stack based languages

Hello, i am interested in learning a stack oriented language, so i started learning Forth. (from http://www.amresearch.com/starting_forth/)
Some alternatives i heard of are cat and factor.

What is best to learn from those? And suggest a good tutorial

>>8
That's almost as ugly as Perl. You want to calculate Fibonacci numbers, and you have to put up with the stack. The language model clearly gets in your way. You need to know Factor to understand these lines, yet I can't possibly think of a Fibonacci implementation that's not trivial in any other language:


(define (fib x)
        (if (< x 2)
            x
            (+ (fib (- x 1)) (fib (- x 2)))))

def fib(x):
    if x < 2: return x
    else:     return fib(x - 1) + fib(x - 2)

fib(x) = lambda x if x < 2 else fib(x - 1) + fib(x - 2)

unsinged int fib(unsigned int x) {
    return x < 2 ? x : fib(x - 1) + fib(x - 2)
}