Emacs input method notification via D-Bus. Tested with GNU Emacs 23.4 and awesome wm 3.4.9.

Just add im-notification.el to your load-path, and then append following lines to your .emacs/init.el:

(require 'im-notification)
(im-notification-setup)

After that configure event listener in your WM. It should be able to tell emacs to send IM information if emacs window becomes inactive or active - emacs lacks hooks for that. See rc.lua for parts of awesome config used by author.