FreeFileSync is a free and open-source program used for file synchronization. 2 paths can be mapped (presented my default in the container as /path1 resp. /path2), be sure to only access things through those, writing somewhere else in the container filesystem would fill your Docker filesystem really quickly. The appdata folder is mapped at /home/freefilesync/ and will contain logs, config and can be used to store profiles. Do NOT map anything into /home/freefilesync anymore as that would cause the permissions to be changed on your data. Notes: If the window does not seem to respond to mouse input it is because FreeFileSync's donation popup was spawned behind the main window. Drag the window a bit to reveal it. Right-clicking in the blank space allows opening other instances.