I think many commenters are misunderstanding the main idea here. This page makes a strong case if you're just using jQuery for a few things in your site. I can see people complaining "why would I write all that code again? if jQuery offers a beautiful API?" if you're just using jQuery to do a few simple things (Which I've seen all over the place among peers) then why not just write the native version? it's only a few lines and you're saving a whole library in your load process