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.
Guiding Light (known as The Guiding Light before 1975) is an American television soap opera listed in Guinness World Records as the longest-running drama in television in American history, broadcast on CBS for 57 years from June 30, 1952, until September 18, 2009, preceded by a 19-year broadcast on radio.