Vertical menu bar

Currently horizontal, one puts the menu bar vertically. It could be display in a lateral pane or as a floating pallet. Two options at least for accessing to the menus : one at once, that needs a root menu or a selector; one expands them separately.
What do we gain by this way? Mainly some space. If each menu’s entries are illustrated by an icon, one could reduced the width of the pane to the size of the icons and one gets there something like a toolbar. Though, and depending the localization, the function’s name can be long, not mentioning the keyboard shortcuts, all that takes a little bit more space.
At a first glance, it would be less productive than the current position but one can display continuously a menu and without covering the canvas. That helps for the beginner to know the different functions of the app, and to relate the icons of the toolbars. This is maybe the main interest of this idea after all. One can in this sense keep the current menu bar, but its content is displayed in a lateral pane or a pallet