What is Orion's Arm? You don't know?
Well I'll tell you. Orion's Arm is a transhumanist space opera shared universe that attempts to predict what life will be like 10,000 years in the future. It uses hard science and concepts like the Singularity and Mind Uploading to create a vision of the future that, in short, is pretty cool. OA (as it is known) takes place in a setting where human colonization of other planets and stars had accelerated so much that inhabited space now encompasses everything within 7000 light-years. And ruling over many interstellar empires are vast, god-like AIs, 1035 times more intelligent than humans. And humans themselves have branched into collections of beings so diverse, one cannot tell that they are all descended from today's Homo Sapiens Sapiens. After 10,000 years of genetic engineering and technological process, in the OA universe, you can be anything.
Orion's Arm was created by M. Alan Kazlev and Donna Malcolm Hirsekorn. They have 3 Yahoo groups via which new stuff is submitted and is eventually put on the site. There are currently about 1300 people contributing to the project, and I'm proud to say that I am one of them!
Orion's Arm can be found at