With RokNavMenu, framework core part, the theme provides two specific menu options, Fusion and SplitMenu. Both are configurable in the Gantry Menu widget settings, and also individually for each menu item.
Fusion with MegaMenu
Fusion is a powerful, Mootools enhanced, CSS dropdown menu. It has support for multiple columns of varying widths, inline icons, distribution control, animation control plus many other features.
SplitMenu is static, multi-tiered menu option. Parent items, and 1st level children appear horizontally in the menu bar, and all subsequent children in the sidebar.