VIrus (VI resembling utility skeleton) was originally taken from
busybox and stripped of most unrelated stuff. The intention is to
provide a pure, minimalist VI implementation that allows you to switch
off shell-escaping and other security risks by default, and allow the
admin to offer an interim user to just have a vi as login-shell on a
certain host, while allowing others to work with a resource-sensitive
and small vi implementation for your OS bootdisks.