Modernizr is an open-source JavaScript library that helps you build the next generation of HTML5 and CSS3-powered websites.
Modernizr is a small JavaScript library that detects the availability of native implementations for next-generation web technologies, most commonly 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). Modernizr tells you whether the current browser has this feature natively implemented or not.
The most recent version of Modernizr is Modernizr 2.5, released 6 Feb 2012. More information is available at the Modernizr home page.
When Modernizr v2 was released in June 2011, it made a significant departure from v1 (and from most other common JavaScript libraries): Where version 1 included all the feature detection tests in a single standard script, version 2 allows a site developer to build their own personalized copy of Modernizr that contains only the tests required. This allows a developer to minimize the amount of JavaScript code that their users need to download. However, it also reduces the scope to use a shared content delivery network (CDN) such as Google Code.
