vi (text editor)

vi (spelled in lowercase and pronounced as individual letters) is the standard text editor on UNIX. vi is a modal text editor, meaning that the user presses keys to enter different modes, for example to type in the document, the user would press i for insert mode. Due to the large number of Unix variants, there are many different versions of vi, including the original written by Bill Joy, as well as vim (vi Improved), nvi (New vi, part of BSD Unix), elvis, and many others. Most of these are compatible with the original, but some, such as vim, add new features.

vi

vi editing a Hello World program in C. Tildes signify lines not present in the file.
Developer(s)	Bill Joy
Initial release	1976 (1976)
Written in	C
Operating system	Unix, Unix-like
Platform	Cross-platform
Type	Text editor
License	BSD-4-Clause or CDDL

A survey from 2009 found that Linux Journal readers used vi as the most widely used text editor.