Basic feature detection with prefix support.

supports.js

var Supports = (function(){
    // all spaces are important!
    var prefixes = ' -webkit- -moz- -o- -ms- ';
    
    function getPrefixedProperties(property, prefixes) {
        var properties = prefixes.join(property + " ").split(' ');
        
        // ignore the last string which is empty.
        return properties.slice(0, properties.length-1);
    }
    
    return{
        cssProperty: function(property, host) {
            var host = host || document.body;
            var cssPrefixes = prefixes.split(' ');

            // build an array of prefixed properties.
            var properties = getPrefixedProperties(property, cssPrefixes);

            for (var i = 0, len = properties.length; i < len; i++){
                if (host.style[properties[i]] !== undefined){
                    return true
                }
            }

            return false
        },
        
        omProperty: function(property, host) {
            var host = host || document.body;
            var omPrefixes = prefixes.replace(/-/g, '').split(' ');

            // drop the first element, which is empty
            omPrefixes = omPrefixes.slice(1, omPrefixes.length);

            // uppercase the property to attach prefixes
            var ucProperty = property.charAt(0).toUpperCase() + property.slice(1)

            // build an array of prefixed properties.
            var properties = getPrefixedProperties(ucProperty, omPrefixes);

            // ignore the last string which is empty.
            properties = properties.slice(0, properties.length-1);

            // add the unprefixed property
            properties.unshift(property)

            for (var i = 0, len = properties.length; i < len; i++){
                if (properties[i] in host){
                    return true
                }
            }

            return false
        }
    }
})()

supports_usage.js

// true if CSS Regions is supported
Supports.cssProperty('flow-into');

// true if CSS Regions Object Model is supported
Supports.omProperty('getNamedFlows');