Tooltip helps you to build easier user interfaces. Big or small. Pluggable effects. Yet another crucial tool.
Scrollable is the most successful tool in this library. Any size and shape. Infinite loops and more.
FORM is a collection of essential form building tools. Validation, range- and date inputs for humans. New wave form development is here.
jQuery Tools is a collection of the most important user-interface components for modern websites. Used by large sites all over the world.