fib.js

// Simple fibonacci series generator.  Generates fibonacci series from 0 to `limit` number.
    function fib (limit) {
        var out = [],
            a = 0,
            b = 1;
        while (a < limit) {
            out.push(a);
            if (b <= limit) {
                out.push(b);
            }
            a = a + b;
            b = a + b;
        }
        return out;
    }