The repl and window examples were just what I needed as a complete Emacs newbie. The Emacs chapter was similarly good. It seemed to be aimed at someone who wanted to start writing code quickly. This is the first time in years that I've worked through an Emacs tutorial without firing up vim to edit a config file (at which point I usually realize that I won't be switching to Emacs that day).
Thank you for taking the time to write all of this.
The api actually feels pretty similar to Python (eg rest-param ~= args) so it mapped over nicely for me. I studied functional programming some years ago and have tinkered with the like of erlang in the past so none of the concepts you presented felt too foreign.
I might be going insane but it looks like you have a typo in there - 'whether the ;; the part's name'*.
Kudos, again.
[0] http://swannodette.github.io/2013/12/17/the-future-of-javasc...