Simple y funcional jQuery plugin que chequea si una fuente de texto está disponible para el navegador cliente.

/* fontAvailable jQuery Plugin, v1.0
*
* Copyright (c) 2009, Howard Rauscher
* Licensed under the MIT License
*/

(function($) {
$.fontAvailable = function(fontName) {
var element, width;

// prepare element, and append to DOM
element = $(document.createElement('span'))
.css('visibility', 'hidden')
.html('abcdefghijklmnopqrstuvwxyz')
.appendTo(document.body);

// get the width of element after applying a fake font
width = element
.css('font-family', '__FAKEFONT__')
.width();

element.css('font-family', fontName);

return (width !== element.width());
}
})(jQuery);[/JavaScript]

Modo de uso:[JavaScript]$(document).ready(function() {
if($.fontAvailable('tahoma')) {
// analytic code here
}
});

jQuery fontavailable en google code.