There is an interview where he explains what he likes about Emacs:
I have special Emacs modes to help me classify all the tens of thousands of papers and notes in my files, and special Emacs keyboard shortcuts that make bookwriting a little bit like playing an organ.
Probably one of the few rational vi/emacs arguments I've seen. And it also is a good reason why I like vi, given that I can barely hit two keys on a piano at the same time.
That emacs mode is amusing. Someone should tell him about macros :)
(I'm not trying to be critical, BTW. I just find it interesting when extraordinary people do ordinary things, like writing an emacs mode to colorize a given line.)
Well, I must admit I didn't try every link so perhaps one of them might be valid but lets see what happens when we try the first few:
cweb - The requested URL /~uno/cweb.html was not found on this server.
Axioms and Hulls - The requested URL /~uno/aah.html was not found on this server.
Computer Musings - The requested URL /~uno/musings.html was not found on this server.
See the recent one:
http://www-cs-faculty.stanford.edu/~knuth/programs.html
By the way, Donald Knuth uses Emacs to write TeX :-)