This plugin adds a '--using TOOL' option to the 'bzr diff' command. This option can be used to run an external diff tool in place of the built-in command. It is known to work with a wide variety of tools, including:

fldiff
kdiff3
kompare
meld
mgdiff
opendiff
tkdiff
vimdiff
WinMerge
xxdiff

and other similar tools should work as well. If your favorite tool is not working, try adding it (with appropriate options defined) in the list at the end of 'controller.py'.