The original code for vi was written by Bill Joy in 1976, as the visual mode for a line editor called ex that Joy had written with Chuck Haley.
Prenosljivo podmnožico obnašanja vi in programov, ki temeljijo na njem, ter urejevalniškega jezika ex, ki ga podpirajo, definirata in tako tudi standardizirata družini standardov Single UNIX Specification (SUS) in POSIX.