Well, I don't feel like YUI tries to make JS into Java. The goal of YUI is to add some extra APIs under a single global object, and pretty much let you write y

Well, I don't feel like YUI tries to make JS into Java. The goal of YUI is to add some extra APIs under a single global object, and pretty much let you write your code however you want. It's a library that quietly does nothing if you don't use it, and it doesn't ask you to change how you do things. jQuery is, of course, Javascript. John Resig didn't invent functional closures or chaining. But it seems like jQuery is designed to change the way that you write Javascript. It even says so on http://jquery.com/ http://jquery.com/ It's a set of conventions, and they're not standard. I'm not saying that they're bad (in fact, I really like the jQuery style and think it's very elegant.) But there's a learning curve there, and not every javascripter is a programming language geek who would get off on learning a new style.