After reading lots of similar anecdotes about Ed (Steven Levy's "Hackers" dedicates quite a few words to it), I was quite sure it was pretty much unusable for today's UI patterns, but also morbidly curious about how it might eventually work.
Then I came across "Actually using ed"[1], which did such a great job at explaining how to use the tool that I decided to throw in my 2 cents by submitting an entry to the tldr-pages project[2]. The rendered page looks can be found on [3]. Any feedback welcome!