vi

A screen editor put together by Bill Joy for an early BSD release, it became the de facto standard Unix editor and a nearly undisputed hacker favorite outside of MIT, until the rise of EMACS after about 1984. It tends to frustrate new users to no end, as it will neither take commands while expecting input text nor vice versa, and the default setup provides no indication of which mode the editor is in. Nevertheless, it is still widely used and many programmers prefer it; even EMACS fans often resort to it as a mail editor and for small editing jobs (mainly because it starts up faster than the bulkier versions of EMACS).