is a slick menu and dock app for Linux systems which offers a wide range of customization options. In addition to the familiar menu-based app launcher, aDeskbar also includes nice features like drawers (similar to OS X stacks) and widgets for quick actions like invoking a terminal, logging off, or shutting down your system. Visual options abound, too -- opacity, position, hover effects, background color, and hiding options are all customizable.
As Webupd8 points out
, aDeskbar is designed for use with the OpenBox window manager, but it works just fine with Gnome and XFCE as well. It's an extremely flexible and powerful launcher and well worth taking for a spin on your favorite distro.