XTree.NET is a .NET/Mono webcontrol which produces a menu tree like the one you see here on the left (if you can not see the tree menu click here).
The tree produced by XTree.NET works on the most common browsers. The current version has been tested on Microsoft IE 6.0.2800.1106, Netscape 7.2 and Opera 7.54.
XTree.NET is released under the GNU Public License.
PS. The tree you see here is not the actual output of the XTree.NET webcontrol. Since sourceforge servers do not support Mono yet. The tree is however a potential output from the XTree.NET webcontrol. DS.