When working with other users, you can share preferences by copying or making aliases to just one InDesign Defaults file, ensuring that all users have the same preferences. But the InDesign Defaults file is not cross-platform-compatible, so Windows users cannot use a Mac user 's file or vice versa.
Except for shortcut sets, color profiles, the InDesign Defaults preferences file, plug-ins, and scripts, cross-platform users can share InDesign support documents. Otherwise, sharing file between PC and Mac users is very simple, thanks to a variety of disk- and network-based utilities now available for both platforms.