Html5 content not styled in JavascriptMVC+Modernizr. Modernizr, html5shiv, ie7.js, and CSS3 Pie. Which to use and when. CSS3 PIE: CSS3 decorations for IE. Documentation. What is Modernizr? Modernizr is a small JavaScript library that detects the availability of native implementations for next-generation web technologies, i.e. features that stem from the HTML5 and CSS3 specifications. Many of these features are already implemented in at least one major browser (most of them in two or more), and what Modernizr does is, very simply, tell you whether the current browser has this feature natively implemented or not.
Unlike with the traditional—but highly unreliable—method of doing “UA sniffing,” which is detecting a browser by its (user-configurable) navigator.userAgent property, Modernizr does actual feature detection to reliably discern what the various browsers can and cannot do. Html5 - HTML5shiv vs Dean Edwards IE7-js vs Modernizr - which to choose.