Okay, prototype.js is no doubt useful and even essential for the admin area of WordPress, but you may find, as I did, that you're inadvertently slowing down your site by a huge amount by using certain plugins that call this massive script.
The problem: prototype.js is a whopping 124kb. I found that each page on my site, once you added up all the html, css, images, and scripts, was coming in at half a megabyte. That's ludicrous. And half of the size was due to prototype.js. Even optimizing this script by stripping out all the whitespace leaves it at 92kb.
After doing a little research I found that there were certain plugins that were calling this script:
- Share this
- Collapsible Archive Widget
Now I like Alex King's Share This plugin, for example, but I had to decide whether the annoyance of visitors having to download half a megabyte was balanced by the benefits few people that actually use that plugin. I decided it wasn't.
Two of the other plugins were disabled (I've just listed them to be informative). The fourth was one I'd just installed but hadn't started using.
I also found that a plugin was adding a call to jquery.js to every page, when I only needed it on the home page. So I wrapped that in a conditional tag so it only appears when needed.
Anyway, I'd suggest looking in the code view of your browser and seeing if prototype.js is being called. If it is, you might want to decide whether fast-loading pages are more beneficial to your site's visitors than the benefits of the plugins you're using.
My pages are now about 40kb (much better than 500kb!) and load very quickly.
Anyone else found plugins that call prototype.js?