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.
The following is a list of some of the most stable MMOs on the market. They have healthy fanbases and significant developer support and are likely to survive and thrive for many years to come. Star Trek: Online. MMOs based on famous franchises can be an iffy proposition.