Science Fiction

The Community
Includes a number of interstellar colony histories and some astronomically realistic star maps.
http://www.angelfire.com/realm2/comgalaxy/

Local Group
An extensively thought-out future history, illustrative glossary, and brief notes on the Boolean race. Emphasizes exploration and political intrigue.
http://www.cs.cmu.edu/~tpope/local-group/index.html

Lungfish Alpha
A science-surrealist world that doesn't so much blur the lines between genres as pave over them, Lungfish Alpha combines space opera, cyberpunk, and fantasy into a unique world.
http://groups.yahoo.com/group/Lungfishalpha/