MDIDEMO支持两种型态的非常简单的文件窗口：第一种窗口在它的显示区域中央显示"Hello, World!"，另一种窗口显示一系列随机矩形（在原始码列表和标识符名中，它们分别叫做「Hello」文件和「Rect」文件）。这两类文件窗口的菜单不同，显示"Hello, World!"的文件窗口有一个允许使用者修改文字颜色的菜单。-MDIDEMO supports two types of extremely simple document windows: one displays "Hello, World!" in the center of its client area, and the other displays a series of random rectangles. (In the source code listings and identifier names, these are referred to as the Hello document and the Rect document.) Different menus are associated with these two types of document windows. The document window that displays "Hello, World!" has a menu that allows you to change the color of the text.