Test if browser supports fractional values of letter spacing

support.letterspacing.js

/* Test if the browser supports decimal letterspacing for fine kerning (f.ex 0.5px)
 * At the moment (january 2012), at least webkit (chrome & safari) does not render decimal pixels correctly
 * https://bugs.webkit.org/show_bug.cgi?id=20606
 * Using this method, you can at least provide an alternative kerning for those browsers
 */

var letterspacing = (function(d) {
    var test = d.createElement('div'),
        ret = true;
    test.style.letterSpacing = '.5px';
    d.body.appendChild(test);
    if (d.defaultView && d.defaultView.getComputedStyle) {
        if (d.defaultView.getComputedStyle( test, null ).letterSpacing == 'normal') {
            ret = false;
        }
    }
    d.body.removeChild(test);
    test = null;
    return ret;
}(window.document));