diff --git a/lib/ace/mode/folding/javascript_folding.js b/lib/ace/mode/folding/javascript_folding.js
new file mode 100644
index 00000000..4ba3897f
--- /dev/null
+++ b/lib/ace/mode/folding/javascript_folding.js
@@ -0,0 +1,106 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Distributed under the BSD license:
+ *
+ * Copyright (c) 2010, Ajax.org B.V.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Ajax.org B.V. nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AJAX.ORG B.V. BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+define(function(require, exports, module) {
+"use strict";
+
+var oop = require("../../lib/oop");
+var Range = require("../../range").Range;
+var CFoldMode = require("./cstyle").FoldMode;
+
+var FoldMode = exports.FoldMode = function(commentRegex) {
+    if (commentRegex) {
+        this.foldingStartMarker = new RegExp(
+            this.foldingStartMarker.source.replace(/\|[^|]*?$/, "|" + commentRegex.start)
+        );
+        this.foldingStopMarker = new RegExp(
+            this.foldingStopMarker.source.replace(/\|[^|]*?$/, "|" + commentRegex.end)
+        );
+    }
+};
+oop.inherits(FoldMode, CFoldMode);
+
+(function() {
+    this.usingRe = /^\s*using \S/;
+
+    this.getFoldWidgetRangeBase = this.getFoldWidgetRange;
+    this.getFoldWidgetBase = this.getFoldWidget;
+    
+    this.getFoldWidget = function(session, foldStyle, row) {
+        var fw = this.getFoldWidgetBase(session, foldStyle, row);
+        if (!fw) {
+            var line = session.getLine(row);
+                if (/^\s*\/\/#region\b/.test(line))
+                    return "start";
+        }
+        return fw;
+    };
+    
+    this.getFoldWidgetRange = function(session, foldStyle, row) {
+        var range = this.getFoldWidgetRangeBase(session, foldStyle, row);
+        if (range)
+            return range;
+
+        var line = session.getLine(row);
+        if (/^\s*\/\/#region\b/.test(line))
+            return this.getRegionBlock(session, line, row);
+    };
+    
+    this.getRegionBlock = function(session, line, row) {
+        var startColumn = line.search(/\s*$/);
+        var maxRow = session.getLength();
+        var startRow = row;
+        
+        var re = /^\s*\/\/#(end)?region\b/;
+        var depth = 1;
+        while (++row < maxRow) {
+            line = session.getLine(row);
+            var m = re.exec(line);
+            if (!m)
+                continue;
+            if (m[1])
+                depth--;
+            else
+                depth++;
+
+            if (!depth)
+                break;
+        }
+
+        var endRow = row;
+        if (endRow > startRow) {
+            var endColumn = line.search(/\S/);
+            return new Range(startRow, startColumn, endRow, endColumn);
+        }
+    };
+
+}).call(FoldMode.prototype);
+
+});