[development] AJAX Frameworks

[drupal]

> Wondering who has had good experiences with AJAX/JSON frameworks working
> with PHP/Drupal?  I realize that "frameworks" covers a multitude of sins
> - but if you've worked with something you like along these lines and it
> is Free and plays well with Drupal I'd love to hear about it.

I'm using dojo for what it's worth. The problem is that for interesting
things I have to patch core.