Lisp

Scheme
Guile	Extension lang for GNU
Chicken
Chez	fast
MIT Scheme
Pseudo Scheme
Racket	Written on top of Chez (C before)
Common Lisp
ANSI Common Lisp	Paul Graham

From what I have gathered the Schemes seem more academic and language oriented while CL has more libraries and is less clean.

• Beautiful Racket: Thoughts on Racket & Chez Scheme