Wikipedia
Galaxiki is a web-based, free content virtual community web 2.0 project. It consists of a virtual galaxy with over a million stars and solar systems that can be explored using a 2-dimensional map. Each star, each planet and each moon represents one wiki page, the idea behind the project is that Galaxiki site members, also called Galaxicians, can edit those pages and write fictional histories about them.
Galaxiki's name is a portmanteau of the words galaxy and wiki (a type of collaborative website).
The Galaxiki rules say that real world physics should be respected, but it also allows some popular exceptions known from most science fiction novels, such as traveling faster than light or using paranormal powers for example. This also implies that species inside the Galaxiki world can meet (at least if their solar systems are in a closer range), which is a challenge for Galaxicians as they have to make sure to eliminate inconsistencies. Science fiction stories on Galaxiki are published by default under the GNU Free Documentation License.
Galaxiki membership, editing solar systems and using all other site features is free. To finance the project, solar systems can be "freed", which means that Galaxicians can make solar systems writable by making a small donation to the project. It is also possible to "purchase" individual solar systems to make their related wiki pages read-only for all other site members. There is a dedicated page for sponsors or advertisers too, but the project itself states that there shall be only an absolute minimum of advertising.
Most solar systems are currently still locked, but new solar systems are open automatically for the community every day. When a Galaxician "frees" a solar system he/she can decide if the system shall become open for the entire community, or if the system shall become a private project. In this case it is also possible to dedicate the star or solar system to someone.
Galaxiki was launched as a prototype on March 12, 2007, it was officially launched on July 1, 2007. It was Linux Journal's ".org site of the week" on July 11, 2007, listed under "best websites in August 2007" on about.com on August 3, it was Yahoo's "Pick of the Day" on August 27 and it was one of the SEOmoz "Web 2.0 awards" winners in 2008.
In 2010 Galaxiki 2.0 was released, turning the site into a social network and introducing over 100 new features and enhancements. It now has over 5000 registered users ("Galaxicians") and there are more than 12000 solar systems open for the community or registered by individual users.