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FreeFileSync is a free Open Source software to synchronize files and synchronize folders available for Windows, Linux and Mac OS X. It is designed to be easy to use while having nice visual feedback along the way.

CrashPlan lets you automatically back up your hard drive to another computer. The program offers secure cloud storage, in addition to local backups, and continuous, minute-by-minute backup. All backed-up files are encrypted.

SyncBack is a backup and file synchronization software that allows backing up and synchronizing files to the same or different drives, to different media (CD, DVD, Flash, zip), or to a remote server.There are three versions of SyncBack available: SyncBack Freeware, SyncBackSE (shareware) or SyncBackPro (shareware).

FastCopy is the fastest copy, delete, & sync software on Windows. It uses modern checksum verification to ensure copy accuracy and data integrity. It handles long Unicode path names over MAX_PATH (260 bytes), and automatically optimizes copy mode operations between the same storage device, or different storage devices.

SyncToy is a free PowerToy designed by Microsoft, that provides an easy to use graphical user interface that can automatically synchronize local or network files and folders, but not WebDAV-, "Windows Mobile" files or folders and no triangle-sync as only Allway Sync, Synkron, SyncLess or GoodSync can do. No VSS-support, not portable. SyncToy can manage multiple sets of folders at the same time; it can combine files from two folders in one case, and mimic renames and deletes in another case. Unlike other applications, SyncToy actually keeps track of renames to files and will make sure those changes get carried over to the synchronized folder. »

Create Synchronicity is a nice, lightweight backup program with a very user-friendly - yet powerful - interface, that synchronizes files and folders extremely quickly (it can even recognize paths such as "MyUSB"\MyFolder, and locate the USB drive called "MyUSB").Its open source, fully portable, and multilingual ; and it can schedule backups and has many advanced options like DST correction and regexp settings.

Areca Backup is a file backup software which can be run on Windows or Linux. It creates backup copies (which can be encrypted and compressed) of your files and stores them on external drives, USB keys, FTP servers, supporting incremental, differential and full backups. It also allows you to browse your backups and navigate among different version of the files contained in your archives.

DirSync Pro (Directory Synchronize Pro) is a small utility for file and folder synchronization without bidirectional file-deletion. DirSync Pro can be used to synchronize the content of one or many folders recursively. In difference to Allway Sync, SyncBack or Synkron in the bidirectional synchronizing mode no files can be deleted!Using DirSync Pro you can make incremental backups. Only new/modified/larger files would be copied.Use DirSync Pro to easily synchronize files from your desktop PC to your USB-stick.DirSync Pro is programmed completely in platform independent Java. »

Allway Sync is a file and folder synchronization software for Windows.

A graphical interface for the Rsync engine that will synchronise files between two computers either locally or over the internet. The beauty of Rsync is that it only transfers the exact part of a file that has changed (differential synchronisation), saving bandwidth and time.

BackupPC is a high-performance, enterprise-grade system for backing up Linux, WinXX and MacOSX PCs and laptops to a server's disk. BackupPC is highly configurable and easy to install and maintain.