CoffeeScript

I've just found out about CoffeeScript which is a really neat way to make JavaScript look nicer. It can be compiled on the fly to real JavaScript. Here's one example I just wrote:

fibonacci: (x)->
 return 0 if x == 0
 return 1 if x == 1
 return fibonacci(x-1) + fibonacci(x-2)

alert fibonacci 10

which compiles into this:

var fibonacci;
fibonacci = function fibonacci(x) {
 if (x === 0) {
   return 0;
 }
 if (x === 1) {
   return 1;
 }
 return fibonacci(x - 1) + fibonacci(x - 2);
};
alert(fibonacci(10));

pretty sweet huh?