The development environment (IDE) of Gambas uses several MenuButtons at different places in different toolbars:

Figure 13.7.1: MenuButton in the IDE of Gambas 3

This makes sense if you want to use a complete, but dislocated menu on the program interface in the smallest space. The use of a MenuButton as a single button on the form is unusual. You can not only equip a MenuButton with a menu, but you can also assign a context menu to it, as shown in the Properties window (F4) of a MenuButton.