Python で

def tail(fun, *args):
  return (fun, args)

def call_with_tco(fun, *args):
  esc = args[-1]
  c = (fun, args)
  while c[0] != esc:
    c = c[0](*c[1])
  return c[0](*c[1])

def identity(x):
  return x

def fact(n, acc, k):
  if n > 0:
    return tail(fact, n - 1, acc * n, k)
  else:
    return tail(k, acc)

print(call_with_tco(fact, 5, 1, identity))

ほぼ Scheme 版そのまま...JavaScript 版みたいにもできるかな？