ZSKSoft Synchronizer

ZSync is a multifunctional folder synchronizer. Because of its universal approach, it's equally great for synchronizing with laptop, backing up data, publishing web site over the FTP, updating AV databases, synchronizing with remote computer, finding differences between two folders, and much more.

Unlike other synchronizers that merely compare which of two files is newer, ZSync is able to remember the synchronization state and track changes in each folder individually. Thus, the program appears to be more accurate; it detects suspicious changes and prevents conflicts (when the same file changes in two locations.)
The program is easy and convenient to operate. Just a glance at the screen is enough to instantly see the overall status, what has changed, how serious the problem is, and what action is suggested. Gravity levels (changed, suspicious, conflict, etc.) are marked with color. File and folder state is marked with easy-to-read labels, and where some actions are required - the program displays corresponding buttons. If certain files or folders should not be synchronized - just drag them to the "off" category.
ZSync's power is best demonstrated during synchronization with a remote computer (e.g., home and office computers.) Any data transmission channels are good for this: e-mail, flash memory, even the regular floppies. The unavoidable blunders (could not deliver the message, unable to read the disk, etc.) do not cause errors; they only have ZSync try a bit harder and take the necessary steps to ensure your work result's safety.