MLVWM is a Macintosh-like virtual window manager for X11 created by Takashi Hasegawa. It supports monochrome and color modes, including System 6, MacOS 7, and Mac OS 8-like themes. It provides a customizable, application-specific menu bar, plus applications & windows menus, multiple desktops, collapsible windows, and supports "swallowing" other small X11 applications into the menu bar as widgets.