[10] One of the project's guidelines is that the source code is intended never to exceed 2000 SLOC, and options meant to be user-configurable are all contained in a single header file.

When invoked, usually by a user-configured key combination, dmenu displays a horizontal menu of its stdin stream at the top edge of the screen.

When a choice is made, dmenu sends the selected text to stdout, which is usually piped into a shell to launch the program.

dmenu is similar in function to application launchers such as Katapult or GNOME Do for Linux or LaunchBar or Quicksilver for Mac OS X in that it allows quick launching of programs from a graphical environment using the keyboard.

In addition to dwm,[13] dmenu is often used with other window managers like xmonad,[14] or Openbox,[13] and other software like the uzbl web browser.