I've been an XMonad user for a while now. The window manager doesn't include any status bar-type functionality, instead relying on external programs. The two most common bars in use seem to be dzen and xmobar. I didn't like the methods for feeding data into dzen, so I went with xmobar. It was tolerable. I added a freedesktop.org notification widget a few months ago and it got a little better. Unfortunately, the text-only interface bothered me a little bit, and there was no easy way to get a system tray working well with xmobar.
This itch bothered me enough that I scratched it last week and wrote an alternative status bar for xmonad: taffybar. The bar is actually very simple and based on gtk2hs. If you find that offensive, taffybar probably isn't for you. Visually, it is very similar to xmobar (I don't really know how much room there is for visual variation in the system bar space). A few feature highlights:
- System tray
- XMonad log widget that works over DBus (so you can restart xmonad and taffybar separately and not worry about pipes filling up)
- Freedesktop notification widget
- Battery widget using UPower
- Time-based graph widgets (similar to those in Awesome)
There is still a lot of work that could be done and a few widgets I want to add, but I wanted to have an early release so people could try it and give me feedback. The documentation is in the System.Taffybar module haddock; unfortunately, hackage doesn't like my package and the build failed, so the documentation is temporarily elsewhere until I figure out how to make hackage happy. The installation goes fine on the machines I've tried it on.
Update (2012-02-17)
It looks like the documentation finally builds on hackage.