Best AJAX/Javascript library for RAils

Which Ajax/Javascript-based library for generating dynamic HTML works
best w/ Rails?

I'm looking at jQuery, but are there other libraries that people prefer?
That integrate well w/ Rails?


I prefer Dojo because it's an excellent base for building your own
code and the functionalities are much easier to extend, for example
when you need very customized UI widgets. In my opinion, JQuery is
good for small websites.

Comparison of JavaScript frameworks:


Does anyone know what Twitter uses? They have some interesting widgets..