Excerpts from Mike Meyer's message of Tue Nov 22 22:56:49 -0700 2011:
I'm trying to use gkrellm (because I've already got the configured the way I want them) as a status bar with XMonad. I read the faq, tweaked my xmonad.hs (a modified copy of the original, attached) and set the dock_type to 1 (which can be done with a config option in recent versions of gkrellm).
Doesn't work. gkrellm stays in floating space, and the windows don't shrink to allow it any space. I did try xmobar, and that worked as expected.
One thing is to run xprop _NET_WM_STRUT_PARTIAL and click on the gkrellm to confirm it's asking to reserve the appropriate space. (Setting struts to be avoided with avoidStruts.) Also add manageDocks to your manage hook. This is the bit that unmanages DOCK windows. -- wmw