JavaScript tree / treegrid libraries
<p>I'm looking for a good JavaScript tree / treegrid package.  Now -- before you answer:</p>

<p>It needs to be able to perform well with <em>lots</em> of nodes.  Perhaps 1,000 sibling nodes.  It needs to be able to draw to a usable state within 2 or 3 seconds with 1,000 nodes.  It doesn't necessarily need to draw all 1,000 nodes at once -- if it supports some sort of "smart rendering" or fake scrolling.</p>

<p>Beyond that, column resizing, drag and drop, inline editing would all be nice, although I could probably add that functionality myself.  </p>

<p>I've already tried dojo's tree and yahoo's YUI treeview.  Both are too slow.</p>
