KoolTreeView is the excellent treeview control for PHP, combining highly-efficient rendering and AJAX Load on Demand support for superior performance. Features: (1) Render Thousand nodes in a second (2) Very simple PHP interface (3) Rich Client-side API (4) Search-Engine Friendly (5) Drag and Drop behavior (6) Edit Node behavior (7) Multiple-nodes Selection feature (8) AJAX-based Loading on Demand (9) State-persistent capability (10) Style can be all customized.