Objective Caml version 3.07+2

let rec tarai x y z =
  if x <= y then y
  else tarai (tarai (x - 1) y z) (tarai (y - 1) z x) (tarai (z - 1) x y);;
Printf.printf "%d\n" (tarai 12 6 0)

=> 0.036 / ruby 1.8.1 (2003-12-25) [powerpc-darwin]

Gauche scheme interpreter, version 0.7.3
(define (tarai x y z)
  (if (<= x y)
    y
    (tarai (tarai (- x 1) y z)
      (tarai (- y 1) z x)
      (tarai (- z 1) x y))))
(tarai 12 6 0 )

=> 0.097 / ruby 1.8.1 (2003-12-25) [powerpc-darwin]

Gaucheの結果が>>82とかなり違うなぁ。
噂に違わずOcaml速えぇ。