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.
In 1998, Intamin built its first inverted roller coaster, which to this day is still the fastest complete circuit inverted roller coaster in the world. Volcano: The Blast Coaster, at Kings Dominion in Virginia, literally blew the Vekoma SLC design away. It features a linear induction motor launch from 0 to 70 out of the top of a 155-foot volcano.