Directory Opus, commonly abbreviated as DOpus, is an advanced dual-pane file manager originally developed for the Amiga computer by GP Software, first released in 1990. It features a customizable two-pane interface allowing users to view and manipulate files in two directories simultaneously, serving as a powerful replacement for the standard Workbench file management. DOpus became one of the most popular utility programs on the Amiga due to its extensive configurability, support for file viewers, archivers, and scripting capabilities, before being ported to Microsoft Windows where it remains in development today.