I also added extra comments (my own notes as I figured things out) in a copy up on my old website (with permission) -- I didn't know about the above appendix at the time. I'm not sure if it'd add anything to the above, but I could dig it up.
Gambit also hits another naming convention for Scheme implementations: that they be synonyms for "scheme" or related to it.
Scheme, Gambit, Racket, Guile, Larceny.
Gauche might be an antonym?
(IIRC, Racket got its name shortly before they were looking into promoting its use on Wall Street. I guess OCaml didn't have the problem of lighting up the regulatory compliance monitoring board every time someone mentioned "Racket" in email.)
Rabbit was the first. I read somewhere that this was a kind of pun on the MacLisp LAPIN function. LAPIN assembled LAP code, Lisp Assembly Program (the penultimate stage of compilation), and 'lapin' is French for rabbit.
I understood it was wordplay from lapin, the French word for rabbit. The way I remember it is it was a program that took an input of Lisp Assembly Programs (LAP-in). I can't find a source for this, so I may be misremembering parts of it, particularly the expansion of the acronym.
I confess to hoping this was a compiler for rabbit schemes, but no such luck. Those things are everywhere around me (near Chicago, IL) and it would have been insightful to do some reverse-engineering. Alas, their schemes shall remain mysterious.
I also added extra comments (my own notes as I figured things out) in a copy up on my old website (with permission) -- I didn't know about the above appendix at the time. I'm not sure if it'd add anything to the above, but I could dig it up.
Related work at https://en.wikisource.org/wiki/Lambda_Papers