The following lines were added (+) and removed (-):
=== ed ===An editor for UNIX written in PDP-11/20 assembler in 1971 by Ken Thompson. Now there is GUN-ed for Linux. ed is a line-oriented text editor. It is used to create, display, modify and otherwise manipulate text files. red is a restricted ed: it can only edit files in the current directory and cannot execute shell commands. === nvi ===