diff --git a/README.md b/README.md
index 6c8a6e3..f6d570c 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,10 @@ WelsonJS - Build a Windows desktop apps with JavaScript, HTML, and CSS based on
 ## Structure
 ![Structure of WelsonJS](app/assets/img/structure.png)
 
+## Specifications
+- ES5(ECMAScript 5), ES6(ECMAScript 6) compatibility with [es5-shim](https://github.com/es-shims/es5-shim) and [es6-shim](https://github.com/es-shims/es5-shim)
+- HTML5 compatibility with [html5shiv](https://github.com/aFarkas/html5shiv) and [jquery-html5-placeholder-shim](https://github.com/jcampbell1/jquery-html5-placeholder-shim)
+
 ## Included libraries
 - lib/std (Standard library)
 - lib/system (System library)