"Eclipse Phase is a pen & paper roleplaying game of post-apocalyptic transhuman conspiracy and horror.

An "eclipse phase" is the period between when a cell is infected by a virus and when the virus appears within the cell and transforms it. During this period, the cell does not appear to be infected, but it is.

Players take part in a cross-faction secret network dubbed Firewall that is dedicated to counteracting "existential risks" — threats to the existence of transhumanity, whether they be biowar plagues, self-replicating nanoswarms, nuclear proliferation, terrorists with WMDs, net-breaking computer attacks, rogue AIs, alien encounters, or anything else that could drive an already decimated transhumanity to extinction."

"The Eclipse Phase roleplaying game was released under a Creative Commons license; the text found on the Eclipse Phase website is licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. As stated on their website, the publishers encourage players and gamemasters to recreate, alter, and "remix" the material for non-commercial purposes. Further, copying and sharing the game's PDF version is legal."

 
http://www.eclipsephase.com/ 
http://en.wikipedia.org/wiki/Eclipse_Phase_(role-playing_game)