Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.

官网：https://modernizr.com/

Modernizr

又拍云CDN（官网：http://jscdn.upai.com/）

//upcdn.b0.upaiyun.com/libs/modernizr/modernizr-2.7.1.min.js
//upcdn.b0.upaiyun.com/libs/modernizr/modernizr-2.6.2.min.js
//upcdn.b0.upaiyun.com/libs/modernizr/modernizr-2.6.1.min.js
//upcdn.b0.upaiyun.com/libs/modernizr/modernizr-2.5.3.min.js