diff --git a/README.md b/README.md
index 4e8d6c170..3ef5c4d61 100755
--- a/README.md
+++ b/README.md
@@ -66,6 +66,7 @@ List of Definitions
 * [d3.js](http://d3js.org/) (from TypeScript samples)
 * [dhtmlxGantt](http://dhtmlx.com/docs/products/dhtmlxGantt) (by [Maksim Kozhukh](http://github.com/mkozhukh))
 * [dhtmlxScheduler](http://dhtmlx.com/docs/products/dhtmlxScheduler) (by [Maksim Kozhukh](http://github.com/mkozhukh))
+* [diff](https://github.com/kpdecker/jsdiff) (by [vvakame](http://github.com/vvakame))
 * [Dock Spawn](http://dockspawn.com) (by [Drew Noakes](https://drewnoakes.com))
 * [docCookies](https://developer.mozilla.org/en-US/docs/Web/API/document.cookie) (by [Jon Egerton](https://github.com/jonegerton))
 * [domo](http://domo-js.com/) (by [Steve Fenton](https://github.com/Steve-Fenton))
diff --git a/diff/diff-tests.ts b/diff/diff-tests.ts
new file mode 100644
index 000000000..1588f5947
--- /dev/null
+++ b/diff/diff-tests.ts
@@ -0,0 +1,14 @@
+/// <reference path="./diff.d.ts" />
+
+import jsdiff = require('diff');
+
+var one = 'beep boop';
+var other = 'beep boob blah';
+
+var diff = jsdiff.diffChars(one, other);
+
+diff.forEach(function (part) {
+    var mark = part.added ? '+' :
+        part.removed ? '-' : ' ';
+    console.log(mark + " " + part.value);
+});
diff --git a/diff/diff.d.ts b/diff/diff.d.ts
new file mode 100644
index 000000000..9ccbb10a8
--- /dev/null
+++ b/diff/diff.d.ts
@@ -0,0 +1,57 @@
+// Type definitions for diff
+// Project: https://github.com/kpdecker/jsdiff
+// Definitions by: vvakame <https://github.com/vvakame/>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare module JsDiff {
+    interface IDiffResult {
+        value: string;
+        added?: boolean;
+        removed?: boolean;
+    }
+
+    interface IBestPath {
+        newPos: number;
+        componenets: IDiffResult[];
+    }
+
+    class Diff {
+        ignoreWhitespace:boolean;
+
+        constructor(ignoreWhitespace?:boolean);
+
+        diff(oldString:string, newString:string):IDiffResult[];
+
+        pushComponent(components:IDiffResult[], value:string, added:boolean, removed:boolean):void;
+
+        extractCommon(basePath:IBestPath, newString:string, oldString:string, diagonalPath:number):number;
+
+        equals(left:string, right:string):boolean;
+
+        join(left:string, right:string):string;
+
+        tokenize(value:string):any; // return types are string or string[]
+    }
+
+    function diffChars(oldStr:string, newStr:string):IDiffResult[];
+
+    function diffWords(oldStr:string, newStr:string):IDiffResult[];
+
+    function diffWordsWithSpace(oldStr:string, newStr:string):IDiffResult[];
+
+    function diffLines(oldStr:string, newStr:string):IDiffResult[];
+
+    function diffCss(oldStr:string, newStr:string):IDiffResult[];
+
+    function createPatch(fileName:string, oldStr:string, newStr:string, oldHeader:string, newHeader:string):string;
+
+    function applyPatch(oldStr:string, uniDiff:string):string;
+
+    function convertChangesToXML(changes:IDiffResult[]):string;
+
+    function convertChangesToDMP(changes:IDiffResult[]):{0: number; 1:string;}[];
+}
+
+declare module "diff" {
+    export = JsDiff;
+}