Scriptaculous, MooTools, jQuery and much more: all you need to develop modern web interfaces and add new features to your website.
SoundManager 2 is a Javascript Sound API which talks to Flash, effectively mapping most of Flash 8's native sound capabilities to Javascript. It enables web developers and front-end engineers to programmatically control sound in a cross-browser/platform
A small tutorial on how to build a password strength meter like the one on Google's new account form.