jlc (06/25/82)
A version of ed was included in the book "Software Tools" by Kernighan and Plauger. The book was published by Addison-Wesley Publishing Company in 1976. There was also a tape available from the same company that provided the source code and documentation for enhanced versions of the programs given in the book. All source code was written in ratfor. I don't know if the tape or book is still available, but you should be able to find a copy.
rick (06/25/82)
The publisher is indeed Addison-Wesley, *not* McGraw-Hill as I stated in my previous summary of responses.