Fbpanel is a lightweight, NETWM compliant X11 desktop panel.  It works with
any NETWM compliant window manager (xfwm4, sawfish, openbox, metacity, etc.)
It currently provides and features:

  - Taskbar, launchbar, and pager
  - Show desktop button (iconify or shade all windows)
  - Image viewer and volume control
  - Text and digital clock
  - System tray (notification area)
  - Menu with support for freedesktop.org application menu
  - CPU, network, memory, and battery monitors
  - General monitor (to display output of configured command)
  - Ability to replace windows' icons
  - Transparency support
  - Customizable size and screen position
  - Ability to run many instances each with its own configuration
  - Modest resource usage

WWW: http://fbpanel.sourceforge.net/