Both Sliding & Drop-Down Submenus (in same menu)
One of the major features of AllWebMenus, included in the "Type" group property, is the ability to set a menu subgroup to appear as a sliding submenu (see also "Sliding Menu" in examples list).
In this particular example, the "Company" submenu slides below its parent item and extra "Indentation" and "Margin" are in use to make the submenu smaller in width.
While in the submenu, hover the "Downloads" item and the 3rd level will appear at the right as a drop-down submenu (instead of sliding).
You can also combine drop-down and sliding submenus. If you click on "Products" its submenu will slide (applied as a custom value in "Products" Type property).
This setup has the big advantage that you can control the total menu height when used in a website column and even if your menu has too many levels to fit, you can use the new "Sub Groups Style+" (see "Style+" example), set it as "drop-down" (just uncheck the "Sliding" option) and AllWebMenus will automatically assign it to ALL subgroups of the 3rd level and beyond.
More info on Sliding Menu Add-in
Example I Example II Example III
this AllWebMenus project file.