MenuStrip is the ToolStrip family of control's replacement for MainMenu. It also handles the majority of key handling in the menu activation case and has special logic around Form.MainMenuStrip. There are special MDI features around MDIWindowListItem as well. MenuStrip in this discussion refers to both the entire tree of MenuStrip, ToolStripMenuItems and the associated dropdowns (ToolStripDropDownMenu) collectively and to MenuStrip proper (the top level container only).