A virus is a microscopic organism that can replicate only inside the cells of a host organism. Most viruses are so tiny they are only observable with at least a conventional optical microscope.
Recognized by the Guiness Book of World Records as the MMO with the longest play time per player, and easily the oldest game on this list (launching four years ahead of World of Warcraft, way back in 2001), Runescape deserves mention because it's one of the most updated and popular games of any kind on the planet.
Only four humans have logged a continuous year or more in space on a single mission, and all of those missions involved the Russian Mir space station, said NASA spokesman Joshua Buck. The current record is held by Valery Polyakov, who spent 438 days in space between January 1994 and March 1995.