Mootools, Scriptaculous, Prototype, YUI or JQuery?

[eluser]Edemilson Lima[/eluser]
I did made my own Ajax class, my own popup window with layers, my own autocomplete, etc, and sincerely, it not worth to build your own JS library, since it will not work fine with every browser. That is a lot of headache you can avoid using any of these JS libraries. Nothing is perfect, but is better waste your time with your application than with your own libraries.