For those of us who like the braces:

Lisp comes from List Processor.

Scheme was first called Schemer, which itself evolved out of the Planner language developed by Carl Hewitt at MIT. Schemer was shortened to Scheme to fit the ITS filesystem's six character filename limit (!) on the PDP-10.

Racket is a kind of Scheme. (I like this one)

Guile comes from Guy L. Steele, one of the initial Scheme developers. The other being Gerald Jay Sussman.