The empty list is self-evaluating in Gauche, MIT, Kawa, SISC, Chibi, SCM, NexJ, STklos, SigScheme, TinyScheme, Scheme 9, Dream, Scheme 7, BDC, Xlisp, Rep, Jscheme, Schemik, VX, Oaklisp, Owl Lisp.
Racket, Gambit, Chicken, Bigloo, Guile, Scheme48/scsh, Chez, Ikarus/Vicare, Larceny, Ypsilon, Mosh, IronScheme, KSi, Shoe, Elk, RScheme, UMB signal a syntax error.