Access to these libraries is quite simple, in fact loading prototype can be accomplished with the following four lines of code:
<script src="http://www.google.com/jsapi"></script> <script> google.load("prototype", "188.8.131.52"); </script>
Pretty simple, but let’s look at some metrics.
|With Google||Without Google|
|(no cache)||(local cache)||(no cache)||(local cache)|
As you can see, the Google version is significantly faster and smaller on the initial load, subsequent loads a little less obvious, but still slightly faster. However, this test was not all that scientific, since I really only have the ability to do this with Firefox and Firebug, I only did it once, and my network speed can vary significantly from request to request. Despite all of that, testing this across a few other browser/OS combinations does reveal a pattern where the Google AJAX Library API pages do feel faster, even if only by a fraction of a second. I’ve provided my test pages, with Google and without-Google, for you to perform your own tests, and I’d love to hear what other people think and see their results.
Now, one last thought. Keep in mind that this is not the most optimal solution since it still makes a request for each library you load and the libraries themselves are not optimized, but it does bring along with it an interesting benefit. The more sites that use this service the higher the chance of getting a local cache hit on one of these files, which of course means one less download.