Of the top 20, I've got one fifth of them using jQuery: Amazon, eBay, Wikipedia, and MSN. Not in the hospital yet.
Google uses jQuery (and hosts it for millions of sites), just not on their very optimized homepage. They built a very large framework of their own to power their apps, but a lot of their informational sites use jQuery. Here are some examples:
https://developers.google.com http://www.chromeexperiments.com http://developer.android.com
The only one you listed that doesn't seem to is Wikipedia. You really should actually try the websites before you list them.
Also, your idea below about sniffing for $ is a bit embarrassing. Firefox, Chrome, etc. have come with $ for many years as an ID or query selector, and it has nothing to do with jQuery. Prototype and MooTools also provide $, and probably a dozen or more similar libraries you haven't heard of.
I clearly said you can not just check for `$`.
edit: ok now I get it, I had a look at your website. You like Closure so jQuery must suck, right? Also I would be in the hospital after 5 shots....
My personal advocacy for the Closure Tools does not discredit my views on other tools, and I'm hoping this ad hominem nonsense doesn't fly in such a forum. Quite a few people come into the IRC channel and are using the Closure Compiler with jQuery and I don't give them shit. I take no issue with you using, liking, preferring jQuery.
You know why I like Closure? Because it makes the hard things possible. When you're talking about JavaScript running the web, it's websites like Gmail that matter the most. And you'd have a hell of a time getting Gmail to run as smoothy as it does using a library like jQuery, or even ExtJS.
Virtually everybody is far more than a majority.
