||The First Computer Virus
||Jamming Software, Worm
|Operating system(s) affected
Creeper was an experimental self-replicating program written by Bob Thomas at BBN in 1971. It was designed not to damage but to demonstrate a mobile application. It is generally accepted to be the first computer virus.  Creeper infected DEC PDP-10 computers running the TENEX operating system.
The Reaper program was a computer worm, like Creeper, but its purpose was to delete the latter. This fact was an inspiration for Core War, and for the D-Reaper, a major enemy in Digimon Tamers.