Fibonacci microbenchmark, moved to here: https://github.com/wting/fib-benchmark#performance

fib.c

// gcc -O2 fib.c
#include <stdio.h>

int fib(n) {
    if (n < 2)
        return 1;
    return fib(n-2) + fib(n-1);
}

int main(int argc, char const* argv[]) {
    printf("%d\n", fib(40));
    return 0;
}

fib.clj

(defn fib [n]
    (if (= n 0) 0
        (if (= n 1) 1
            (+ (fib (- n 1)) (fib (- n 2))))))

(defn -main
    (println (fib 30)))

fib.go

package main

import "fmt"

func fib(n int) int {
	if n < 2 {
		return 1
	}

	return fib(n-2) + fib(n-1)
}

func main() {
	fmt.Println(fib(40))
}

fib.hs

-- ghc -O -O2 -optc-O3 fib.hs
fib :: Int -> Int
fib 0 = 1
fib 1 = 1
fib n = fib(n-1) + fib(n-2)

main = do
    print (fib 40)

Fib.java

class Fib {
	static int fib(int n) {
		if (n < 2)
			return 1;
		return fib(n-2) + fib(n-1);
	}

	public static void main(String[] args) {
		System.out.println(fib(40));
	}
}

fib.lua

function fib(n) return n < 2 and 1 or fib(n-2) + fib(n-1) end

print(fib(40))

fib.py

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

print(fib(40))

fib.rb

def fib(n)
    if n < 2
        return 1
    end
    return fib(n-2) + fib(n-1)
end

puts fib(40)

fib.rc

fn fib(n: int) -> int {
    if n < 2 {
        return 1;
    }
    fib(n-2) + fib(n-1)
}

fn main() {
    io::println(fmt!("%d", fib(40)));
}

results.md

Performance

C:              0.38s
Java:           0.55s
Go:             0.90s
Rust:           1.29s
Haskell:        1.32s
LuaJit:         2.17s
PyPy:          10.06s
Lua:           21.18s
Ruby 1.9.3:    22.13s
Ruby 2.0.0:    22.13s
Python 2.7.3:  43.88s
Python 3.3.0:  66.28s

Test Machine

CPU: i7-2640M @ 2.80GHz
RAM: 16GB
HDD: SSD

The Lua version should be
function fib(n) return n < 2 and 1 or fib(n-2) + fib(n-1) end

so that fib(0) will be 1, just like your other implementations.

Edit: swapped the order of the recursive calls to be consistent with original implementation

Thanks, I've updated the code and ran the benchmark again but it only made a marginal difference (~0.1s).

The Clojure results seem to be missing.

@johntyree: Clojure results added here. Gists don't support directories so I had to migrate to a repo.