This tool will sync in only one way, this means the source directory will not be changed and only the destination directory will be affected.
By switching off the option "Delete on Destination" you can keep all files backed up even if it no longer exist on the source directory.
You can also choose whether or not to copy the hidden files and directories.

Key features:
▪ Configure as many slots as you want with different folders and configurations.
▪ Synchronizations are fast, only the changes are applied.
▪ Option to Quit OneWaySync, Sleep or Shut Down the computer, or execute a custom script once all synchronizations are complete.
▪ Optionally copy only the photos and videos from an iPhoto/Photos Library and neatly organize all files with the structure of your liking.
▪ Export Music, Movies, TV Shows, Music Videos, Home Videos, Podcasts, iTunes U, Audiobooks, Tones, Books and Playlists from your iTunes Library.
▪ Synchronize the Finder's label colors.
▪ Easily queue slots to be synchronized one after another.
▪ Option to delete files on the destination that no longer exist on the source folder.
▪ Option to copy hidden files and directories.
▪ Option to start copying as soon as OneWaySync is executed. (useful for creating schedules to run this tool from iCal for example).
▪ Option to write on log files all the operations perform during the synchronizations.
▪ Safely cancel synchronization at any time. You have the option to continue next time you synchronize.
▪ Mix 2 or more folders by setting the same destination on different slots and turning OFF "Delete on Destination".
▪ Perform multiple synchronizations simultaneously.
▪ Follow folders in case the name or location has changed.
▪ Scriptable, all actions can be automated using Apple Script.

Compatibility: OS X 10.6 or later

Home Page - http://oktoid.com/onewaysync/index.html