SED, the Stream Editor
Eric Pement's Cornerstone Mag site hosts an extensive FAQ, download sites for most operating systems, large list of handy
           oneliners, table of version differences, exhaustive links.
                       http://www.cornerstonemag.com/sed/

                         Batch and Third-Party Programs
      Benny Pedersen gives examples of the use of SED in DOS batch files.
            http://users.cybercity.dk/~bse26236/batutil/help/SED.HTM

                              Custom SED Proposal
    Wish list and manifesto for development of a new version of the editor.
                    http://www.ptug.org/sed/custom_sed.html

                        GNU SED version 3.02.80 for OS/2
             A port of the program for OS/2, requires RPM and EMX.
                http://www2s.biglobe.ne.jp/~vtgf3mpr/gnu/sed.htm

                      Roger Chang's SED and Shell Scripts
               SED and Bourne Shell scripts by a seder in Taiwan.
                    http://main.rtfiber.com.tw/~changyj/sed/

                                      SED
              The Open Group "Single UNIX Specification" man page.
            http://www.opengroup.org/onlinepubs/7908799/xcu/sed.html

                             SED - a Stream EDitor
Felix von Leitner explains why anybody would want to use SED, gives a small tutorial.
                   http://www.math.fu-berlin.de/~leitner/sed/

                                   SED & AWK
           The most popular book on the stream editor, from O'Reilly.
               http://www.oreilly.com/catalog/sed2/noframes.html

                            SED - the stream editor
                        Sven Guckes's scripts and links.
                   http://www.math.fu-berlin.de/~guckes/sed/

                            SED FAQ (He Sed She Sed)
Dreamwvr.com's alternate frequently asked questions list is arranged in increasing order of difficulty, and can be read as a
                                   tutorial.
                 http://www.dreamwvr.com/sed-info/sed-faq.html

                                 SED Tutorials
Some items selected by Yiorgos Adamopoulos from the Seders grab bag and mailing list.
                   http://www.dblab.ece.ntua.gr/~george/sed/

                                Sokoban for SED
               The timeless Sokoban game written in a SED script.
                        http://verde666.org/sed/sokoban