Yesterday, i took some time to evaluate Ajax libraries. I really liked MochiKit a lot but decided to use jQuery because of its wide adoption and projects like markItUp!.
Some month ago, i wrote about tracup, my rewrite of the trac markup formatter. Today i configured a markup editor for tracup with the wonderful markItUp! project. I added a django field and widget to ease the configuration for the new tracitup editor. You can add a comment and see the editor as well as some jQuery effects in action.
I was never a fan of JavaScript because of it quirks, but with handy Ajax libraries and the FireBug Debugger, it much easier to keep control.