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 (LA

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.