be booted from the world by a game administrator. One example of one of these role-playing worlds is "The Realm of Valahari". This particular world takes place in a fantasy medieval setting. In order to exist within that world, your avatar must be dressed in fantasy or medieval attire. In case your avatar does not already own such clothing, the world provides clothing shops for you in an area which you visit before you actually enter the world. However, none of these clothing shops provide free items; all of them cost Linden Dollars (L$). Within the world, everyone is also expected to maintain the role-playing atmosphere. Anyone who is using "regular" or "everyday" language tends to be frowned upon and seen as an outsider by the other members of the Realm. "Regular" language is to be kept in private chat windows, so that the fantasy/medieval atmosphere is not polluted by it. Another example is the historical role playing sim called The 1920s Berlin project where they have many of the same rules but here visitors experience a more history based immersive experience. Other sims may incorporate rules that have less to do with thematic realism, and more to do with adhering to community guidelines. For instance, one rule that is commonly seen is the prohibition or restriction of underage avatars in role-playing sims that feature adult content; these rules are separate from Linden Labs' sim restrictions, as they restrict underage characters played by adult players.

Role-play sims are usually either non-metered, script metered, or use the sim server health meter. In non-metered combat sims, all fighting is done through paragraph RP, usually with the assistance of role-play dice, or the players may determine the outcome they desire privately in IMs, and then role-play out the ending in character using public chat. In metered combat sims, players carry weapons that are scripted to act in conjunction with the meter. Players are then able to fight using these weapons and/or any capabilities built into the meter itself until one player's health expires and they "die". They are either resurrected by another player, automatically revive after a certain period of time, or are returned to their home sim position with their full health restored. Some metered combat sims allow for non-metered combat to be used under certain circumstances; in these cases, the method of combat used depends upon preferences of the participants in a given scene.

The integration between content purchases and provision of role-playing content has occasionally caused controversy in Second Life. Some examples include:
 * a user may use real money, transferred via L$, to purchase clothing or items for a role-playing area, only to be banned from that area and have the value of those items wiped out;
 * "Intrusive role-play", in which avatars role-play in a disruptive way in areas that are not intended for role-playing, has caused problems in the past. Examples include avatars dressing as police officers and claiming to have authority over areas that have nothing to do with them, or a previously sold system which allowed avatars to play vampires and "bite" any other avatar to "steal their soul"; some new users were convinced this would have a permanent effect on their avatar and even paid to purchase role-playing items to restore their soul, unaware that the effect was entirely irrelevant if the player did not wish to participate in the vampire role-play;
 * the range of avatar costumes and items available is much greater than the range of role-play areas and the range of playable social roles, meaning that users may purchase items not realizing that the role they are advertised as providing cannot exist. This also applies to weapons, which are regulated differently across different role-playing sims or chains of sims;
 * some metered combat systems allow affiliated merchants to develop weapons using their system's API. This allows those merchants to develop and sell weapons that deal additional damage or have other mechanical effects on combat; these weapons are often more expensive than similar weapons that do not incorporate these enhancements. Depending upon the specifics of the API, a merchant's weapons may end up being more powerful than the combat system's developer intended. In these cases, the merchant's API privileges may be revoked, resulting in both the developer's new and pre-existing weapons losing their special abilities. This eliminates much of the value of the weapons, which have already been purchased by users using L$.

Criticism and controversy
A number of difficult issues have arisen around Second Life. Issues range from the technical (budgeting of server resources), to moral (pornography), to legal (legal position of the Linden Dollar, Bragg v. Linden Lab). Security issues have also been a concern.

Regulation
In the past, large portions of the Second Life economy consisted of businesses that are now regulated or banned. Changes to Second Life's Terms of Service in this regard have largely had the purpose of bringing activity within Second Life into compliance with various international laws, even though the person running the business may be in full compliance with the law in their own country. Linden Lab offer no compensation for businesses that are damaged or destroyed by these rule changes, which can render significant expenditure or effort worthless.

On July 26, 2007, Linden Lab announced a ban on in-world gambling, in fear that new regulations on Internet gambling could affect Linden Lab if it was permitted to continue. The ban was immediately met with in-world protests.

In August 2007, a $750,000 in-world bank called Ginko Financial collapsed due to a bank run triggered by Linden Lab's ban on gambling, which halved the size of the Second Life economy. The aftershocks of this collapse caused severe liquidity problems for other virtual "banks", which critics had long asserted were scams. On Tuesday, January 8, 2008 Linden Lab announced the upcoming prohibition of payment of fixed interest on cash deposits in unregulated banking activities in-world. All banks without real-world charters closed or converted to virtual joint stock companies by January 22, 2008. After the ban, a few companies continue to offer non-interest bearing deposit accounts to residents, such as the e-commerce site XStreet, which had already adopted a zero-interest policy 3 months before the LL interest ban.

Technical issues
Due to Second Life's rapid growth rate, it has suffered from difficulties related to system instability. These include increased system latency, and intermittent client crashes. However, some faults are caused by the system's use of an "asset server" cluster, on which the actual data governing objects is stored separately from the areas of the world and the avatars that use those objects. The communication between the main servers and the asset cluster appears to constitute a bottleneck which frequently causes problems. Typically, when asset server downtime is announced, users are advised not to build, manipulate objects, or engage in business, leaving them with little to do but chat and generally reducing confidence in all businesses on the grid.

A more disturbing fact, believed to be caused by the same issue, is "inventory loss"  in which items in a user's inventory, including those which have been paid for, can disappear without warning or permanently enter a state where they will fail to appear in-world when requested (giving an "object missing from database" error). Linden Lab offers no compensation for items that are lost in this way, although a policy change instituted in 2008 allows accounts to file support tickets when inventory loss occurs. Many in-world businesses will attempt to compensate for this or restore items, although they are under no obligation to do so and not all are able to do so. A recent change in how the company handles items which have "lost their parent directory" means that inventory loss is much less of a problem and resolves faster than in recent years. "Loss to recovery times" have gone from months (or never) to hours or a day or two for the majority of users, but inventory loss does still exist.

Second Life functions by streaming all data to the user live over the Internet with minimal local caching of frequently used data. The user is expected to have a minimum of 300kbit/s of Internet bandwidth for basic functionality, with 1Mbit/s providing better performance. Due to the proprietary communications protocols, it is not possible to use a network proxy/caching service to reduce network load when many people are all using the same location, such as when used for group activities in a school or business.

Needs to hold a meeting of more people than can be supported by a region's server, has prompted a behavior called "four-cornering", i.e. meeting where four regions with servers all meet; this is unwelcome, as it tends to put excessive load on the system sending object and texturing information and inter-user messages between those four regions' servers.

In some cases the Lindens told people who had months (or years) of critically bad simulator performance that they changed the simulator server it fixed the problem permanently. This proves the existence of invisible host classes that are persistent/permanent despite repeated server reboots, can be permanently changed by the Lindens for a specific land, are invisible to the user in all circumstances aside from the extreme performance difference, and have identical land fees being paid to Linden Lab. This has been nicknamed the 'host lottery problem'. 

Fraud and intellectual property protection
Although Second Life's client and server incorporate Digital Rights Management technology, the visual data of an object must ultimately be sent to the client in order for it to be drawn; thus unofficial third-party clients can bypass them. One such program, CopyBot, was developed in 2006 as a debugging tool to enable objects to be backed up, but was immediately hijacked for use in copying objects; additionally, programs that generally attack client-side processing of data, such as GLIntercept, can copy certain pieces of data. Such use is prohibited under the Second Life TOS and could be prosecuted under the DMCA.

Linden Lab may ban a user who is observed using CopyBot or a similar client, but it will not ban a user simply for uploading or even selling copied content; in this case, Linden Lab's enforcement of intellectual property law is limited to that required by the "safe harbor" provisions of the Digital Millennium Copyright Act, which requires filing a real-life lawsuit. Although a few high-profile businesses in Second Life have filed such lawsuits,    none of the cases filed to date have gone to trial, and most have been dismissed pursuant to a settlement agreement reached between the parties. Overall, the majority of businesses in Second Life do not make enough money for a lawsuit to be worthwhile, or due to real-life work commitments, they cannot devote enough time to complete one. As a result, many Second Life businesses and their intellectual property remains effectively unprotected. Another case where settlement and dismissal was gained may be found in the matter of Eros, LLC v. Linden Research, Inc. As of October 7, 2010, the case was transferred to private mediation and the plaintiffs filed for dismissal of charges on March 15, 2011.

There have also been issues with the use of false DMCA takedown notices. Once a DMCA takedown notice is served, reversing it requires an individual to expose his personal information to the filer (filing a notice does not require this); for the penalty of perjury to be enacted, a lawsuit is required (anything less, the false DMCA claimer can just claim it from a different account every week causing legitimate business unlimited losses). In addition, the technical process of removal and re-instatement of content on Second Life is subject to failure which can result in content becoming unusable to its owner. This does not effectively prevent content theft; a thief who is subject to a DMCA takedown notice will not challenge it, but will simply create a new account and re-upload the content, often releasing it with all permissions available to maximize propagation out of spite.

Most users in the world as paying, private individuals are, likewise, effectively unprotected. Common forms of fraud taking place in-world include bogus investment and pyramid schemes, fake or hacked vendors, and failure to honor land rental agreements. A group of virtual landowners online have filed a class action lawsuit against the company, claiming the company broke the law when it rescinded their ownership rights. The plaintiffs say a change in the terms of service forced them to either accept new terms that rescinded their virtual property ownership rights, or else be locked out of the site.

Third-party viewers
The Emerald client, developed by a group of users based on an open-source branch of the Viewer, Snowglobe, became extremely popular and was used by a large proportion of the user base. The authors of the Emerald client were strongly believed to have gained influence over Linden Lab, to the point that two programmers fired from Linden Lab were immediately hired by Emerald, one of whom is still working with Phoenix/Firestorm today. Several groups alleged that the Emerald viewer contained trojan code which tracked user details and demographics in a way that the developers could later recover. While this data collecting was not done within the viewer, but done with inworld logging scripts, one of these groups was banned from Second Life by Linden Lab after publishing their discovery. Shortly afterward, it was discovered that one of the members of the Emerald team had attempted to use the viewer to DDOS another website. In response, Linden Lab revoked Emerald's third party viewer approval and permanently banned several of Emerald's developers. Many remaining Emerald developers left to work on a new viewer project, Phoenix, which started off where Emerald ended, but doesn't contain any malicious code. It is now the most popular viewer used by Second Life residents. Phoenix is no longer being worked on and its popularity will soon to be surpassed by Firestorm, another viewer made by the same group as Phoenix, but based on Linden Lab's newer codebase and contains new features Linden Lab has developed more recently.

Due to what happened with Emerald, Linden Lab instituted a Third Party Viewer Directory, which lists viewers that have submitted for review and have been approved by Linden Lab as not containing any malicious intent. They also outlined a new Third Party Viewer Policy, which can be found here: http://secondlife.com/corporate/tpv.php

For a listing of third party viewers that Linden Lab has approved, see http://wiki.secondlife.com/wiki/Third_Party_Viewer_Directory (listing is by stability of the viewer to promote competition in making the TPV as stable as possible).

Ban of Woodbury University


Linden Lab has twice, in 2007 and 2010, banned a California educational institution, Woodbury University, from having a representation within Second Life. On April 20, 2010, four simulators belonging to the university were deleted and the accounts of several students and professors terminated, according to The Chronicle of Higher Education. Professor Edward Clift, Dean of the School of Media, Culture and Design at Woodbury University, told The Chronicle of Higher Education that their campus "was a living, breathing campus in Second Life," that included educational spaces designed mostly by students, including a mock representation of the former Soviet Union and a replica of the Berlin Wall. According to Professor Clift, the virtual campus did not "conform to what Linden Lab wanted a campus to be."

A virtual organisation called INF (INF-Life) also supported the actions against Woodbury.

The article in The Chronicle of Higher Education concluded with, "Meanwhile, many people in Second Life expressed on blogs that they were glad to see the virtual campus go, arguing that it had been a haven for troublemakers in the virtual world."

References in popular culture
Since its debut in 2003, Second Life has been referenced by various popular culture media, including literature, television, film, and music.

In an episode of The Office, Jim creates a Second Life character to offset Dwight.

In 2007, the game makes an appearance in two fourth season episodes ("Down the Rabbit Hole" and "DOA for a Day") of CSI: NY.

In an episode of The Suite Life on Deck, Woody gets addicted to "Better Life", a parody of Second Life.

The series True Life did an episode that involved Second Life. The episode called "True Life: I Have Another Life on the Web”, aired in 2008 and followed three people who have alter egos online that greatly differ from who they are in reality. Amy used Second Life and she had two avatars, or alter egos. The first is named Keiko, an avatar that resembles her, and her second alter ego is Mama Shepard, a 38 year old widow, who owns and operates a virtual bakery. Amy was completely involved in her virtual world. Ben Rosen, the producer of this True Life episode, explained that Second Life houses a lot of people obsessed with their “other lives” in this virtual world. With its own currency, job opportunities, and shopping options, Second Life allows for endless possibilities for avatars and endless opportunities for the people playing on Second Life.

Italian popstar Irene Grandi released a music video for her major chart hit "Bruci la città" in 2007 almost entirely filmed within Second Life featuring her own lifelike avatar.

Jonathan Lethem's 2009 novel Chronic City features a game called "Yet Another World", which closely resembles Second Life, as a major plot point in the second half of the story.

Additionally, the 2010 satirical graphic novel Other Lives by Peter Bagge features a fictional game, "Second World", that is closely based on Second Life.

Second Life is featured prominently in a scene from the 2010 movie Hot Tub Time Machine. The character Jacob is playing as his avatar Jacob Morlim in-world, and the scene shows several shots of Second Life gameplay.

In an episode of The Big Bang Theory, Sheldon Cooper asks one of his friends if they would like to play Second Life and go virtual swimming, since he does not like the water in real life.

"My Avatar and Me" 2010 Danish "documentary fantasy" by Bente Milton and Mikkel Stolt. A man enters Second Life to pursue his personal dreams and ambitions. His journey into cyberspace becomes a magic learning experience, which gradually opens the gates to a much larger reality. Starring Mikkel Stolt, features cameos by Long Now co-founder Danny Hillis and the Foundation’s Nevada site.

The German documentary "Login2Life" which aired first on public broadcasting station ZDF on October 17th 2011 portrays 7 people who have found an alternate home in Second Life and World Of Warcraft.