When I saw this among the passe Jeffrey Archers and Danielle Steels, my first thought was that I was not interested in Emacs, but then I realised it was interesting both historically and in containing things such as the GNU Manifesto.
The technical part of the manual is written with logical - almost painful - precision. He thinks of everything from first principles. Eg he has to explain what a key is :-
"A complete key - where "key" is short for key sequence - is a sequence of keystrokes that are understood by Emacs as a unit, as a single command (possibly undefined). Most single characters constitute complete keys .."
What he is saying is that you can type a key like the letter "a", or you can invoke a control with a combination like "Ctrl-a".
"The space character is referred to as SPC, even though strictly speaking it is a graphic character whose graphic happens to be blank"
Priceless stuff! So I've been using a computer all these years and did not really know what the space bar was!
At the end of the book there is a section on mail-ordering Emacs. It is free, but you pay for the media, like $200 for Unix systems on 1600 bpi 9-track tape in Tar format.
In the GNU Manifesto he gives a report on the progress of the GNU Operating System. "So far", he writes, "we have an Emacs editor .. a debugger .. parser generator, a linker, and around 35 utilities. A shell .. is nearly complete. A .. C compiler has compiled itself and may be released this year. An initial kernel exists but many more features need to be added .. "
How does a compiler compile itself?
Sad he never did finish that kernel, and never will, which is where the Linux kernel came in. It looks like RMS got embroiled with adding bells and whistles to Emacs when he should have got on with that kernel, and we would have been using GNU today, not Linux. He has had a chip on his shoulder about it ever since.
I rate RMS as a modern-day genius, but a flawed one.