aToolTip is a simple jQuery tooltip.
* Lightweight (only 4kb uncompressed)
* Easy to use Choice of fixed, on click or follow mouse tooltip
* Highly customizable
* Compatable with Firefox 2.5+, Safari, Opera, Chrome and Internet Explorer 6, 7 & 8
PowerTip features a very flexible design that is easy to customize, gives you a number of different ways to use the tooltips, has APIs for developers, and supports adding complex data to tooltips. It is being actively developed and maintained, and provides a very fluid user experience.