diff --git a/merge_sort.js b/merge_sort.js
new file mode 100644
index 0000000..32d2554
--- /dev/null
+++ b/merge_sort.js
@@ -0,0 +1,35 @@
+// Generated by CoffeeScript 1.10.0
+(function() {
+  var merge, merge_sort;
+
+  merge = function(left, right, comparison) {
+    var result;
+    result = new Array();
+    while ((left.length > 0) && (right.length > 0)) {
+      if (comparison(left[0], right[0]) <= 0) {
+        result.push(left.shift());
+      } else {
+        result.push(right.shift());
+      }
+    }
+    while (left.length > 0) {
+      result.push(left.shift());
+    }
+    while (right.length > 0) {
+      result.push(right.shift());
+    }
+    return result;
+  };
+
+  merge_sort = function(array, comparison) {
+    var middle;
+    if (array.length < 2) {
+      return array;
+    }
+    middle = Math.ceil(array.length / 2);
+    return merge(merge_sort(array.slice(0, middle), comparison), merge_sort(array.slice(middle), comparison), comparison);
+  };
+
+  exports.merge_sort = merge_sort;
+
+}).call(this);