Horodruin is a tool to synchronize 2 or more folders at once. It provides several filtering options based on file masks, access rights and more. Unlike many other folder synchronizers, it does not use a specified target folder but synchronizes folders among each other and you can limit copy actions with use of the masks or access rights. It s a little difficult to get started with, but quite flexible once you get familiar with it. The interface provides a preview that shows you which files are synchronized and which aren`t.