When using this CDN for versioned libraries like jQuery, be sure to avoid using the "latest version" references[1][2]. In order for the "latest version" featur

When using this CDN for versioned libraries like jQuery, be sure to avoid using the "latest version" references[1][2]. In order for the "latest version" feature to be reliable, they have to avoid users having stale local copies for very long. Thus, they serve those with a much closer expires header, which defeats one of the shared CDN's biggest benefits. When you reference the full version explicitly[3], it's served with a +1 year expires header. // Not cached for long. [1] http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js [2] http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.j... // Cached for up to a year. [3] http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min...