I am also the co-author of SED, an all-purpose disk/file/memory monitor program for Atari ST and TT computers. It was written by Anton Stepper and myself, and it was part of our book Scheibenkleister. After the book went out of print, we decided to turn it into a Mausnet project, i.e. the sources were published in the German Mausnet, and some folks there added fixes and improvements to it.
The last version (which I am aware of) is 5.68 and contains several patches by Rainer Seitel.