Speed up your AJAX based webapps
UPDATE : I guess most people are not getting what this technique does in the first place. It sets the expiry of the JavaScript to years and not days. Once the JavaScript file is downloaded it is never downloaded again, ofcourse unless you force it by removing the file in the cache. If you visit the site often the JavaScript will not be removed from the cache. If you make any changes to the JavaScript you only need to change the version of the file and the new file will be downloaded. The older file is automatically removed from the cache when it is no longer requested. And just to add one more point this can be done on the WebServer itself without using this technique, but that has its own drawbacks. To further speed up the download you can gzip the JavaScript. If you have developed an AJAX based web application you would know how many JavaScript files are required per webpage. If you use the prototype or dojo toolkit library you would know how big those JavaScript files can t