I will go through the steps to install ArdourXchange on OS X to be used with Ardour(http://ardour.org/) or Harrison Mixbus(http://mixbus.harrisonconsoles.com/).
First, we need to get Wine(http://www.winehq.org/) installed. MacPorts is an easy and safe way to build and install Wine on OS X. Follow the instructions here(http://www.macports.org/install.php) to install MacPorts. Note, you will be required to install Apple's Developer Tools from your OS X DVD or download it from ADC(http://developer.apple.com/) if its not installed already. Once MacPorts is installed, open a terminal and enter the command below.
$ sudo port install wine
This will run for a bit, and usually starts the big fan on my MacBook while its building. You should see an output like below if all goes well.
---> Computing dependencies for wine
---> Fetching wine
---> Verifying checksum(s) for wine
---> Extracting wine
---> Applying patches to wine
---> Configuring wine
---> Building wine
---> Staging wine into destroot
---> Installing wine @1.0.1_3
---> Activating wine @1.0.1_3
---> Cleaning wine
To test try getting the version(yours may differ).
$ wine --version
Now run the ArdourXchange setup.exe, note your path to the EXE may differ:
$ wine Downloads/setup.exe
Once the setup has finished, start up Mixbus and AAF files will show up in the open session dialog. Opening them will start the ArdourXchange(http://www.avtoolkit.co.uk/) conversion.