diff --git a/source/Ox/js/Async.js b/source/Ox/js/Async.js
index 94ddb258..36ee4ec2 100644
--- a/source/Ox/js/Async.js
+++ b/source/Ox/js/Async.js
@@ -1,3 +1,5 @@
+'use strict';
+
 (function() {
 
     function asyncMap(forEach, col, iterator, that, callback) {
@@ -32,7 +34,7 @@
         (col, iterator[, that], callback[, ms]) -> <u> undefined
     @*/
     Ox.nonblockingForEach = function(col, iterator, that, callback, ms) {
-        var i, keys, last = Ox.last(arguments), n, time, type = Ox.typeOf(col);
+        var i = 0, keys, last = Ox.last(arguments), n, time, type = Ox.typeOf(col);
         callback = Ox.isFunction(last) ? last : arguments[arguments.length - 2];
         col = type == 'array' || type == 'object' ? col : Ox.toArray(col);
         keys = type == 'object' ? Object.keys(col) : Ox.range(col.length);
@@ -44,16 +46,25 @@
         time = +new Date();
         iterate();
         function iterate() {
-            keys[i] in col && iterator.call(that, col[keys[i]], keys[i], col);
-            if (++i < n) {
-                if (+new Date() < time + ms) {
-                    iterate();
-                } else {
-                    setTimeout(function() {
-                        time = +new Date();
-                        iterate();
-                    });
+            Ox.forEach(keys.slice(i), function(key) {
+                if (key in col) {
+                    try {
+                        iterator.call(that, col[key], key, col);
+                    } catch(e) {
+                        if (e === Ox.BreakError) {
+                            i = n;
+                        }
+                        throw e;
+                    }
                 }
+                i++;
+                +new Date() >= time + ms && Ox.break();
+            });
+            if (i < n) {
+                setTimeout(function() {
+                    time = +new Date();
+                    iterate();
+                }, 1);
             } else {
                 callback();
             }
@@ -62,28 +73,38 @@
 
     /*@
     Ox.nonblockingMap <f> Non-blocking map with synchronous iterator
-        (col, iterator[, that], callback) -> <u> undefined
+        (col, iterator[, that]) -> <u> undefined
         col <a|o|s> Collection
         iterator <f> Iterator function
         that <o> The iterator's this binding
         callback <f> Callback function
         <script>
             var time = +new Date();
-            Ox.serialMap(
-                Ox.range(10),
-                function (value, index, array, callback) {
-                    setTimeout(function() {
-                        callback(+new Date() - time);
-                    }, Ox.random(1000));
+            Ox.nonblockingMap(
+                Ox.range(1000000),
+                function (value, index, array) {
+                    return +new Date() - time;
                 },
                 function(results) {
-                    Ox.print(results);
-                }
+                    Ox.print(results.length);
+                },
+                1000
             );
         </script>
     @*/
-    Ox.nonblockingMap = function() {
-        asyncMap.apply(null, [Ox.nonblockingForEach].concat(Ox.toArray(arguments)));
+    Ox.nonblockingMap = function(col, iterator, that, callback, ms) {
+        var last = Ox.last(arguments),
+            type = Ox.typeOf(col),
+            results = type == 'object' ? {} : [];
+        callback = Ox.isFunction(last) ? last : arguments[arguments.length - 2];
+        that = arguments.length == 5 || (
+            arguments.length == 4 && Ox.isFunction(last)
+        ) ? that : null;
+        Ox.nonblockingForEach(col, function(val, key, obj) {
+            results[key] = iterator.call(that, val, key, obj);
+        }, function() {
+            callback(type == 'string' ? results.join('') : results);
+        }, ms);
     };
 
     /*@