CodeEval solutions. Updated as additional problems are solved.

codeeval.js

/**
  * FizzBuzz
  */
function codeEvalExecute(line) {
    var spec = line.split(" ").map(function(x, i) {
    	return +x; // Cast to int
	}), i = 1, out = "", cur = "";
	for (; i <= spec[2]; i++) {
		if (i !== 1)
			cur = " ";
		if (i % spec[0] === 0)
			cur += "F";
		if (i % spec[1] === 0)
			cur += "B";
		if (cur === " " || cur === "")
			cur += i; // string + int cases the int to be casted to a string
		out += cur;
	}
	return out;
}

function palindrome_check(number) {
	if (number < 10)
		return true; // One-digit numbers are unimpressive palindromes

	var number = number.toString().split(""), i = 0, l = number.length,
		palindrome = true;

	for ( ; l > 1; ) {
		if (number[0] !== number[l - 1]) {
			palindrome = false;
			break;
		}
		number = number.slice(1, -1);
		l -= 2;
	}
	return palindrome;
}
/**
  * Prime Palindrome
  */
function codeEvalExecute(line) {
	function getPrimes(max) {
		var sieve = [], i, j, primes = [];
		for (i = 2; i <= max; ++i) {
			if (!sieve[i]) {
				// i has not been marked -- it is prime
				primes.push(i);
				for (j = i << 1; j <= max; j += i) {
					sieve[j] = true;
				}
			}
		}
		return primes;
	}

	function palindrome_check(number) {
		if (number < 10)
			return true; // One-digit numbers are unimpressive palindromes
        
		var number_ar = number.toString().split(""), i = 0, l = number_ar.length,
			palindrome = true;

		for ( ; l > 1; ) {
			if (number_ar[0] !== number_ar[l - 1]) {
				palindrome = false;
				break;
			}
			number_ar = number_ar.slice(1, -1);
			l -= 2;
		}
		return palindrome;
	}
	
	var primes = getPrimes(1000), l = primes.length, i = l - 1;
	for ( ; i > 0; i--) {
		if (palindrome_check(primes[i]))
			return primes[i];
	}
}
/**
  * Sum first 1000 primes
  * 3682913
  */
function codeEvalExecute(line) {
	function primality_test(n) {
		if (isNaN(n) || !isFinite(n) || n % 1 || n < 2)
			return false; 
		if (n % 2 === 0)
			return (n == 2);
		if (n % 3 === 0)
			return (n == 3);
		var m=Math.sqrt(n);
		for (var i = 5; i <= m; i += 6) {
			if (n % i === 0)
				return false;
			if ( n % (i+2) === 0)
				return false;
		}
		return true;
	}
	
	for (var i = 0, j = 0, sum = 0; i < 1000; j++) {
		if (primality_test(j)) {
			sum += j;
			i++;
		}
	}
	return sum;
}
/**
  * Lowercase
  */
function codeEvalExecute(line) {
	return line.toLowerCase();
}
/**
  * Word Reverse
  */
function codeEvalExecute(line) {
	return line.split(" ").reverse().join(" ");
}