a JavaScript library allowing you to use CSS3 & HTML5 while maintaining control over unsupported browsers
Modernizr is a script that will detect native CSS3 and HTML5 features available in the current UA and provide an object containing all features with a true/false value, depending on whether the UA has native support for it or not.
In addition to that, Modernizr will add classes to the <html>
element of the page, one for each cutting-edge feature. If the UA
supports it, a class like cssgradients will be added. If not,
the class name will be no-cssgradients. This allows for simple
if-conditionals in CSS styling, making it easily to have fine
control over the look and feel of your website.
Modernizr is dual-licensed under the BSD and MIT licenses.
Run the library: http://modernizr.github.com/Modernizr/output.html
Run the test suite: http://modernizr.github.com/Modernizr/test/