1. I can only add 4 nodes to the root of the tree.
2. Menu not working on Netscape (applet not found).
3. Can I use RTree Visual Designer to create RMenus (horizontal and vertical)?

This is a restriction in the evaluation version (free for personal use ) of RTree.

try using the parameter CODEBASE = "./" .

the Designer can only be used to create Trees not horizontal or vertical Menus. However you can also image a Menu as a Tree. You can create a Tree and then modify the resulting HTML code to be used as a Menu For example:

1. load Example1 in the Designer.
2. Generate the HTML code (File->generate)
3. Edit the HTML page with notepad and put this:

   <APPLET CODEBASE = "."
   CODE = "com.java4less.rmenu.RMenuApplet.class"
   NAME = "TestApplet"
   ARCHIVE = "RMenud.zip" WIDTH = 800 HEIGHT = 340 >
   <PARAM NAME = "TREE_MENU_TYPE" VALUE = "HORIZONTAL">
   <PARAM NAME = "NODE_SUBMENUCOLOR" VALUE = "LIGHTGRAY">
   <PARAM NAME = "NODE_SUBMENU_BORDER" VALUE = "RAISED">
   <PARAM NAME = "TREE_ITEM_WIDTH" VALUE = "100">
   <PARAM NAME = "TREE_SUBMENU_ICON" VALUE = "submenu.gif">

instead of the tree's code:

<APPLET CODEBASE = "."
CODE = "com.java4less.rtree.RTreeApplet.class"
NAME = "TestApplet"
ARCHIVE = "RTreed.zip" WIDTH = 250 HEIGHT = 300>