Webzu: craig:/computer/prog/regexp/sed

craig> computer> prog> regexp>
sed: Stream Editor

sed . . . the stream editor: Sed is extremely powerful, and you can do things in sed that you can't do in any standard word processor. And because sed is external to the word processor and comes with every Unix system in the world, once you learn sed you'll have a very handy tool in your toolkit, even if (like me) you rarely use Unix.
URL: http://www.student.northpark.edu/pemente/sed/index.htm

sed tutorial: This tutorial is meant as a brief introductory guide to sed that will help give the beginner a solid foundation regarding how sed works. It's worth noting that the tutorial also omits several commands, and will not bring you to sed enlightenment in itself.
URL: http://pegasus.rutgers.edu/~elflord/unix/sed.html