diff --git a/source/Ox/js/Async.js b/source/Ox/js/Async.js
new file mode 100644
index 00000000..84f43c5a
--- /dev/null
+++ b/source/Ox/js/Async.js
@@ -0,0 +1,182 @@
+(function() {
+
+    function asyncMap(forEach, col, iterator, that, callback) {
+        var type = Ox.typeOf(col),
+            results = type == 'object' ? {} : [];
+        callback = Ox.last(arguments);
+        that = arguments.length == 5 ? that : null;
+        forEach(col, function(val, key, obj, callback) {
+            iterator(val, key, obj, function(v) {
+                results[key] = v;
+                callback();
+            });
+        }, that, function() {
+            callback(type == 'string' ? results.join('') : results);
+        });
+    };
+
+    Ox.asyncMap = function(arr, iterator, that, callback) {
+        callback = Ox.last(arguments);
+        that = arguments.length == 4 ? that : null;
+        if (arr.some(Ox.isArray)) {
+            Ox.serialMap(arr, function(val, key, obj, callback) {
+                Ox.parallelMap(Ox.makeArray(val), iterator, callback);
+            }, callback);
+        } else {
+            Ox.parallelMap(Ox.makeArray(val), iterator, callback);
+        }
+    };
+
+    /*@
+    Ox.nonblockingForEach <f> Non-blocking forEach
+        (col, iterator[, that], callback[, ms]) -> <u> undefined
+    @*/
+    Ox.nonblockingForEach = function(col, iterator, that, callback, ms) {
+        var i, keys, last = Ox.last(arguments), n, time = +new Date();
+        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);
+        ms = ms || 1000;
+        n = Ox.len(col);
+        that = arguments.length == 5 || (
+            arguments.length == 4 && Ox.isFunction(last)
+        ) ? that : null;
+        iterate();
+        function iterate() {
+            keys[i] in col && iterator.call(that, col[keys[i]], keys[i], col, function() {            
+                if (++i < n) {
+                    if (+new Date() < time + ms) {
+                        iterate();
+                    } else {
+                        setTimeout(function() {
+                            time += new Date();
+                            iterate();
+                        });
+                    }
+                } else {
+                    callback();
+                }
+            });
+        }
+    };
+
+    Ox.nonblockingMap = function() {
+        asyncMap.apply(null, [Ox.nonblockingForEach].concat(Ox.toArray(arguments)));
+    };
+
+    /*@
+    Ox.parallelForEach <f> forEach with asynchronous iterator, running in parallel
+        (col, iterator[, that], callback) -> <u> undefined
+        col <a|o|s> Collection
+        iterator <f> Iterator function
+            val <*> Value
+            key <n|s> Key
+            obj <a|o> The collection
+            callback <f> Callback function
+        that <o> The iterator's this binding
+        callback <f> Callback function
+    @*/
+    Ox.parallelForEach = function(col, iterator, that, callback) {
+        var i = 0, n, type = Ox.typeOf(col);
+        callback = Ox.last(arguments);
+        col = type == 'array' || type == 'object' ? col : Ox.toArray(col);
+        n = Ox.len(col);
+        that = arguments.length == 4 ? that : null;
+        Ox.forEach(col, function(val, key, obj) {
+            iterator.call(that, val, key, obj, function() {
+                ++i == n && callback();
+            });
+        });
+    };
+
+    /*@
+    Ox.parallelMap <f> Parallel map with asynchronous iterator
+        (col, iterator[, that], callback) -> <u> undefined
+        col <a|o|s> Collection
+        iterator <f> Iterator function
+            val <*> Value
+            key <n|s> Key
+            obj <a|o|s> The collection
+            callback <f> Callback function
+        that <o> The iterator's this binding
+        callback <f> Callback function
+            results <a|o|s> Results
+        <script>
+            var time = +new Date();
+            Ox.parallelMap(
+                Ox.range(10),
+                function (value, index, array, callback) {
+                    setTimeout(function() {
+                        callback(+new Date() - time);
+                    }, Ox.random(1000));
+                },
+                function(results) {
+                    Ox.print(results);
+                }
+            );
+        </script>
+    @*/
+    Ox.parallelMap = function() {
+        asyncMap.apply(null, [Ox.parallelForEach].concat(Ox.toArray(arguments)));
+    };
+
+    /*@
+    Ox.serialForEach <f> forEach with asynchronous iterator, run serially
+        (col, iterator[, that], callback) -> <u> undefined
+        col <a|o|s> Collection
+        iterator <f> Iterator function
+            val <*> Value
+            key <n|s> Key
+            obj <a|o> The collection
+            callback <f> Callback function
+        that <o> The iterator's this binding
+        callback <f> Callback function
+    @*/
+    Ox.serialForEach = function(col, iterator, that, callback) {
+        var i = 0, keys, n, type = Ox.typeOf(col);
+        callback = Ox.last(arguments);
+        col = type == 'array' || type == 'object' ? col : Ox.toArray(col);
+        keys = type == 'object' ? Object.keys(col) : Ox.range(col.length);
+        n = Ox.len(col);
+        that = arguments.length == 4 ? that : null;
+        iterate();
+        function iterate() {
+            keys[i] in col && iterator.call(that, col[keys[i]], keys[i], col, function() {
+                ++i < n ? iterate() : callback();
+            });
+        }
+    };
+
+    /*@
+    Ox.serialMap <f> Serial map with asynchronous iterator
+        (col, iterator[, that], callback) -> <u> undefined
+        col <a|o|s> Collection
+        iterator <f> Iterator function
+            val <*> Value
+            key <n|s> Key
+            obj <a|o> The collection
+            callback <f> Callback function
+        that <o> The iterator's this binding
+        callback <f> Callback function
+            err <o|u> Error object
+            results <a|o> Results
+        <script>
+            var time = +new Date();
+            Ox.serialMap(
+                Ox.range(10),
+                function (value, index, array, callback) {
+                    setTimeout(function() {
+                        callback(+new Date() - time);
+                    }, Ox.random(1000));
+                },
+                function(results) {
+                    Ox.print(results);
+                }
+            );
+        </script>
+    @*/
+    Ox.serialMap = function(col, iterator, that, callback) {
+        asyncMap.apply(null, [Ox.serialForEach].concat(Ox.toArray(arguments)));
+    };
+
+}());