Note: Most of the documentation here moved to the ACE+TAO doxygen website, so please check here.
tao_imr Guide - Guide to the commands for the tao_imr application.
The Paper - A paper that has a general description of the IMR. This is also where to look to find information on the inner working of the IMR. Be warned, it was written a while ago and there has been several changes since then in the implementation.