An Acronym for Stream EDitor
A very simple ProgrammingLanguage geared towards text manipulation for files larger than the avaliable RAM. SED scripts are very hard to read if they try to do anything even moderatly complex; you're better of using AWK or Perl in such cases. The latter has copied many concepts from both of the former languages.
See sed(1).
Some SedOneLiners? for those that do like sed though...
CategoryProgrammingLanguages, CategorySpecialPurposeProgrammingLanguages
5 pages link to SED: