xmobar | A lightweight status bar for X11 window managers with UTF-8 and Xft support | Mehr ...
xmobar is a lightweight text-based status bar for X11 desktops written in Haskell and designed to work with (but not limited to) xmonad. It has a variety of plugins allowing the display of system-related data and an extensible architecture that makes it easy to write one's own plugins. xmobar supports displaying UTF-8 text and using TrueType fonts via Xft.