dhtmlxTree is a JavaScript Tree component that represents hierachically organized data the best way.
Light-weight , high-performance, having clear and comfortable API, well documented this DHTML tree is highly useful for representation of data in commercial applications or on your web site. Dynamical loading of items by opening of subnodes, gives possibility to satisfy client's requirements to display really huge amounts of data fetched from database.
The tree state can be saved/restored in a cookie so when user visits the page next time, he finds the tree in the same state he left it.
dhtmlxTree is compatible with all main Web-browsers for Windows, Mac OS X, Linux or Unix. You can customize "look and feel" of the tree to suit best your needs - use font style & color and icons design to create your unique style. You can use tree without icons and include multi-line tree items. Suitable component API allows to control it at runtime.
dhtmlxTree has XML support, search functionality, drag-&-drop (within one tree, between trees, between frames), built-in checkboxes (two/three states) and context menu.

Free for non-commercial use.

Features:
- Multibrowser/Multiplatform support
- Full controll with JavaScript API
- Dynamic loading
- XML support
- drag-n-drop (within one tree, between trees, between frames)
- checkboxes (two/three states)
- customizable icons (with javascript or xml)
- context menu
- user data for nodes
- saving/restoring tree state in cookie
- search functionality
- Macromedia Cold Fusion support