sed

• was written 1973 or 1974 by Lee E. McMahon
• is an acronym for stream editor
• uses Basic Regular Expressions
• works as follow
  1. read a entire line from stdin in its pattern buffer
  2. modify the pattern buffer according to the supplied commands
  3. print the pattern buffer to stdout
  4. if not EOF then goto 1
• has roughly 20 commands which makes of him a real RISE (Reduced Instruction Set Editor)