Multiple Document Interface
lastmod 2026-11-10created 2021-02-262 edits
Multiple Document Interface (MDI) is a GUI style that opens several child windows inside a single parent window to handle multiple documents at once. Child windows move and overlap only within the parent area, and the menus and toolbars are shared by the parent window. Because MFC on Windows provides an MDI application skeleton out of the box, it was widely used in office software in the past, but window management is cumbersome, so today SDI, which opens a separate window per document, or tabbed interfaces are more common.