This place is part of a land called “The Future”. This dome and most things in it are built by Henry Segerman.
Second Life is a online virtual world, with 40 thousand users logged in at any moment as of 2010-05. Basically, you operate a software that shows a interactive computer-generated 3D world much like video games, but everything in the “game” is constructed by the users themselves, and you can interact with other users, including chatting in text or voice, and buying and selling virtual land with real money. What people do inside Second Life is entirely up to them (as in real life). And, as it happens, what people do mostly in Second Life are pretty much what people do in real life. The major activities are: sex, shopping, socializing, dancing.
(notable differences is that in Second Life, there's no famine, war. (There are some politics (pertaining to Real Life politics, but also spontaneous in-world power struggle) and religion.) Since, after all, Second Life is a game and people don't die in it. There're no survival pressures.).
My mathematician friend Henry Segerman introduced me to 2nd life. (also because it appeared in Time Mag in 2006-12.)
Part of my interest in Second Life is to build geometric models. (See: Introduction to 3D Graphics Programing) I have for the past couple years sought for a software system where i can build 3D objects, with abilities to do interactive manipulation, such as moving a slider to change a parametric surface's parameter, interactive rotation , animations, and most of all, walk-thru in it as if it is a building (See: Geometry: Requirements for a Visualization System for 2020).
Second Life is not just the answer to my mathematical fantasies, but because of its Real-World nature, being run and build by real people, and with real money market of the virtual dollars it uses, is nothing but a technological revolution with great social impact. It is essentially the virtual-3D-world-wide-web dream of VRML envisioned around 1995.
Anshe Chung is famouly known for being the first to become a real world millionaire by selling entirely virtual items and virtual services inside Second Life. There are few others became wealthy thru sl. For more business aspects of sl, see: Second Life Product Market Value.
Addendum, 2007-01-21, 2007-03-20, 2008-10-21.
Note that Second Life is not the first “virtual world” (however that is defined), and, it has many competitors. (for a list: Virtual world)
When virtual world like Second Life becomes household activity as the internet is today, it will probably not be known as Second Life or run by one single company, but diverse companies with servers all over the world, where the different networks are all inter-connected. (This situation may be likened to The Internet in its early history (1980s-1995), telephone network, Instant Messaging networks, or today's social networks.
Today, there are 40k to 60k users online in Second Life at any given time. There are 32k regions. Almost all major US universities has a course or presence in Second Life. And, many tech corporations, such as IBM, AMD, etc has a presence. Even some country's government has a presence. See: Second Life Demographics 2009.