FoldersSynchronizer is an awesome and popular utility for MacOS X which synchronizes and backs-up files, folders and disks. The user can choose one or more pairs of files, folders or disks and then they will be synchronized or backed-up exactly.

FS lets you organize your sync and backup in several sessions to save to a file for a later reuse. On each session you can apply special options like Timers, Multiple Folders, Filters, Exclude Items, Auto-Mount local and remote volumes, launch your own AppleScripts, set how to resolve conflicts, execute an incremental or an exact copy, include locked files...

FS lets you specify global settings like whether FS should display a preview panel listing all the files FS is going to copy, replace and delete. You can also specify to save a log file, to send a log file to a custom email address, to sync and automatically quit the application...  FoldersSynchronizer is available also as lite version and as background-hidden version. FoldersSynchronizer has been successfully tested on MacOS X 10.7 and 10.8.

Backup

When backing up, the destination folder will be upgraded with the newest files, the new files (new entries) and the new Folders (new entries) coming from the source folder. The source folder will be left untouched. FoldersSynchronizer can execute incremental or exact backups. The incremental backup (default) never deletes items. The exact backup deletes from the destination folder, all the items no longer existing in the source folder, and it never deletes items from the source folder.

Synchronization

When synchronizing, the old files will be replaced with the newest files in both directions. The new files (new entries) will be copied in both directions, as well as new Folders. The old Folders will not be replaced entirely by the newer ones, as the Finder used to do, but their content will be updated with the most recent files, the new files (new entries) and new Folders (new entries). FoldersSynchronizer can execute incremental or exact synchronizations. The incremental synchronization (default) never deletes items from the folders. The exact synchronization deletes from a folder, all the items no longer existing in the mirror folder.